d blood, breathing through the medium of water by means of branchiae or gills. This definition, as Baron Cuvier has remarked, is the result of observation; it is a product of analysis, or what is termed in physics an empirical formula; but its accuracy is demonstrable by the inverse method, for, when once duly perceived, we may, in a great measure, deduce from it a knowledge of the entire nature of the beings to which it is applied. Being vertebrated, they must be possessed of an internal skeleton; of a brain and spinal marrow, inclosed in a vertebral column; of muscles exterior to the bones; of four extremities only; and of the organs of the first four senses, situate in the cavities of the head; with other relations not necessary to be here named.

The greater portion of the surface of the earth is covered by the waters of the translucent sea; and wherever continents and the larger islands protrude their rocky bulk, we find them coursed by flowing rivers, or intersected by lakes and marshes. These present in their aggregate an enormous mass of waters, and afford protection and nourishment to myriads of living creatures, probably superior in number and in no way inferior in beauty, to those which inhabit the earth. On land, the matter susceptible of life is mainly employed in the construction and continuance of vegetable species; from these, herbivorous animals draw their nourishment; and this being animalized by assimilation, becomes an appropriate food for the carnivorous kinds, which scarcely amount to more than one-half of the terrestrial creatures of all classes. But in the liquid element, and more especially among the saline waters of the ocean, where the vegetable kingdom is so much more restricted, almost all organized substances are pervaded by animal life, and each lives at the expense of some smaller or feebler foe. There we meet not only with the greatest and most wonderful variety of forms, but also with the extremes in respect to size,—from the myriads of microscopic monads, which, but for artificial means, must have remained for ever invisible and unknown, to the ponderous whale, which surpasses, by twenty times, the bulk of the largest elephant. There, too, we may discover the majority of those magnificent combinations of organic structure, on the relations of which naturalists have established the distinction of classes, or great primary groups; in other words, the sea may be said to contain representatives of each; for, even among birds, those aerial creatures which usually inhabit so light an element, we find species so constructed as to dwell almost for ever on its waves. The mammiferous class is still more fully represented in the numerous tribes of seals, morses, manaties, and whales, all of which require a moist abode, and some of which immediately perish when deprived of it. Most reptiles are aquatic, many insects are so, more particularly in their larva state; and almost all the Mollusca, the Annelides, the Crustacca, and Zoophytes, four great classes, which on terra firma are few and far between, exist in countless numbers in the waters of the ocean. Hence that ancient dictum recorded by Pliny, "Quicquid nascatur in parte naturae ulia, et in mari esse; praeterea multa quae masquam alibi."

But amongst all the teeming wonders which vivify the vast expanse and liquid depth of waters, none so predominate, or are so truly characteristic, as the subjects of our present treatise; nor are any more worthy of our careful consideration, whether we regard the beauty or eccentricity of their forms, the metallic splendour of their colours, or the innumerable benefits which, through the foresight of Providence, they confer upon the human race. We therefore deem it incumbent upon us to exhibit an ample view of the present condition of Systematic Ichthyology; but before doing so, we shall endeavour to add to the interest of the subject by a few general observations.

We may state, in the first place, that we here intentionally refrain from any bibliographical inquiry, or historical exposition of the progress of Ichthyology. If such were complete, or even ample, it would occupy too much of that space which we deem more usefully devoted to the actual condition of the science; and we more willingly set that department aside, when we consider how perfectly it has been presented by Baron Cuvier. We shall, however, briefly allude to what may be regarded as the principal epoch in the progress of Ichthyology. During many remote ages it consisted, in common with all the kindred branches of human knowledge, of nothing more than a few partial and disjointed observations. Aristotle, about 350 years before the Christian era, made some progress towards connecting these together as a body of doctrine; but still it was a feeble body, reposing upon truths (perceived indeed with surprising skill when we consider the scanty data) as yet obscurely known and vaguely expressed, owing to the entire absence of all proper standards for the distinction of species. For more than eighteen hundred years ensuing, the writers on natural history can scarcely be regarded in any other light than as either copiers or commemorators of Aristotle; but about the middle of the sixteenth century, Belon, Rondellet, and Salviani, the true founders of modern Ichthyology, made their appearance (we mean as authors), by a singular coincidence, almost precisely at the same time,—the first in 1553, the second from 1554 to 1555, and the third from 1554 to 1558. Differing from their compiling predecessors, they saw and examined for themselves, and made drawings from nature, if not with the elegant accuracy of modern days, at least with a recognisable exactness. Yet, true to the ge-

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1 From ἰχθύς, a fish, and λόγος, a discourse. 2 See the Tableau Historique des Progrès de l'Ichtyologie, depuis son origine jusqu'à nos jours, in the first volume of the great though unfortunately uncompleted work, the Histoire Naturelle des Poissons. We deem ourselves fortunate beyond our predecessors in encyclopedic labour, in having as a guide in so difficult a subject as that on which the reader is about to enter, the volumes of Baron Cuvier's and M. Valenciennes' signal publication. As far as this great work extends we have availed ourselves of the labours of its authors, and have endeavoured to present the general and miscellaneous information contained in it, as amply as our limits would permit, and in a form and sequence the most advantageous to those unacquainted with the voluminous original. In the present revision of this treatise we have also borrowed freely from the writings of our British Cuvier, whose work on the Comparative Anatomy and Physiology of Fishes, forming part of his Hunterian Lectures, gives the fullest and most accurate view of the animal economy of fishes, and most philosophical account of the skeleton, that have hitherto appeared. We beg also to repeat our acknowledgments to Mr Couch, the acute discoverer and describer of new species frequenting the Cornish coasts, and Mr Yarrell, whose work on British Fishes is facile princeps among works illustrative of local Ichthyology. nus of their time, they continued to attach much more importance to the ascertainment of the names which the species bore in the classical pages of antiquity, than to the composition of their history, as it were afresh, by the light of nature and their own knowledge. Nevertheless, they rectified as well as extended the observations of Aristotle, and laid a positive foundation of the subject, by figures and descriptions of a certain number of well-determined species. About the close of the seventeenth century, Willughby, and his illustrious friend John Ray, gave for the first time a history of fishes, in which the species were not only clearly described from nature, but distributed in accordance with characters drawn solely from their structure, and in which we are no longer unnecessarily burdened with inapplicable passages from either Greek or Roman writers. Finally, about the middle of the eighteenth century, Artedi and Linnæus completed what the others had commenced, by establishing well-defined generic groups, consisting of ascertained species precisely characterized. From that period it may be said that no radical defect existed, nor any obstacle in the way of a gradual perfecting of the system, which could not be overcome by zeal, accuracy, and perseverance. Nevertheless, it is to the genius of Baron Cuvier that we owe the gigantic stride which has been made in our own more immediate days.

It is only by a profound study of the whole animal structure that we can, to the extent of our limited intellect, correctly appreciate that part of the works of the great Creator, and get some insight into the branching and anastomosing affinities by which the almost numberless kinds of living beings are linked together. Many years spent in anatomical investigations gave Baron Cuvier such a knowledge of the mutual dependence of the various parts of the organism of each of the numerous species which came under his observation, that he was able, from the inspection of a single bone, to reconstruct, mentally as it were, the animal to which it had belonged, and to assign the species its place in the system of nature. This great step in the history of Zoology placed its discoverer in the first rank of the cultivators of the science. In none of the greater divisions of the animal kingdom were Cuvier's labours, in forming a natural arrangement of the species, of more value than in the class of Fishes, the lowest of the vertebrata, or of that division of animals whose proper character consists in the possession of a central bony axis on which the soft parts are sustained, and from which the motile powers diverge. The Latin word used above has been adopted into the English scientific language, though by many the more Anglicised term of "vertebrals" is used, and we call the internal chain of bone the vertebral column, while its several successive component joints are named "vertebrae." The German equivalent of vertebrata is "wirbelthiere."

We must remark, at the outset, that neither this term of Vertebrata, nor any other definition of a group which the ingenuity of man has hitherto devised, is logically correct. In Mammals, indeed, the highest class of the division, the internal bony frame is strong and massive, and fitted to support the limbs, by which, with the firm earth for a fulcrum, the animal moves through a medium greatly lighter than itself. In Birds, too, constituting the second class of the division, the bones of denser texture but more slender form and often hollow, are admirably fitted for sustaining the powerful muscles exercised in the maintenance of extended aerial flight; and in both classes, the turning joints of the vertebral column, and more especially of the cervical portion of it, are adapted to the various motions of the animal, and for enabling it to rotate its head from side to side, and survey whatever comes within its field of vision. As we descend to the less highly organized vertebrals, we come to other and remarkable modifications of the spinal column. In the third class, or the Reptiles, there is one order, namely, that of the Ophidia, or Serpents, whose locomotion is performed by creeping without external limbs, and solely by the flexibility of the vertebral column and the muscles attached to it, and to its appendages the ribs. The vertebræ are accordingly much more numerous in these animals than in any others, and their motions on each other more extensive. In another group of the same class the vertebrae of the body are soldered together by bone, and power of motion is preserved only in the neck and short tail. A third group, named Amphibians, are fishes in their embryonic or tadpole condition, and undergo a kind of metamorphosis in becoming terrestrial and air-breathing creatures. A fourth remarkable group, of which only a few species have been hitherto detected, presents, with much of the piscine form, the peculiarity of the existence of both gills and lungs, and a residence in water during life. In the Fishes, the proper subjects of this treatise, and the lowest class of vertebrated animals, there is a large group named by some authors Cartilaginei, or Chondropterygi, because the internal skeleton remains in the state of cartilage, the bony structure being wholly absent in some species, and in others only very partially present; and thus the precision of one part of the character of the vertebrata given above is impaired. In certain of the Cartilaginei the joints of the column are obsolete, and flexibility is substituted for the turning motions indicated by the word vertebrae. These brief notices point at some of the difficulties which beset the zoologist when he endeavours to convey the knowledge he has acquired to others, by concise and definite phrases. Yet however difficult it may be to construct a correct definition, it is certain that the idea of the type of an animal group may be conceived in the mind, on the basis of exact observation and legitimate deduction, in proof whereof the reader is confidently referred to the works of Professor Richard Owen of the British Museum, and particularly to his treatise On the Archetype and Homologies of the Vertebrate Skeleton.

The vertebrated animals agree in having a spinal chord or elongated bundle of nervous filaments running along the body, and protected by bony arches composed of the neural apophyses, or processes which rise upwards from the body or centrum of each vertebra. The anterior expansion of the spinal chord, named the brain, is most fully developed in the higher classes of vertebrals, and is comparatively very small in fishes whose encephalon has the character of a series of ganglions, or knots of nervous matter, arranged in single succession or in pairs. In the lowest known form of fish, the Lancelet, the whole vertebral column is merely a pulpy nervous chord invested by a membranous sheath; and Pallas, the first describer of this animal, ranked it, in accordance with the progress that science had made in his time, among the Slugs. In all the vertebrals the vascular trunks and organs of digestion are protected by the inferior processes and diverging appendages of the vertebrae; and the type of this division of animated beings is essentially tetrapodal (fig. 1), though in some groups one or both pairs of limbs are either rudimental or absolutely wanting—examples of these deviations from the ordinary type being most frequent in the classes of Reptiles and Fishes. The four limbs are produced in lateral pairs; and in fishes the first pair are named pectoral fins, and the second pair, being situated on the ventral aspect of the fish, are called ventral fins.

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1 On the Archetype and Homologies of the Vertebrate Skeleton, Svo. London, 1849. Also Report of the British Association, 1846—On the nature of Limbs; Richard Owen, &c., Svo. London, 1849. fins, even though their relative position, as is the case in some kinds of fish, should be in front of the pectorals, when they than in other vertebrals, and only in a very few diminutive Introduction, or almost obsolete. Lubricated by the surrounding medium, it needs no lachrymal gland; and as the light is tempered greatly by a small increase of the depth at which a fish glides through the water, few species have anything like eyelids or nictitating membranes. The function of nutrition is very active, the appetite being very generally voracious, digestion remarkably rapid, and the growth, when suitable food is abundant, extremely rapid. The reproductive power, also, is exceedingly great. Destined to pass their whole lives in a medium whose variations of temperature are much more limited than that of the atmosphere which the other vertebrals breathe, but whose conducting power is greater, the temperature of fishes exceeds only by a few degrees that of the water in which they swim, and their blood is cold. A less vigorous respiration, therefore, suffices to keep up the animal heat, and the oxygenation of the blood is accomplished by the agency of the water on certain vascular organs named gills. Through these organs venous blood is propelled by a simple heart, consisting of one auricle and one ventricle. In these and various other parts of their organization, fish preserve permanently structures that exist in the higher vertebrals only in an early stage of their embryonic development. Palaeontologists have ascertained, moreover, that fishes were the first of the vertebrals which appeared on the theatre of the earth's history, and at an epoch long antecedent to the deposits in which the remains of the higher animals are found. These primitive fish, however, were not types of the lower forms of the class, but, on the contrary, many of them were powerfully built, and resembled the saurian reptiles in parts of their structure, so that they were at least on par with the more highly organized fishes of the present day. We have not learned that the remains of fish having the embryonic vermiform shape, have been discovered in the oldest ichthyogenous deposits.

The Salmon is a familiar example of one of the more common forms of a fish, and one frequently quoted as being pre-eminently qualified for cleaving through the liquid element in which it lives; but there is a vast variety of shapes to be found in the class. The common Salmonoid form (fig. 2) of the osseous fishes passes in different species, by compression and abbreviation, to the thin vertical disks of the Chaetodons or Balistes (fig. 3), or, by compression and elongation, into the ribbon-form of the Gymnatri and

obtain technically the name of jugular fins. In the above woodcut we have a front view of Cheirometes caudimaculatus, belonging to a group of fish which actually walk at times on their four limbs. The vertical fins of fishes are of a different nature, and the rays which support them, whether jointed and soft, or hard and spinous, are not parts of the interior skeleton, but belong properly to the skin or dermal skeleton. The fins that rise vertically in the mesial plane of the back, whether one or more, are named "dorsal." Those from the opposite ventral aspect, situated in all cases posterior to the vent, and therefore appertaining truly to the tail, are termed "anal," and the solitary fin at the end of the tail is named the "caudal." Arvedi denominated the fish which have spinous rays on the back, Acantoptyergians, and those which have only flexible and jointed rays, Malacoptyergians—other groups having however been previously detached by the forms of their branchial apparatus, or the cartilaginous condition of the skeleton. Among the Reptiles there are species which have dermal crests on the back or tail, supported by rays, and analogous to the vertical fins of fishes.

In the great majority of vertebrals a lateral symmetry exists externally and in the skeleton; only one group of fishes, namely, the Flounder family, presents a remarkable dissimilarity in the two sides of the fish.

All the vertebrals also agree in the separation of the sexes, two individuals being required for the reproduction of the species.

SECTION II.—THE EXTERNAL FORM AND CHARACTER OF FISHES.

By using the comparative terms of highest and lowest class of vertebrals, we do not imply that there is any deficiency in the structure of fishes which constitute the fundamental group, for every creature was perfectly organized when called into existence by the fiat of the Creator for the functions he destined it to perform; but He, having designed the fishes to play a part in the scale of nature requiring less intelligence, has furnished them with a simpler nervous system and less sentient organs, a more obtuse sense of touch, restricted organs of smell and taste, and an acoustic apparatus shut up within the head, without any exterior ear or auditory canal for collecting and conveying the vibrations by which sound is produced and transmitted. Light being required to enable the fish to discover its prey or avoid its enemies, the eye is larger in many of them Totally opposed to these is the Leptocephali (fig. 4). Totally opposed to these is the Leptocephali (fig. 4). Totally opposed to these is the Leptocephali (fig. 4).

square box-like shape of the cubical Ostracions (fig. 5), the pyramidal form of others of that tribe, or the round bladder-like figure of the inflated Diodons or the hard-scaled spheroid Monocentris. We have examples of a slender elongated cylindrical form among the Synaptidae or Pipe fish, and among the Eels (fig. 6), Lamprays, and Sharks. Indeed, the vermiform type exhibited by embryos of vertebrals in their earliest stage, is persistent in many fishes, which by the assemblage of other points of their structure enter totally different groups. A depressed, dis-

cold shape, with the appendage of a whip-like tail, is common among the Rays (fig. 7) and their allies; and in the Flounder family we have nearly the same external form produced by compression, and that lateral dissimilarity already alluded to. Other forms, curious from their gro-

tesqueness, or from the redundancy of certain parts, are not uncommon; and we need not adduce other examples than those which exist among the Lophiidae, Gobiidae (fig. 8),

Pristidae, Sclerogenidae (fig. 9), Situridae, or Acanthuridae. Some of the forms which we have thus noticed in general terms, and others which the woodcuts exhibit, are ill calculated for swift progression, and the small and delicate fins of the Ostracions, for instance, can serve little more than the office of rudders to the inflexible scaly case from which they protrude. The chief organs of locomotion in the rapid swimming fish is the tail, which, in a majority of such fish, equals or far exceeds the trunk in length. It sculls a fish along like an ear worked at the stern of a boat. In the vermiform apod fish, and in many Cartilaginæ, swift motion is produced by lateral undulatory strokes of the entire body and tail. When the body is suspended in an element of the same or nearly the same specific gravity with itself, it is moveable by a slight impulse; and we find, accordingly, that if the limbs exist, they are more tender than the analogous members of the higher classes, and that the want of one or both pairs is more common than in other classes.

Before we enter on the consideration of the proper vertebral skeleton, it may be well to premise that the bones, or hard parts of fishes, are primarily divisible into those of the—1. Neuro-skeleton or endo-vertebral series; 2. The Splanchnic-skeleton, for the special protection of certain organs; 3. Dermo-skeleton, parts, as the name denotes, of the cutaneous system, and analogous to the exterior skeletons of the lower divisions of animals.

SECTION III.—THE OSTELOGY OF FISHES.

The structure and growth of bone have been described elsewhere; and it is sufficient to say here that it consists of animal matter, with diffused earthy particles, chiefly of being adapted by their degrees of firmness and hardness for the shocks they have to sustain. The difference depends chiefly on the quantity of fluid matter in the cells and canals of the bone. In a note the composition of the bones of a cod, after the fluid portions had been evaporated, is given as analysed by Bibra.1 The bones of fishes contain more evaporable fluid than those of the other classes of vertebrals, and also a larger portion of the salts of soda. The animal portion of a Shark's skeleton has much of the properties of mucus, yields no gelatine when dissolved in boiling water, and is not precipitated from the solution by infusion of galls, in which respect it differs from the cartilaginous foundation of the bones of beasts. The unossified skeleton of the Lamprey holds only 1½ per cent. of earthy salts. In the vascular canals, which are permeated by the vessels that deposit the bone and carry on its circulation, there is usually some oil, which is composed chiefly of oleine, and is easily converted into soap, and then produces oleic acid, glycerine, and a minute portion of margaric acid. It has odour, and for the most part a yellow colour. In the Belone and Lepidosiren it imparts a deep green colour to the bones. The bones of fishes continue to grow in size almost throughout life.

The limits of this treatise do not admit of a detailed account of the skeleton and other parts of the structure of fishes, of all which, in connection with many admirable remarks on the homologies and analogies of the several parts of ichthyic structure with the corresponding parts of the other vertebrals, the student will find a full account in Professor Owen's Lectures on the Comparative Anatomy and Physiology of the Vertebrate Animals. So complete a work, so easy to be procured, renders it unnecessary to introduce more anatomical details here than are absolutely requisite for the understanding of the systematic review of the class which follows; and these we shall borrow from the work referred to, as being the best authority existing.

The first step in the knowledge of the skeleton of a fish, or of any other vertebral, is the determination of the vertebral segments, or natural groups of bones which compose the skeleton. A vertebra is defined by the Professor to be one of those segments of the endo-skeleton which constitute the axis of the body, and the protecting canals of the nervous and vascular trunks: such a segment may also support diverging appendages. The elements of a vertebra are—1. The body or centrum, from which the others radiate; 2. Two neurapophyses, which, rising upwards, form the neural canal, that incloses and protects the longitudinal central chord of the nervous system; 3. Two parapophyses or transverse processes; 4. Two pleuroapophyses or costal processes; 5. Two hemapophyses, which form, with the centrum, a canal for lodging the central organ and large trunks of the vascular system. This canal is on the ventral, that is, the opposite side of the centrum to the neural one, and is less regular and more interrupted. 6. A neural spine, which crowns the neurapophyses, or is interposed between their tips, and is very conspicuous in the figure of the skeleton of the perch, as it is in most fishes. 7. A hemal spine. 8. Two diapophyses or upper (anterior or proximal in fishes) transverse processes of human anatomy; and, 9. Two zygapophyses or oblique processes.

In fishes a complete typical vertebra can only be obtained from the head; in the rest of the column the hemapophyses are always absent or unossified; their hemal canal being formed by modifications of the parapophyses. The number of vertebrae is governed by the number of pairs of nerves that unite with the spinal chord, and varies greatly in different species, being very numerous in the verniform or serpentine Apodes, and some Plagiostomi, and few in the Plectognathi. In many species they are extensively anchylosed. The earlier stages of vertebral development are permanently represented in the lowest fishes. In the Lancelet, which is at the bottom of the scale, the entire vertebral column consists of a gelatinocellular chord and its membranous sheath. In the Lam-

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1 Chemical composition of bones of the cod after drying—

| Substance | Percentage | |---------------------------------|------------| | Phosphate of lime with trace of fluate | 57-29 | | Carbonate of lime | 4-90 | | Phosphate of magnesia | 2-40 | | Salphate, carbonate, and chlorate of soda | 1-10 | | Gluten and chondrin | 32-31 | | Oil | 2-00 |

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Bibra, Owen's Lectures, &c. prey, cartilaginous arches and spines are added above the "chorda," in the membranous wall of the neural canal, and in the tail also beneath it. In the Sturgeon and Chimaera the bases of the cartilaginous arches inclose the "chorda." In the Lepidosiren, the neural and haemal arches and their spines are ossified, but the centraums are still confluent as a dorsal membrano-cartilaginous chord; and Agassiz has shown that this was the condition of the vertebrae of the most ancient fossil fishes—those of the Silurian and Devonian rocks. In many Sharks and Rays the "chorda" is encroached upon by osseous or cartilaginous convergent laminae, and by concentric, successively shorter, centripetally developed cylinders, and is thus reduced to a string of gelatinous beads, each bead occupying the interspace between the opposed concave surfaces of the vertebral bodies. This moniliform state of the "chorda" is persistent in most osseous fishes; whilst in some others the gelatinous biconical segments of the "chorda" are insulated by the completed centripetal process of ossification; and in one genus, the Lepidostomus, they are converted into osseous balls, fixed to the fore part of each vertebral body, which plays in the concavity or cup of the vertebra next in advance. The slightly compressible jelly-bags that fill the concave opposing articular surfaces of the vertebrae are admirable contrivances for facilitating the motions of the fish. The neural and haemal arches and spines are bony in all osseous fishes; and in all fishes chondrification and ossification of the vertebral column commences in these arches.

The skeleton of fishes presents many instances of what Owen terms "vegetative repetition of perivertebral parts." There being no distinct neck in fishes, we find no peculiar cervical vertebrae, the series posterior to the head consisting of abdominals and caudals. With the former the ribs are connected, and in the latter the haemal canal is formed by the deflection and union of the parapophyses, as mentioned above. The pleuroapophyses, or ribs, are generally articulated in fishes to the ends of the parapophyses, but in Platichthys and Polypterus they articulate with the bodies of the vertebrae. In the Salmon and Dory they continue to be attached to some of the parapophyses after these are bent down in the tail to form the haemal canal and haemal spines. The Diodontidae, Ostraciontidae, Fistulariidae, Synaptidae, Cyclopteridae, and Lophidae, are destitute of ribs.

Slender supplementary ribs often issue from near the head of the ribs, passing outwards and backwards between the lateral muscles. Professor Owen names them "epipleural spines." They are highly developed in the Salmonidae, Clupeidae, and Scambridae. In the common Herring, dermal bones are connected with the lower ends of the ribs, and have been called, though erroneously, sternal bones, since they do not belong to the endo-skeleton.

In osseous fishes, imposed above the proper neural spines, there is a second row of spines belonging to the dermo-skeleton, of greater or less extent, and serving to support the dorsal fin or fins. From their bases other spines of an inverted shape usually descend into the intervals of the neural spines, and are hence named by Owen "interneural spines." These interneurals are sometimes in lateral pairs, as in the Pleuronectidae, the Chaetodipteridae, Zeider, and some other compressed fish.

The modifications of the dorso-interneural and dermal spines are repeated on the ventral aspect, posterior to the anus, producing inter-haemal and dermo-haemal spines which support the anal fin. Each dermal spine or ray is either readily divisible into two laterally, or presents a furrow indicative of a tendency to such a division. The caudal fin is extended also on compressed intercalary and dermal spines, diverging from a few coalescent and abbreviated caudal vertebrae. In the base of the caudal formed of these elements, the haemal spines are more developed than the neural ones in very many species, as in the Salmonidae, and then they press upwards the short and almost obsolete vertebral centra which form the tip of the spinal column, and into which the spinal marrow is not extended. This larger development of the haemal processes elongates the upper lobe of the fin, and gives a very unsymmetrical form to the caudal of Sharks, Sturgeons, and Elephant fish. Fishes possessing such a caudal are named by M. Agassiz "heterocercal;" and those with a symmetrical caudal fin he designates "homocercal," including, however, in the latter group the existing fish wherein the obliqueness of the caudal vertebrae does not affect, in a decided way, the shape of the caudal fin, the Salmonidae, for instance, being homocercals.

Among the palaeozoic fishes the heterocercal fishes greatly predominate; all that have been found in the magnesian limestone, and in older strata, having the superior lobe of the tail prolonged. The only existing osseous fishes that are recognised by M. Agassiz as heterocercal belong to the genus Lepidostomus.

The size, number, and shape of the vertical fins depends on the development and grouping of the accessory and intercalary spines, the proper neural and haemal spines of the endo-skeleton showing no direct indication of the existence or position of those fins; but it is convenient to notice them in connection with the vertebral column, as the systematic arrangements of ichthyologists have had much reference to the number, relative position, and condition of the rays of those fins, in regard of their being simple and spinous, or jointed and forked. We have already noticed the terms Malacoptygian and Acanthopterygian as derived from these varieties of structure. Species occur among the Gobiidae and some other families of fish, in which there is much difficulty in deciding to which of the two groups they belong. In the Lancelet and Lamprey, the dorsal and caudal fins are simply cutaneous folds, with scarcely distinguishable soft fibres for rays. Synbranchus guttatus, and Channomuraena, have nearly obsolete rays at the tip of the tail only; and in Gymnomuraena the folds as well as rays are wanting. The interneural and dermal spines seldom coincide in number with the neural spines. They are often more numerous, but more frequently less numerous. The sucking apparatus on the head of the Remora is an assemblage of peculiarly modified and connected dermal spines. Great development of the dermal spines often renders them powerful weapons of defence, as in Trachinus. The Chimaera, Cestracion, Piked Dog-fish, and Balistes, are... furnished with a stout bony spine at the front of the dorsal fin; and the Sticklebacks (fig. 13) have curious sculptured bony spines in the ventrals as well as in the dorsals. In most Siluridae the pectorals are supported by a strong and dangerous spine. Many of the rays have detached serrated spines on the upper part of the tail; and in paleontology similar spines, named "Ichthyodorulites," are the sole indications remaining of the plagiostomes of former epochs. The Siluroids and Trigger-fish (Balistes) are remarkable among bony fishes for these dermal weapons.

That the skull (fig. 15) consists of a series of four vertebrae modified for containing the cerebral enlargement of the anterior end of the nervous column, has been most fully demonstrated by Professor Owen. Each is divided into a neural arch with which the centrum and parapophyses are more immediately connected, and a haemal arch with its appendages.

A. Beginning next the trunk, the following are the names of the neural arches in the order of their succession:

I. Epencephalic arch. II. Mesencephalic arch. III. Proencephalic arch. IV. Rhinencephalic arch.

AA. The haemal arches are,—1. Scapular or scapulo-coracoid. 2. Hyoid or stylo-hyoid. 3. Mandibular or tympano-mandibular. 4. Maxillary or palato-maxillary. The appendages of the haemal arches are,—1st. The pectoral. 2d. The branchiostegal. 3d. The opercular. 4th. The pterygoid.

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**ENDO-SKELETON**

| Occipital Vertebra | Parietal Vertebra | |--------------------|-------------------| | Basil-occipital | Sphénoid postérieur | | Exoccipital | Grande aile du sphénoid | | Supraoccipital | | | Paroccipital | | | Supra-scapula | | | Scapula | | | Coracoid | | | Clavicle | Troisième os de l'avant bras | | Humerus | Radial | | Ulna | Cubital | | Radius | Os du carpe | | Carpals | Rayons de la pectorale | | Metacarpo-phalanges| |

**FRONTAL VERTEBRA**

| Occipital Vertebra | Parietal Vertebra | |--------------------|-------------------| | Basilaire | Articulaire | | Occipital latéral | Angulaire | | Interspézial | Operculaire | | Occipital externe | Dentaire | | Surcoculaire | Pré-opercule | | Scapulaire | Opéraculaire | | Humbral | Sous-opercule | | Articulaire | Inter-opercule | | Surrangulaire | | | Angulaire | | | Opéraculaire | | | Dentaire | | | Pré-opercule | | | Opéraculaire | | | Sous-opercule | | | Inter-opercule | |

**NASAL VERTEBRA**

| Occipital Vertebra | Parietal Vertebra | |--------------------|-------------------| | Vomer | | | Frontal antérieur | | | Ethmoïde | | | Palatine | | | Maxillaire | | | Inter-maxillaire | | | Pterygoïden interne| | | Transverse | | The bones of the Splanchnico-skeleton constitute in the skull— a. The ear-capsule or petrosal and otolite. b. The eye-capsule or sclerotic and pedicle. c. The nose-capsule or ethmoid and turbinal. d. The branchial arches.

The bones of the Dermo-skeleton belonging to the skull are— a. Supra-temporals. b. Supra-orbitals. c. Sub-orbitals. d. Labials.

I. The Epencephalic arch consists of the basi-occipital, on which there is an excavation similar to one on the first abdominal vertebra, and with which it is articulated through the intervention of a capsule filled with jelly. This articular cup varies from a deep conical excavation common to many fish, to the almost flat surface which it presents in the Holobut, and, what is extremely rare, to a convex surface as in Fistularia. In the Carp, the under surface of the basi-occipital forms a broad triangular plate, on which there is planted the large upper phryngeal grinding tooth. This bone is the centrum of the arch. The ex-occipitals or neurapophyses are articulated one on each side to the basi-occipital, and, in most fishes, they expand on the upper surface of that bone, so as to meet and support the medullary column; but sometimes a space is left between them, as in the Lepidosiren, whose basi-occipital completes the foramen magnum of the skull. The par-occipitals form the upper lateral curve of the arch, and are wedged in between the ex-occipitals and the supra-occipital, which forms the key of the arch, and raises a strong compressed crest-like spine from the whole length of its mesial line; a transverse supra-occipital ridge coming from each side of the base of this spine runs outwards laterally to the external angles of the bone. The supra-occipital is separated from the frontal in the Salmonoid, Clupeoid, Cyprinoid, Murcenaoid, and Salamandroid families; but, in the majority of fishes, it runs forward between the parietals to join the frontals. In Lepidosteus, it is itself divided by a median suture. In greatly compressed skulls, the occipital spine is usually very lofty; and, in Ephippus, its peripheral edge swells out like the crest of a helmet, whence the fish is named the Light-horseman. In depressed skulls, on the contrary, the spine is low and merely projects backwards, as in the Pike and Salmon; while in some it is wholly obsolete, as in the flat-headed Remora. In the unsymmetrical skulls of the Pleuronectidae, it is pushed from its usual place by the par-occipitals, and one of its lateral plates is not developed. In broad depressed skulls the par-occipital forms a strong crest, and exceeds the ex-occipital in size. In Synodus, Callionymus, and Heterobranchus, the par-occipital is visible only at the back part, not on the upper aspect of the skull. The outer projecting process supports the upper fork of the first piece of the scapular arch, sometimes, as in Ephippus, by a distinct articular cavity.

The members of the occipital vertebrae are the parts which are commonly most completely ossified, and in Polypterus they are ankylosed into one piece. Both the par-occipital and the ex-occipital are excavated for lodging the posterior and external semicircular canal of the enormous internal organ of hearing, and the acoustic capsule, or petrous bone, as it is named from its hardness, is intercalated between the par-occipitals and the ali-sphenoids. In the Carp, a chain of ossicles connects the air-bladder with the organ of hearing.

II. The Mesencephalic arch has for its centrum the basi-sphenoid, which is always connate with the pre-sphenoid (belonging to the next arch), and forms with it a long sub-triangular bone (basi-pre-sphenoid), usually split or forked posteriorly, more or less expanded beneath the cranial cavity, and then continued forwards, along the base of the inter-orbital space to near the fore part of the roof of the mouth, where it terminates by a cavity that receives the pointed end of the vomer. This end of the basi-pre-sphenoid is twisted up in the Pleuronectidae. The longer and narrower the skull, the longer in general is the basi-pre-sphenoid. Rarely does any portion of it show on the floor of the cranial cavity, but in the Cod a small part supports the pituitary sac; in Fistularia a transverse ridge of it appears within the cranial cavity, and in some other fishes it sends a small process up on each side. The ali-sphenoids or neurapophyses of this arch are articulated firmly to the sides of the basi-sphenoid, their bases usually expanding over this bone so as to meet and form part of the floor of the cranial cavity. In some fishes, as in the perch and carp, these expanded plates of the bases are raised from the basi-sphenoid so as to form a sub-cranial canal which exists in the Salmonoids, Sparoids, Scomberoids, and is very remarkable in Ephippus, and most fishes that have lofty compressed skulls. It exists in some Clupeoids, but not in the Salamandroid fishes. In deep and compressed skulls the ali-sphenoids are narrow and... high plates, while in low and flat heads their longitudinal axis is the longest. In skulls of the ordinary form, they are sub-circular, and are perforated as in the Carp, or this perforation may be replaced by a deep anterior notch, as in the Cod. Its connections vary with its relative size, and, according as the petrosal, which interposes between it and the ex-occipital, is greater or smaller or wholly wanting. The parietals or spine of this arch are most commonly two in number. In the Cyprinoid and Salamandroid fishes, they unite above by a longitudinal suture (the sagittal); in the Cyprinoid *Catastoma* a mesial rectangular cartilaginous plate interposes between the ossified side plates; in the Salmonoids they soon coalesce; and in some Siluroids they coalesce with the supra-occipital as well as with each other. In the Pike, Perch, and Cod, and most osseous fishes, the parietals are separated from each other by an anterior prolongation of the supra-occipital. The mastoids or parapophyses of the parietal vertebra are interposed between the ali-sphenoids and parietals, and project outwards and backwards farther than the par-occipitals, forming the second strong transverse process at the side of the cranium. This process is developed from the outer margin of the bone. The inner side of the bone lodges part of one of the semi-circular canals. The great cavity named "otocrane," which lodges the proper acoustic capsule or petrosal, whether osseous or cartilaginous, is formed by the ex-occipital, par-occipital, ali-sphenoid, mastoid, and sometimes the parietal and supra-occipital.

III. The Prosencephalic or frontal arch is based on the pre-sphenoid already described in connection with the basi-sphenoid. The orbito-sphenoids or neurapophyses of the frontal vertebra are usually square, but sometimes semi-circular or semi-elliptic, as in the Cod; larger in the *Mantaopteri*, but very small usually in the *Acantopteri*, and cartilaginous in the *Sclerogonidae*. The olfactory nerves pass out of the skull by the superior interspace of the orbito-sphenoids, and the optic nerves by their inferior interspace or by a direct perforation. The mid-frontal bone completes this arch above, and always enters into the formation of the cranial cavity though its major part forms the roof of the orbits. It is single, and sends up a median crest in the Cod, the Ephippus, and some other fishes, but is more commonly divided along the median line. Each of the halves sends up its own crest in the Tunny. In the Salamandroid fishes, each frontal sends down a vertical plate to the sphenoid, thus forming a canal through which the olfactory nerves run. The side walls of this canal make a double bony partition between the orbits. The post-frontals or parapophyses of the frontal vertebra partly underlie the mastoids, and complete their prominent crest.

IV. The Rhinencephalic arch terminates the axis of the skull anteriorly, and protects the olfactory ganglions and nerves. The centrum of the nasal vertebra is named the vomer. Its posterior point is wedged into the under part of the pre-sphenoid; it expands and becomes thicker, anteriorly, where its lateral angles are articulated to the pre-frontals. Its upper surface supports the nasal bone, and its under surface, which enters into the composition of the roof of the mouth, is in many fishes dentiferous. The same is often the case with the palatine bones, which abut against it laterally, and also form part of the roof of the mouth. The presence or absence of these teeth has been made much use of for characterizing genera and large groups of the osseous fishes. In *Lepidostomus* the vomer is cleft by a median fissure. In *Polypterus* it is confluent with the basi-sphenoid. The pre-frontals or neurapophyses of the nasal vertebra defend and support the olfactory ganglions, bound the orbits anteriorly, give a surface of suspension to the palatine bones, and through them for the palato-maxillary arch; and they also give attachment to the large pre-orbital or lacrimal scale bone when this exists. In the Cyprinoids and most Chiropterids the pre-lateral-frontals form part of the interorbital septum. In the *Congeridae* we recognise the pre-frontals in the confluent parts of the nasal vertebra by the external groove conducting the olfactory nerves to the nasal capsules, and by the inferior process from which the palatine bone is suspended. In the *Murciniidae* also the pre-frontals are plainly confluent with the nasal bone, and furnish the well-marked articular surfaces for the palato-maxillary bone. In the Cod the palatine arch is chiefly, but not wholly, suspended to the pre-frontals. The nasal-bone or spine of the most anterior arch of the skull is usually single, and terminates forwards in a thick obtuse extremity. In the Salmonoids and some other fishes, it is broad, but not deep; in *Istiothorax* it is long and narrow; in the *Discoscelis* and *Lophobranchii* it is a short vertical compressed plate, and it is wanting in *Lophius* and *Diodon*, or merely membranous. It is articulated above and behind to the frontals and pre-frontals; and below, either directly or by cartilage, to the vomer. In the Flying Gurnard it has no immediate connection with the vomer; but this is a rare exception. In the Salamandroid fishes, the nasal is divided by a median suture. The horn-like projection from the forehead of *Naseus* is formed chiefly from the frontal bone, a small nasal being articulated beneath. This nasal is trifid anteriorly; its lateral divisions articulating with the pre-maxillaries, as in *Citharinaeus*. The turbinal bone or osseous capsule of the nose, belonging to the splanchno-skeleton, is situated at the side of, or above the nasal; the pre-maxillary and maxillary bones are usually attached to its extremity through the medium of cartilage. In the *Murciniidae*, the normal elements of the nasal vertebra coalesce into a single bone. The spine of this vertebra or nasal bone forms the usual obtuse extremity beneath the skin of the upper part of the snout, and it is dentiferous, as in the *Lepidostomus*; it is intimately confluent anteriorly with the centrum or vomer, the limits being indicated by the interruption of the median series of vomerine and nasal teeth.

This completes a compendious view of the neural arches of the four cranial vertebrae which have for their primary function the protection of the ganglionic brain, in which the spinal chord ends anteriorly. From the complete osseous skull of a fish, there are many descending modifications, until we come to the vermiform Lancelet, which wants the cerebral expansion altogether; the gelatinous "chordas" being terminated by a tapering end, invested by a membrane, without any addition of cartilaginous or osseous coverings.

II. Sense capsules of the splanchno-skeleton intercalated with the neural arches. Some of these have been already noticed. In the *Ammonoecetes*, cartilage is developed for the protection of the acoustic organ, in a skull, otherwise mostly fibro-membranous. (a.) The bones entering into the formation of the otocrane for the lodgement of the labyrinth have been named above; but it is the petrosal which is the bone specially designed to form the acoustic capsule, though in fishes it is less confined to that function than in the higher vertebrals in which it exclusively envelopes the labyrinth. Its ossification commences late in the osseous fishes. It is very small in the Cyprinoids, and in them Cuvier describes it as a dismemberment of the mastoïd; but in the Perch, where it is more developed, he recognises it under its proper name. In the Cod it has a larger size, and the two otocranes are completely separated from each other.

b. The optic capsule or sclerotic investment of the eye is cartilaginous in the Chondropterygians and in semi-osseous fishes, but in most osseous fishes it is bony. An orbit for lodging the eye-ball is formed by the pre-sphenoid, orbito-splenoid, frontal, post-frontal, pre-frontal and palatine bones; its wide outer opening is often circumscribed by the chain of sub-orbitals or scale-bones below, and less frequently by one or more supra-orbitals above. In the Shads, Erythrinus, Citharinus, Hydrocyon, Cyprinus, and many other Malacopteryi, and in Synbranchus, the orbits are separated from one another by an osseous septum, but in general the septum is incomplete or wanting; in Lepidosteus and Polypterus it is double.

c. The nose-capsule is formed by the ethmoidal which enters into the walls of the cranium, and the turbinal which belongs to the nose, other bones, as the vomer and nasal, being accessories. The whole capsule is cartilaginous in cartilaginous and semi-osseous fishes, and the ethmoidal part continues so in many osseous fishes. The cartilaginous capsules and pituitary expansions are proportionally large in the Chondropterygii and Lepidosiren, communicating with each other in the latter by membranous slits; but in the higher fishes they form a pair. The turbinals in osseous fishes are generally thin, more or less elongated, scales situated at the sides of the nasal bone and ascending processes of the pre-maxillaries.

4. Palato-maxillary arch. Of this inverted arch, the palatine bones are the piers, and their points of suspension are their attachments to the pre-frontals, the vomerine, and nasal bones. The arch is completed by the maxillary and pre-maxillary bones, the symphysis of the latter forming its apex. The palatine or pleurapophysis of the nasal vertebra articulates at its peripheral extremity with the maxillary, to which it affords a more or less moveable joint. In the Parrot fishes and Dinodons the articulation is analogous to that of the mandible below, with the tympanic pedicle. In the Salamandroid fishes it is a fixed suture. In Mormyrus these ends of the palatines meet and unite at the mesian line. In fig. 19, representing the jaws of Alepisaurus, the palatines are seen to be strongly armed, each of them having two pairs of tall lanceet-shaped teeth, one pair nearly under the nostrils, the second pair not so tall, further back, and closely followed by ten much shorter ones. The maxillary or humapophysis of the nasal vertebra lies between the palatine and pre-maxillary. On the extent to which these two bones enter severally into the orifice of the mouth, and on their dentiferous or edentulous conditions, many divisions of fishes made by ichthyologists are mainly founded. In the Salmonoids the maxillary joins to the lower end of the pre-maxillary, forming, together with it, the upper half of the border of the mouth, and it supports teeth. The same form prevails with the Introduction. Clupeoids. In Thrissa and Cetilia of this family the pre-maxillary is very small, and the large dentiferous maxillary is prolonged beyond the corner of the mouth (fig. 17). In the Plectognathi the two bones coalesce. In Lepidotes these bones also form a single dentiferous arch, but they are subdivided into many pieces, a condition which seems to have prevailed with the ancient Salamandroid fishes. It is dentiferous and largely developed in Polypterus, but very diminutive in the Siluroids, and wanting in the Murcenidae.

The pre-maxillary, or the nasal spine of the nasal vertebra, is more commonly directed transversely than longitudinally. Its nasal branch, or pedicle, is of unusual length in fishes with protractile snouts, such as the Menidor, Zeide.

Epibulus, Emmelichthys, and others. Commonly, its labial border is beset with teeth; and in many groups of fish it forms, with its fellow and the mandible, the whole margin of the mouth, the maxillaries in that case lying in folds of skin. This extension of the pre-maxillary is well shown in the Alepisaurus, a predaceous Sphyraenoid; there it is closely set by a series of small teeth (fig. 19). The small pony piece above the maxillary in the Trout, Herring, and Pike, seems to belong to the series of mucous or scale bones.

The diverging appendage of the palato-maxillary arch consists of the pterygoid and entopterygoid bones, which are the less constant parts of the arch. They are connate with the palatine in most Salmonoids and Eels, while Muraena wants the entopterygoid, and its pterygoid is disconnected from the maxillary arch. Most fishes, however, have both bones.

3. The tympano-mandibular arch has the true inverted or haemal character, its apex formed by the epi-tympanics or pleurapophyses of the frontal vertebra hanging downwards below the vertebral axis of the skull. In most fishes, its lower end is bifid, and supports two inverted arches, the mandibular and the hyoidian. The meso-tympanic is articulated above to the epi-tympanic and pre-opercular, anteriorly to the pre-tympanic, and by its lower end to the hypo-tympanic, reaching almost to the mandibular trochlea. It is the "symplectic" of Cuvier, and it is confluent in the Siluroid, Muranoid, and some other fishes with the epi-tympanic. The pre-tympanic "cassis" or "os tympanicum" of Cuvier, receives, in its posterior margin, the fore part of the meso-tympanic, and the upper and fore part of the hypotympanic. It is confluent with the latter in Conger and Murana, and it does not join either of these bones in the Lepidosteus. The hypo-tympanic bears the convex articular trochlea for the lower jaw upon its inferior apex. The Epibulus presents a remarkable, much elongated, and slender modification of it, carrying the lower jaw at an unusual distance from the base of the skull, and allowing it to swing backwards and forwards on its long pedicle as on a pendulum. In the Muranidae the tympanic pedicle is a strong triangular plate affixed to the cranium by its base or shorter side, and carrying the mandibular joint backwards beyond the occiput. The mandible or lower jaw is the hemapophysis of the frontal vertebra, and completes the arch below by its ligamentous or bony symphysis with its fellow. Each branch or half consists most commonly of two pieces, sometimes of three or more, the one articulated to the suspensory pedicle being the proper hemapophysis, and the extreme one completing the arch and supporting the teeth being the hemal spine. The diverging apparatus of the tympano-mandibular arch consists of the opercular bones of the gill-cover, which, by its movements, opens and closes the branchial aperture on each side of the head, thereby regulating the currents through the branchial cavity. It may be considered as a kind of short and broad fin. The first or most anterior, and the chief medium of attachment of the appendage, is the pre-opercular, which commonly has a crescentic or angular form. In the Cod it is forked above, and in the Sclerogenyidae the enormously developed second suborbital scale bone crosses the cheek to be articulated to it. The opercular is commonly the largest of the remaining pieces of this appendage, and is chiefly connected with the posterior margin of the pre-opercular, but very generally it is partially attached above to the outer angle of the epi-tympanic. In the Lophius, its posterior margin is coasted by a long slender fin ray, and the sub-opercular, which forms the posterior and lower angle of the gill-cover, carries out the resemblance to a fin by its radiated structure. All the framework of this fin has the form of rays in the Plagiostomes. The lowermost piece, called the inter-opercular, is articulated to the pre-opercular above, the sub-opercular and angle of the opercular behind, and usually to the back parts of the mandible in front. In conjunction with the pre-opercular, it is more elongated in the very long head of Fistularia than the other two pieces of the appendage. It is wanting in the Siluri, and the sub-opercular is wanting in the Shad. In Murana, the small opercular bones are articulated only to the lower part of the tympanic pedicle. The smoothness or serratures of the posterior edges of these bones, more especially of the pre-opercular, and the numbers and situations of the spines which emanate from them, furnish characters to ichthyologists for the discrimination of many species and groups of species.

2. The hyoidean arch is suspended in osseous fishes, as we have already had occasion to say, to the mastoid, through the medium of a fork of the epi-tympanic bone; and its bony arch is completed by the two small, cubical basihyal. The anterior part of the arch is formed by the stylo-hyal, epi-hyal, and cerato-hyal, the first-named being joined at its upper end by ligament to the epi-tympanic, and the others descending from it in succession. The cerato-hyal is the longest and largest, and supports the diverging appendix of the hyoidean arch named branchiostegals or gill-cover rays, and on which the membrane that closes the branchial chamber is extended. The number of these rays varies greatly. They are only three, and these comparatively broad and flat in the Carps, while in Elops saurus they amount to more than thirty. They are of very great length in the Angler, and spread out the gill membrane like a great bag on each side of the head.

In Pisodonophis cancrivorus the branchiostegals are thirty-three in number on each side, very long, and as fine as hairs, and the curves they make in the branchiostegal membrane are different on the two sides of the head.

d. The branchial arches, which appertain to the system of the visceral skeleton, succeed the hyoidean arch, and are more or less closely connected with its key-stone, the basihyal. Six of these arches are usually developed in embryo, and five are usually permanent, four of them supporting the gills, and the fifth circumscribing the opening of the gullet and beset with teeth. This last is called the pharyngeal arch. The arches adhere by their lower extremities to a chain of ossicles, and curving as they ascend, nearly meet at the base of the cranium, to which they are attached by ligamentous and cellular tissue. Each of the first three branchial arches, independent of the basal keel bones, or basi-branchials, consists of three or four pieces, which have a certain elastic or flexible movement on each other. The lowest of these pieces is the short hypo-branchial; the next, the long cerato-branchial, is grooved on the outside, and supports the dentigerous processes, or tubercles, named rokers. Above this is an epi-branchial similarly formed. To it, in the second and third arches, the short, broad, dentiferous epi-branchial is commonly attached. The fourth arch consists of the cerato-branchial, the epi-branchial, and the pharyngo-branchial pieces. The fifth arch usually consists simply of the cerato-branchial element, but in Anobas it supports a pharyngo-branchial. This last-named bone is often expanded, and more or less dentiferous: it is termed by Cuvier "the inferior pharyngeal bone," and the upper dentiferous portions of the arches are called the superior pharyngeal bones." In Cottus, these superior bones are blended into one piece. A peculiar development of the epi-branchial and pharyngo-branchials of the first two or three arches, serves the office, in a group of fishes, the Labriniithibranchii, of retaining a supply of water for moistening the gills when the fishes are temporarily out of their proper element.

1. Scapular arch. This inverted cranial arch is attached to the par-occipital; or to that bone and the mastoid; or to the same bone and the petrosal, as in the Cod; or to the par-occipital and basi-occipital, being essentially the hermal arch of the occipital bone, to which it is constantly attached wholly or in part. In the Eels it is feebly developed, and only loosely suspended behind the skull; and in the Plagiostomes it is removed further back to a distance from its proper vertebra. Its superior piece is the supra-scapula, then follows the scapula, and the arch is completed below by the union of the frequently very strong and firm coracoid with its fellow. The coracoids defend and support the heart, and give attachment to the diaphragm, which separates the pericardial and abdominal cavities.

The scapular arch usually supports a diverging appendage on each side, constituting the pectoral fin. The pectoral fin rays are analogous to the fingers of the higher animals, the lowest ray, when the fin is laid back to the side of the fish, answering to the thumb. The bones which support these rays are homologues of the bones of the fore extremities of the higher vertebrals, and have been named accordingly. In the Cod tribe, and most other fishes, there is, however, no separate representative of the humerus. The radius is of enormous size in the Lampris and in Flying-fish. It is anchylosed to the ulna in Saturus for the firmer support of the pectoral spine, and in Lophius, both radius and ulna are extremely small, and connate with the coracoid. The carpals, usually four or five, but sometimes only two, progressively increase in length from the ulna to the radial side. In the Wolf-fish they are broad flat bones. The metacarpals and phalangeals are in the Cod twenty in number, all soft-jointed, and sometimes bifurcate at the distal end.

In the osseous fishes the pectoral fins present a series of modifications. In the Acantichopterygii the ulnar ray is a hard unjointed spine. In the Gurnards, Choridactylies, and several other genera of Selengonidae, the three lower rays are detached and free, and there is reason to believe that these rays are used like fingers as organs of touch when the animal swims close to the sandy bottom of the sea. The pectoral fins are very largely developed in the Exocoetus; it is also large in Daetogaster, Trigla, and Priotus, as well as in several other forms of the Selengonidae.

In the Cod and Carp there is a single styliform bone, named the epi-coracoid, because it is attached to the upper end of the coracoid. In the Perch, and most other fishes, it consists of two pieces. In Centriscus scolopax, Argyreus comer and Sagamus, it is joined by its lower end to its fellow, thus completing an inverted arch behind the scapular one. The epi-coracoids are absent or are very slender spines in the Wolf-fish, Mullet, Goby, Stickleback, Remora, Cephaloscyllium, the Blennies, Siluroids, and Apodial fishes. The apodial Sandlance, however, possesses the epicoacoids.

Ventral fins. The rays of the ventral fins are supported by two bones, which are named pubic bones, and represent the lower part of an inverted hermal arch. In no fish is this incomplete pelvic arch directly attached to the vertebral column. In all fossil fishes belonging to deposits anterior to the chalk, the ventrals are placed towards the posterior end of the abdomen, and hence, and from the consideration of the position of the rudiment of the ventral in the embryo fish, it may be inferred that these pubic bones are the homologues of the last abdominal vertebra. In Acanthopteri the anterior ray of the ventral may be spinous.

In the Malacopteri all the ventral rays are soft, multi-articulate, and bifurcate. The normal position of the ventral homoplasmy is under its proper vertebra, but the relative length of the pubic bones in different fishes, places them under the abdomen, or pectoral fins, or gills; hence Linnaeus's division of the fishes into abdominal, thoracic, and jugular, and, when the ventrals are wanting, apodial. Cuvier substituted the term subbranchial for thoracic and jugular. The ventrals are better developed in the Plagiostomes than in other fishes, and connected with this fin, in the male Plagiostomes and Chimerae, there is the peculiar intermittent organ of generation named the "clasper."

In the Gobies (fig. 22) and Gonorhynchus, the ventrals are united to each other by a membrane; and in Cyclopterus, Gobiesox, and

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1 In adopting Professor Owen's osteological system, we have thought it proper, to avoid mistake, to use his own words as often as we could; but as our extracts from his elaborate and exhaustive work are very compendious, and not always in the order he pursued in his lectures, they are not marked by inverted commas as quotations. c. Dermal or Exo-skeleton. To this system the scales belong, each being secreted, like a tooth, in a depression or pocket of the skin, to which it adheres under the cuticle. They are very generally imbricated with the posterior end extruded and free, but the skin usually extends over the surface of the anterior end to a greater or less extent; or the scale may be entirely imbedded beneath the cuticle. Professor Agassiz considered the form of the scales to bear so strong a relation to the rest of the ichthys structure and the general economy of a fish, that he founded upon it his primary divisions of the class, of which he characterized four. The fish of his Cycloid order have scales composed of concentric layers of horn or bone, without spinous margins, and not covered by enamel. He believed that a close relationship existed between the absence of pungent teeth on the scales, and the want of spinous rays in the fins, and that this order has a considerable correspondence with the Malacoptygii of former ichthyologists. The Cyclo-Labridae, however, and many Gobiidae, are exceptions to this correspondence, and others exist.

Most commonly the Cycloid scales are imbricated; occasionally they are placed side by side, in contact but not overlapping; sometimes they are more remote; and in Anguilla, the narrow, oblong cycloid scales are in groups lying at right angles to each other, so as to produce a kind of lattice-work under the cuticle. Some genera of fishes with smooth scaleless skins come into this order. The Ctenoid order of fish have horny or unenamelled bony scales, with spinous teeth on the posterior edges of the layers like a comb (figs. 27, 28, 29, and 31). As the scales grow their spinules wear off, and in some species we observe no more than a single series on the posterior edge of the last formed layer of the scales (fig. 28); in others the teeth are more persistent, though the earliest, which are the nearest to the centre of the disk, are generally the smallest. There are some scaleless groups associated with Ctenoids. Scales of this and the preceding order have most commonly grooves radiating from the centre of the disk over that part which remains in the cuticular pouch, and crenatures on the basal edge corresponding with the number of grooves. In both orders, also, the most common circumscriptio of the scale is circular or subcircular; occasionally they are irregular or oblique; and the scales in one part of the fish differ from those in another, in outline, and more frequently in size. In some Labroids the largest scales are on the base of the caudal fin, but in most of the osseous fishes the largest lie towards the middle of the sides of the body. The Ctenoid scales are mostly imbricated. In Ganoid fishes the plates or scales are covered by a thick coat of enamel, and are sometimes of considerable dimensions; and in many of the extinct species which compose the bulk of this order the enamelled plate is rhomboidal, with a hook at its anterior angle, which assists in retaining it in its place. The recent species included by Agassiz in this order do not form a natural group.

Fishes of the Placoid order have the skin covered with irregular plates of hard bone, varying greatly in shape and size. In the Rays and Monk fish they form large, rough, or spinous tubercles; and in the Dog-fish, fine-grained shagreen. As formed by Agassiz, the order corresponds with the Cartilaginei or Chondropterygii of authors, and includes species with smooth skins. For the arrangement of fossil fish these divisions were well devised, but, as may be expected, a system based on the variable characters of a portion of the dermal skeleton fails in defining natural groups. Used in conjunction, however, with the other parts of the structure, Agassiz's discoveries are of great importance for the purpose of classification.

Along the side of an osseous fish, there is a line running from the head to the caudal fin, or even through the latter, called the lateral line. It is nearer the back in some fishes than in others; very generally it runs at mid-height, sometimes it ceases a long way before the caudal fin; and in Chirus there are several lateral lines, the upper one coasting the back, and the lower one the edge of the belly. This line is mucilaceous, being connected with a series of glands. In the Anguillae, the mucous ossicles lying like the scales under the cuticle are scarcely visible, and in many scaleless verniform apodals the line is still less conspicuous; but in these slimy fishes the whole skin is densely studded with glands and their ducts. The scales that cover this line, or lie in immediate contact with it, above and below, are constructed with a tubular arch along their middle, or a simple perforation in the disk, or with a mere notch on the edge for the exit of the mucoduct (figs. 25, 29, 32, 38, 39, 40, 41, 43, and 44). The scales are sometimes larger than the ordinary ones in the same fish, occasionally they are smaller, and sometimes they are the only ones, the rest of the body being naked. frequently they have strange irregular forms (fig. 44), and

they are in some cases peculiarly armed. The lateral line may be traced forwards on the head to one or more little bones named supra-temporals, and thence over the cheek along the sub-orbital series of bones to the first and usually largest of the series, named the pre-orbital, as may be well observed in fig. 8, page 207. All these bones are constructed so as to protect the muciferous canals, and in many fishes they are mere osseous pipes. In the Gadidae and in Macronus, the pre-orbital and following bones of the chain are largely developed and fold down, forming large semi-canals. These bones are strongly armed in some Acanthopteri, particularly the Sclerogenidae, in which the second of the sub-orbital chain emits a spine or series of spines or tubercles, and is prolonged to articulate with the pre-opercular. The marginal serratures of the pre-orbital are conspicuous in Mugil, and furnish characters for other genera of Acanthopteri. The supra-orbitals, though less constant than the sub-orbitals, belong to the same system. The Carp has one above each orbit, and the Lepidosteus three. The turbinals are also considered by Professor Owen to appertain to the dermal system. They are wanting, together with the sub-orbitals, in many of the serpentiniform apodals; but the turbinals exist, though of very small size, in the Conger.

Of the other dermal bones of fishes our notice must be very cursory. The head of the Sturgeon is protected by large dermal plates closely arranged, and the rows continued along the trunk of the fish are, as we have mentioned above, examples of the Placoid scales of Agassiz. The sternum,

of acutely bent dermal bones, and the Dory has two rows of plates along the belly. In the Ostracionidae and Symgnathidae the fish is wholly or completely encased in scales, so connected as to admit of few motions of the body. And in the Gurnards, and many other Sclerogenidae, some genera of Siluridae, the great Sudis among the Clupeidae, and Polypterus among the Ganoids, the cranial and humeral bones of the endo-skeleton present hard, rough, shagreened surfaces exteriorly, in which the soft epidermis is not perceptible, and the resemblance to the dermal plates of the Sturgeon is close. In many other fishes, also, the cranial bones emit processes from their outer surfaces, which serve as canals for the mucoducts.

SECTION IV.—THE MUSCLES AND MUSCULAR MOTIONS OF FISHES.

The spinal column, composed of numerous articulations united by cartilages which permit of certain movements, curves with great facility from side to side; but the vertical motion is much more restricted, chiefly in consequence of the projection of the upper and under spinous processes of the vertebrae.

The great organ of movement in all fishes is the tail. The muscles by which it is brought into play extend in lengthened masses on either side of the vertebral column. The body being rendered specifically lighter by the distention of the swim-bladder when that exists, is impelled forwards by the rapid flexure of the tail acting laterally upon the water. The head of fishes exercises but slight movement, independent of the rest of the body; but the tympano-mandibular arch, often the maxillary and pre-maxillaries, the hyoid and branchial apparatus, and occasionally the scapular arch, have more or less motion. The finny terminations of the last named appendage and of the pelvic bones, as well as the vertical fins, are seldom at rest.

SECTION V.—THE NERVOUS SYSTEM AND SENSES OF FISHES.

The spinal chord, which terminates anteriorly in an enlargement named the brain, consists of a dorsal and ventral pair of columns, the former having for its function the receiving of impressions made on the peripheral surfaces of the body by external objects, and the latter, that of directing the voluntary muscular movements,—they are the nervous centres of animal life. Each consists of an intimate aggregation of nerve matter named ganglia. From the sensorial and motor columns on each side of the chord, nervous filaments, more or less in number, proceed, and being invested by a common membrane, pass out between the vertebrae to all parts of the body; one on each side between every pair of vertebrae, the number of vertebrae being in fact regulated primarily by the number of pairs of spinal nerves. It would be correct to say that the nerves of motion arise from the motor column, and that the nerves of sensation terminate in the sensorial one. For, though the trunks of the nerves lie in a common envelope, the distribution of the former may be compared to a tree having one or more roots, with a trunk giving origin to numerous branches, and innumerable twigs; while the sensorial nerves are like streams formed by minute rills, uniting in a river that terminates by one or several mouths. To serve the involuntary muscles, as the heart and arterial system, and also to supply the viscera that perform the functions of digestion, assimilation, secretion, or to preside over organic life there is a separate system of ganglia and network of nerves that has been named the sympathetic. Under this general description the nervous systems of all the vertebrals may be comprehended; but in the higher classes, the development is much more full than in fishes, and among fishes the Lancelet offers the simplest nervous system of the whole series of vertebrated animals.

The spinal chord, or the nervous columns, for which, independent of its protecting investments, the term myelon has been well devised by Professor Owen, is extremely short in those fishes whose lumpish shape originates in the abbreviation and coalescence of the posterior vertebrae. In Orthagoriscus and Lampris, the whole myelon appears to be a minute ganglionic process of the brain. In Tetrodon and Diodon it is also very short, or about a twentieth of the length of the fish; but the rest of the neural canal is in them occupied by a bundle of caudal nerves, usually named, from their resemblance to the tail of a horse, cauda equina. Lophius has a myelon which reaches the twelfth vertebra; but its pointed end is concealed by a long cauda equina. In most fishes there is no cauda equina, and the myelon runs to the end of the neural canal.

In fishes the brain consists of a few ganglionic masses, which vary in number in different groups of species, and, as has been mentioned, are wholly wanting in the lowest form of the class. It is proportionally larger in the young fish, and Professor Owen states that, on an average, its weight is only a three-thousandth part of that of the whole fish. Carus estimated the brain of the Burbot (Lota) as forming the seven hundred and twentieth part of the entire weight; and that of the Pike has been found to be the thirteen hundred and fifth part.

We mean to mention only the more constant or important encephalic masses, and even these in a very cursory way. The myelon, on expanding into the brain, assumes the name of "epencephalon," which is protected by the occipital neural arch of the skull. In proceeding from the spinal column onwards towards the nose, the first rounded masses that we observe in the epencephalon are not constantly present in fishes, nor do they exist in any other class of vertebrates. They are called "vagal lobes," and are largely developed in the Cyprinidae, and enormously in the Torpedo, Narcine, and other electric Rays. In these they supply the large electric nerves. They are also large in Gymnotus, which, however, does not receive its electric nerves from these organs. The medulla oblongata, and cerebellum, are more constant parts of the occipital division of the brain. Fishes that possess much muscular energy, and take their prey by the velocity of their movements, have the largest cerebellum; and the other extreme of its size is found in the feeble Myxine or Glutinous Hag which passes its parasitic existence buried in the flesh of other fishes. It is also a mere fold in Polypterus, and is very small in the sedentary Discoboli, whose ventral fins are employed as suckers to attach the fish to the rocks. Among osseous fishes the cerebellum attains the largest size in the warmer-blooded, impetuous Tunny; and in the cartilaginous Sharks it is still more largely developed.

The next division of the brain, the "mesencephalon," protected by the neural arch of the parietal vertebra, is usually larger than the other divisions in osseous fishes. To it belong the two optic lobes, whose function is denoted by their name. They are hollow in most fishes, and are often larger than the cerebellum, as in Polypterus and Lepidostiren, of equal size with that organ in Eels, and smaller in the Sharks and in Amblyopsis. Their existence at all in this fish, which is blind, and in the Myxine, which is equally destitute of sight, shows that they have some other function than merely communicating with the optic nerves. The "proencephalon," inclosed in the neural arch of the frontal vertebra, corresponds to the cerebral hemispheres of the higher vertebrals. It is smallest in the Myxines, equal to the cerebellum in the Perch, and exceeds in size that of the Stickleback, Gurnard, Lepidotestes, Lucioperca, Amblyopsis, and Raia. In Polypterus and Lepidostiren it surpasses all the rest of the brain.

The fourth and last division of the brain, protected by the nasal neural arch, consists of two lobes, named "rhinencephala" or "olfactory lobes," as they send forwards the nerves that supply the organ of smell.

Organ of Vision.—The position, direction, and dimensions of the eyes of fishes vary greatly. In some they have an upward aspect, and are often very close upon each other; in others they are lateral, and so wide apart as to be even directed slightly downwards. But of all anomalies, one of the most extraordinary which their position presents, is that of the Pleuronectes (such as Turbot, Flounders, Soles, &c.), in which the two eyes are placed, as it were, the one above the other, and both upon the same side of the head. In certain species of the Eels and Siluri, they are so small as to be scarcely visible; while in other groups, such as Pria- canthus, Pomatomus, and Orthagoriscus, they surpass in proportional diameter whatever is known of the same organs in the higher classes. Some ichthyologists have remarked that fishes which habitually descend to great depths in the ocean have large eyes; and in the internal parasites and in fishes which live in subterranean waters, we have examples of the most rudimentary form of the organ of vision. In the Glutinous Hag, and in the Amblyopsis spelaea, the eye is merely a minute black fold of skin on which a cerebral nerve terminates. In Apterichthys cecus, the eye-ball, still rudimentary, is covered by the skin. It may be said in general that the eye of fishes is large, and that its pupil especially is broad and open; a character probably connected with the necessity of collecting whatever devious rays of light may penetrate the obscure depth of waters. Fishes have no true eyelids. The skin always passes over the eye, to which it is slightly adherent; and it is for the most part sufficiently transparent for the passage of the solar rays. In some species, such as Eels, it passes over without the slightest fold or duplication. In others, as the well-known Mackerel and Herring, it forms an adipose fold both before and behind; but these folds are fixed, and being unprovided with muscles, have no mobility. Sharks have one, somewhat more moveable, on the inferior margin of the orbit. The globe of the eye itself is very slightly moveable, although, like that of man, it is furnished with six muscles. Perhaps the most singular eye presented by the class of fishes is that of Anableps, which has two corneas, separated by an opaque line, and two pupils pierced in the same iris, so that one might deem it double; but there is only one retina, and a single vitreous and crystalline humour.

In Uranoscopus macrops and others of that genus, the eyes can be elevated and depressed at the will of the fish, on a cylindrical stem, above or below the plane of the flat dorsal aspect of the head on which it is situated; and in the ferocious Zygaena, the eyes are tilted out from the sides of the head on cartilaginous expansions of the skull. Fishes, in the range of their vision and acuteness of sight, are very far inferior to birds, and inferior generally to reptiles and beasts, yet, at the same time, it is evident that they perceive their prey from a considerable distance; and the angler, who knows either how rapidly they seize, or how cautiously they avoid his lure, and with what discrimination they sometimes prefer one colour or kind of artificial fly to another, must be impressed with the belief that the vision, at least of certain species, is by no means devoid of clearness and precision.

We shall not repeat here the notices that we have already had occasion to take of the organ of hearing. In Sharks, a canal extends from the interior organ of hearing to the hinder part of the head, where it is closed by the skin, and in the rays there is a very minute external orifice to the canal, closely approximated on the dorsal aspect of the head to its fellow. In osseous fishes there is no such mechanism, and the sonorous vibrations are conveyed to the labyrinth through the solid parts; but in the Carp and certain Siluroids, the air-bladder would appear to be accessory to the acoustic organ, as it is connected with it by a chain of ossicles. The general structure of the organ of hearing in fishes is doubtless specially adapted for the sensation of the sonorous undulations of the element in which they live.

A few lines may now be devoted to the consideration of the sense of smell. The nostrils of fishes are not so placed as to be traversed by the respiratory medium in its course to the organs of respiration. They consist merely of two openings, situate on the muzzle, and lined by the pituitary membrane, which is raised in extremely regular folds. Their shape is sometimes oblong, sometimes round or oval. They are placed either at the end of the muzzle or on its sides; sometimes on its superior face, and even occasionally, as in Skates (fig. 48), and Sharks, on its under surface near the angle of the mouth. In the Lamprey they are approximate on the top of the head, and open by one common orifice (fig. 49). In the great majority of fishes each nostril opens by two orifices, the one posterior to the other, and in some cases at a considerable distance. These are what are called double nostrils, an inaccurate term, in as far as each pair of holes leads only to a single cavity. The margins of the anterior orifice are often tubular, as in the Eel, and sometimes a single side of the tubular margin is prolonged into a tentacular appendage, as in several Siluri. In the genus Lophius the nostrils are borne upon a little pedicle, so as somewhat to resemble mushrooms. Various other modifications are observable in different genera, although not necessary to be here narrated.

It is certain that fishes possess the faculty of perceiving odours; that various scents attract or repel them; and there is no reason to doubt that the seat of that perception lies in the nostrils. It may be reasonably conjectured that its strength depends mainly on the degree of development produced by the number and extent of the interior folds of the pituitary membrane.

The essential character of the organ of smell in fishes is that the pituitary sac has one or more external openings not communicating with the mouth or fauces except in the Dermopteridae, and in these the naso-palatine canal is not traversed by the water in its course to the gills. In some Synbranchidae, the posterior nasal aperture is situate on the white parts, within the edge of the lip, in this respect agreeing with the Lepidosiren. Long debates on the conflicting claims of the latter to be ranked as a fish or a reptile, have turned on the position of the posterior nostril. Tetrodon noratus is an exception to the general rule of double nostrils, in having merely a single wide opening, coextensive with the dimensions of the pituitary sac, but bordered by membrane. In other Tetrodons the sac is closed by a thin membrane, in which there are two small openings close to each other. The Chromisidae also, and the Ctenoid Labridae, have but one opening to each sac; and in some few fishes there is a barbel merely, without an aperture, in place of a nostril.

In regard to the sense of taste in fishes, it is evident that as, with few exceptions, they swallow their food rapidly and without mastication, their perception of that faculty must be in noways acute. The same may be inferred from the fact of their tongue being almost immovable, often entirely osseous, or beset with teeth or dental plates, and from its receiving very slender nerves, and these but few in number. Even those species of which the jaws are so armed as to enable them to cut and bruise their aliment, cannot long retain the latter in their mouths, on account of the position and the play of the respiratory organs. No salivary glands discharge their moisture on the organs of taste. The tongue itself is not seldom entirely wanting; and even when it exists in its most distinct and apparently fleshy state, it consists merely of a ligamentous or cellular substance, applied on the surface of the lingual bone. It is never furnished with muscles capable of producing any movement of extension or retraction, as in quadrupeds.

Fishes cannot be said to be more highly favoured in respect to the organs of touch than those of taste. The faculty is greatly deadened over the general surface by the coating of scales, and in the particular members by the inflexibility of the rays. It is chiefly confined to the lips, and even these parts in many species are themselves as hard and insensible as bone. Certain soft and delicate appendages called barbels, possessed by many species, such as the Cod and Loach, are supposed to enjoy a more delicate perception of the sense of touch; and among the Selvogonidae there are many species that have one or more rays of the pectoral detached from the membrane, so as to become truly delicate, flexible fingers, not for prehension but for touch. The common Gurnard has been seen in a clear sea swimming along near a sandy bottom, and exploring it with these special organs of touch. It is by means of the dermis that that peculiar matter, so remarkable for its silvery metallic lustre, and which bestows so much of brilliancy upon the class, is secreted beneath the scales. It is composed of small polished plates resembling burnished silver, and capable of being removed by washing, either from the skin itself, or from the inferior surface of the scales. It is this substance that is used in the formation of false pearls. It is also secreted by many species in the thickness of the peritoneum, and in the envelopes supplied by that part to particular viscera, especially the swimming bladder.

It thus appears that the external senses of fishes convey to them few lively or distinct impressions; and by whatever scenes in nature they are surrounded, their perceptions are probably indistinct and dull. Their sexual emotions, cold as their blood, indicate only individual wants. Few species pair, or enjoy any connubial gratification, for the males seek the eggs rather than the females which deposit them, and neither sex ever recognises its offspring. At least the exceptions to these general laws are extremely few, and when they occur they are of the lowest animal description. A pair of Congers are so deaf to external impressions at the time of sexual congress, and so automatically, as it were, engaged, that they have been taken by the hand together out of the water. Sharks and gay creatures of the sky have the power of surveying distinctly at a glance an immeasurable extent of horizon; their acute perception of hearing appreciates all sounds, and every intonation; and their glad voices are exquisitely skilled in their production. Though their bills be hard, and their bodies covered by down and feathers, they are by no means deficient in the sense of touch. They enjoy all the delights of conjugal and parental affection, and perform their incumbent duties with devotedness and courage; they cherish and defend their offspring, and will sometimes die in their defence; and of all the wonderful labours of instinctive art, none is so beautiful as the formation of their mossy dwellings. With what deep and continuous affection does the female brood over her cherished treasures! how unwearied is the gallant male in his tender assiduities, and in the rich outpouring of that varied song by which he seeks to soothe her sedentary task! The same principle of attachment and discrimination is even made available in a state of domestication by the skill of all-engrossing man. A bird acquires a knowledge of its master, and submits to and obeys that master's will; and the proud falcon, which in its natural state

"Both daily with the wind, and scorn the sun,"

will wheel in airy circles over a well-trained dog, or stoop its boldest flight at some familiar urchin's call. Other species will even imitate man's noblest faculty, the power of speech,—and it is thus with somewhat doubtful feelings that we deny to them the gift of reason.

But the silent dweller in the deep knows few attachments, expresses no language, cherishes no affections. Constructing no dwelling, he merely shelters himself from danger among the cavernous rocks of the ocean, or beneath the murky shade of the overhanging banks of rivers; and the cravings of hunger seem alone to exercise a frequent or influential action over his monotonous movements. We must not, however, suppose that the life of fishes is not one of enjoyment, for we know that the great Creator "careth for all his creatures;" and it ought perhaps rather to be said that we cannot appreciate the nature of their feelings, than that they are in any way fore-doomed to a negation of pleasure. Assuredly, however, the hand of nature has been most prodigal in bestowing on their external aspect every variety of adornment. Their special forms are infinite, their proportions often most elegant, their colours lively and diversified, and nothing seems wanting in them to excite the admiration of mankind. Indeed it almost appears as if this prodigality of beauty was intended solely for such an end. The brightness of metallic splendour, the sparkling brilliancy of precious gems, the milder effulgence of the hues of flowers, all combine to signalize fishes as among the most beautiful objects of creation. When newly withdrawn from their native element, or still gliding submerged in its liquid coolness, their colours, fixed or iridescent, are seen mingling in streaks or bands, or broader flashes, always elegant and symmetrical; sometimes richly contrasted, sometimes gradually softened into each other; and in all cases harmonizing with a chaste fulness of effect, which Titian or Rubens might envy, but could never equal. For what reason, then, it has been asked, has all this adornment been so lavishly bestowed on creatures which can scarcely perceive each other amid the dim and perpetual twilight of the deep? Shakspeare has already said that there are "more things in heaven and earth than are dreamt of in our philosophy;" and we fear it is no answer to the foregoing question to add, that the same observation applies with even greater truth to the "waters beneath the earth."

SECTION VI.—THE NUTRITION, MANDUCATION, AND DEGLUTITION OF FISHES.

The nutritive functions of fishes follow the same order. of progression as those of the other vertebrate classes; they seize, and some divide, their food with their teeth; they digest it in the stomach, from whence it passes into the intestinal canal, where it receives a supply of bile from the liver, and frequently a liquid similar to that of the pancreas; the nutritive juices, absorbed by vessels analogous to lacteals, and probably taken up in part also directly by the veins, are mingled with the venous blood which is flowing towards the heart, from whence it is pushed to the branchiae, in which, coming into contact with the water, it is converted into arterial blood, and then proceeds to the nourishment of the whole body. As in other animals, also, certain properties are carried off from the blood by transpiration, the secreting power of the kidneys, &c.

Fishes in general are extremely voracious, and the rule of "eat or be eaten" applies to them with unusual force. They are almost constantly engaged in the pursuit and capture of their prey; their degree of power in these respects depending of course on the dimensions of the mouth and throat, and the strength of the teeth and jaws. If the teeth are sharp and hooked, they are capable of securing the slenderest and most agile animals; if they are broad and strong, they are able to bruise the hardest aliment; if they are feeble or entirely wanting, they are only serviceable in procuring some inert or unresisting prey. Fishes indeed show but little choice in the selection of their food, and their digestive powers are so strong and rapid as to suffice to dissolve very speedily all kinds of animal substances. They greedily swallow other fishes, notwithstanding the sharp spines or bony ridges with which they may be armed; they attack and devour crabs and shell-fish, gulping them entire if they cannot otherwise attain their object; they do not object occasionally to swallow the young even of their own species, and the more powerful kinds carry their warfare into other kingdoms of nature, and revel on rats, reptiles, and young ducklings, to say nothing of the ferocious Shark, which not seldom makes a meal even of the lord of the creation. The species which live chiefly on vegetable substances are few in number.

The growth of fishes depends greatly on the nature and supply of food, and different individuals of the same species exhibit a great disparity in their respective dimensions. They grow less rapidly in small ponds or shallow streams, than in large lakes and deep rivers. The growth itself seems to continue for a great length of time, and we can scarcely set bounds to, certainly we know not with precision, the utmost range of the specific size of fishes. Even among species in no way remarkable for their dimensions, we ever and anon meet with ancient individuals, favourably situated, which vastly exceed the ordinary weight and measurement of their kind.

The teeth of fishes are more variable in form, structure, number, and position, than those of any other class of animals. They are depressed prisms of three, four, five, or six sides in Myloletes, Myliobates or Scarus. More generally they are round and tapering, varying in length and thickness from the "short obtuse cone," to the "long conical," "subulate," "acicular forms," even to such fineness as to be named "ciliiform." Their points may be curved, reflexed, and bent at right angles, and their bases may be fixed or moveable. In some Gobiidae their forms and free motion have caused them to be compared to the keys of a piano. When acicular or ciliiform teeth are arranged so closely as to resemble the pile of velvet, they are said to be "villiform" (en velours); and when coarser and straight, or with their points bent back, they are "card-like," or "cardiform," or they may be rasp-like or carduliform (en röpe ou en cardes). The Cheetodontidae are named from their setiform teeth. In the Sphyraena we have examples of teeth exactly resembling the blade of a surgeon's lancet (vide fig. 19), and in Sharks the teeth have a variety of forms, from the long tridental dagger or spike-nail of Oxyrhina and Odontaspis, to the serrated or lobed cutting teeth of Galeocerdo, Carcharodon, Carcharias, and other genera, set in a row so as to make a most powerful instrument, by which one of these creatures is able to divide a man's body into two at a single bite, down to the pavement-like or tessellated teeth (en pavés) of the Dog-fish, or Cetorrhinus, used for crushing. The Carp has a crushing apparatus at the entrance of the gullet. In Myliobates, Aetobates, Rhinoptera, the pavement formed by the broad teeth is of the most regular and beautiful kind. In Scarus and Hoplognathus or Scarodon, the teeth are so united to the premaxillaries and mandible as to form but a single tooth in each jaw, while in Calliodon, the union of the teeth

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1 The writer of this treatise kept a minnow little more than half an inch long in a glass tumbler for a period of two years, during which time there was no perceptible increase in its dimensions. Had it continued in its native stream, subjected to the fattening influence of a continuous flow of water, and a consequent increase in the quantity and variety of its natural food, its cubic dimensions would probably have been twenty times greater; yet it must have attained, prior to the lapse of a couple of years, to the usual period of the adult state. (J. W.) with the bone is less complete, and their edges rise above the general surface.

In *Diodon*, we have the same kind of single tooth in each jaw, or rather confluence of teeth and jaw. In *Tetradon*, the dentiferous jaws are divided by a mesial suture so as to present two compound teeth above and as many below.

In the *Plagiostomes*, the teeth are limited to the maxillary and mandibular bones, while in the genus *Cyprinus* teeth are wanting in the jaws, but, as mentioned above, these fish have grinding teeth on the pharyngeals and basioccipital. In the *Catastomini* of the Cyprinoid family, the pharyngeal teeth are arranged on a crescentic bone like the teeth of a curved comb, the points being thickened for grinding. In *Scarus*, besides the solidly aggregated jaw-

teeth above mentioned, there are also pharyngeal grinders.

In *Crenidens*, thin tricuspid teeth placed in many close rows on the jaws, serve to cut the tender fuci on which these fishes feed. In passing through the whole series of fishes, we find teeth on the nasal bone, as in *Muraena*, where they stand in a row round the edge of the bone, and in one down the longitudinal mesial line; on the pre-maxillary, the maxillary, the palatines, the vomer, the hyoid-bones, the branchial arches, and especially on their processes, named "rakers." Teeth occur on the maxillary only when it enters into the composition of the orifice of the mouth, as in the *Clupeidae* and *Salmonidae*. In *Pristis*, of the Ray tribe, the flat snout, greatly prolonged, and well ossified, is set on each side by a series of very strong nail-shaped teeth, whence its name of Saw-fish among sailors, though it is in reality a weapon that wounds by repeated blows, not by cutting longitudinally like a saw. This snout forms a dangerous sword in the hands of the Polynesians who use it as such. The Lampreys have rows of teeth on the lips, as

well as strong pharyngeals. Commonly the teeth do not cross the symphysis of the jaw, there being in most cases a line of division between the pre-maxillaries or at the union of the limbs of the mandible. Instances to the contrary have already been mentioned in *Scarus*, *Hoplognathus*, and *Diodon*. In *Notidanus*, *Seymus*, and *Myliobates*, among the Plagiostomi, we have also examples of this departure from the dental type of the higher animals. In the majority of osseous fishes, besides the lips, which, having no peculiar muscles, can exert but little strength in retaining the aliment, there is generally in the inside of each jaw, behind the anterior teeth, a kind of membranous fold or valve, formed by a replication of the interior skin, and directed backwards, of which the effect is to hinder the alimentary substances, and especially the water gulped during respiration, from escaping again by the mouth. This structure does not, as formerly supposed, constitute a character restricted to the genus Zeus, but exists in an infinity of fishes. The food seized by the teeth of the jaws, and detained by the valve just mentioned, is carried still farther back by the teeth of the palate and tongue when these exist, and is at the same time prevented by the rakers of the branchial arches from penetrating between the intervals of the branchial, where it might injure the delicate organs of respiration. The movements of the jaws and tongue can thus send the food only in the direction of the pharynx, where it undergoes additional action on the part of the teeth of the pharyngeal bones, which triturate or carry it backwards into the oesophagus. The last-named part is clothed by a layer of strong, close-set, muscular fibres, sometimes forming various bundles, the contractions of which push the alimentary matter into the stomach, thus completing the act of deglutition.

SECTION VII.—THE CIRCULATION OF FISHES.

Fishes, in common with warm-blooded animals, are provided with a complete circulation for the body, and with another equally complete for the organs of respiration, and with a particular abdominal circulation terminating at the liver by means of the vena portae; but their peculiar character consists in this, that the branchial circulation alone is provided at its base with a muscular apparatus or heart, corresponding to the right auricle and ventricle of the higher classes, while nothing of the kind exists at the base of the circulating system of the body; in other words, the left auricle and ventricle are entirely wanting—the branchial veins changing into arteries without any muscular envelope.

The muscular apparatus of their circulation is composed of the auricle, the ventricle, and the bulb of the pulmonary artery, and the auricle itself is preceded by a large sinus, in which all the veins of the body terminate; thus there are in a single series four cavities separated by constrictions, into which the blood must flow in its progress from the body to the branchiae. Their size is small in proportion to the dimensions of the body, and does not increase in the same ratio with the growth of the individual. Three of these receptacles, the auricle, the heart, and the bulb, are lodged in a pericardium, which is itself placed beneath the pharyngeal bones, between the inferior parts of the branchial arches, and for the most part protected, externally by the scapular arch. Except in the Plagiostomes, the great venous sinus is not placed in the pericardium, but between the posterior partition of that cavity and the membrane which represents the diaphragm, and which is merely the anterior portion of the peritoneum strengthened by aponeurotic fibres. This sinus is extended transversely, and receives by several different trunks the veins of the liver, of the generative organs, of the kidneys, of the fins, branchia, and throat; and finally those of the head, which themselves partly pass by a sinus at the back of the cranium. The first-mentioned sinus sends the whole of this blood by a single orifice of its anterior convexity into the auricle, which receives it through the opening of its anterior portion. Two thin membranous valvules protect this communication, and are turned towards the auricle. The latter organ is placed in the pericardium, in front of the great sinus, and above the ventricle, that is, on its dorsal aspect. The ventricle presents very various and often remarkable configurations. In osseous fishes it is usually of a tetrahedral form,—in the cartilaginous kinds more frequently rounded and depressed. It is situate beneath the auricle, the cavity being so turned as to be almost vertical next that organ, and horizontal towards the bulb. Its coats are extremely robust, and furnished internally with powerful fleshy columns, its substance being composed of two different layers. But it is in the bulb of the branchial artery that we find the most vigorous fibres, usually disposed in a circular form. The prolongation of this bulb issues from the pericardium, and becomes the branchial artery, advancing forward beneath the single chain of small bones which unites the arches of the branchia. The branchial artery soon divides, and in such a manner as to send a branch to each branchia. These branches pass along a hollow groove on the convexity of each branchial arch, and more external than the vein which follows the same track, but in an opposite direction. To the arch are attached a great number of leaflets, parallel to each other, usually terminated in a forked point, and sometimes deeply divided. The principal branch which passes along the groove of the arch gives a smaller branch to each of the leaflets; and this branch, after being twice bifurcated, furnishes an infinity of lesser branchlets, which meander over the surface of each leaflet, till they finally terminate in extremely minute veins. These little vessels meet on each side in a branchial vein, which proceeds along the internal margin of the lateral lobe of the leaflet, and the two veins open into the trunk of the great vein of the branchia.

On passing out of the dorsal side of the branchia, the branchial veins assume the structure and functions of arteries; even before their arrival at this point, the anterior have already sent several branches to different portions of the head; and it is necessary to remark, that the heart and several parts situate in the chest receive their blood from a branchial vein, by means of an offset issuing from near its source, and consequently anterior to its exit from the branchia. Nevertheless, it is only by the re-union of the

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1 The various notices (as already intimated) of the internal structure of fishes contained in the article COMPARATIVE ANATOMY of this work (vol. III.) absolve us from the necessity of presenting any details regarding the form and constitution of the intestinal canal, and of certain other important interior organs of the class. The forms of the stomach, whether "spinal" or "coecal," the pancreatic apparatus passing from slender coelial appendages to the intestinal canal, which secrete a proper fluid but do not admit the food, gradually increasing in complexity to the pancreatic conglomerate gland of the sturgeon, are parts of structure which the ichthyologist is required always to pay attention to; and also to the extension of the inner coats of the intestine by valvular folds, producing a more extensive secreting surface, and delaying the passage of the food. The two forms of spiral valves in the lower gut of sharks, and in some of the osseous apodals, require special notice. trunks proceeding from the four branchiae that the great artery is formed which carries the blood to the viscera and all the parts of the trunk, and which is by consequence the representative of the sorta of the Mammalia—but of an aorta which possesses neither auricle nor ventricle at its base. Thus, according to Cuvier's views, the left cavities of the heart of quadrupeds do not exist in fishes, but are replaced by a simple vascular apparatus, situate above the branchiae, in like manner as the right cavities are placed beneath them.

SECTION VIII.—THE RESPIRATION OF FISHES.

It is by an almost infinite subdivision of the vessels over the surface of the branchiae or gills, that the blood of fishes becomes subjected to the influence of the circumambient water, which is made to flow incessantly between the branchiae by the movement of the jaws, and of the opercular and hyoidian apparatus. This mode of respiration is as necessary to fishes as the direct respiration of air is to other animals. If the air is expelled by ebullition from the water, fishes cannot live; and many species are obliged to rise frequently to the surface for the purpose of breathing atmospheric air. It is easy to suffocate various kinds, by keeping them beneath the surface, inclosed in a gauze net. The absorption of oxygen, however, is comparatively small among these aquatics, for it has been calculated that a man consumes fifty thousand times more than is required by a Tench. When fishes are deprived of water, they perish not so much for want of oxygen, as because their branchiae become dry, and unable to perform their functions duly. Hence the species of which the branchial orifice is small, as the Eel, or those which possess receptacles for moisture, like Anabas and Ophicephalus, long survive exposure; while such as have their gills greatly cleft and open, as the Herring, expire almost instantly when withdrawn from their moist abode. Some fishes, as Amphipnous eucharis, and Saccobranchus singio, have a pulmoniform sac for supplying air to the gills.

SECTION IX.—THE AIR-BLADDER OF FISHES.

One of the most remarkable and characteristic organs of fishes is the air or swim-bladder. In many genera it has no opening or external communication, and in these the air which it contains must be the result of secretion. It is composed of an extremely fine internal tunic, of another of a thicker texture and peculiar fibrous structure, remarkable for producing the finest kind of isinglass, and is inclosed within the general coating with which the peritoneum invests the other viscera. It is sometimes simple, as in Perch, sometimes furnished with more or less numerous appendages, as in some of the Haddock tribe, or branched, as in certain Sciaenae. Occasionally we find it divided, as it were, into two or more parts, by a constriction, as in the genus Cyprinus, many of the Siluride, and others. It is chiefly among the abdominal fishes that we find it communicating by a tube with the intestinal canal, and either directly with the oesophagus, as in Cyprinus, or with the base of the stomach, as in the Herring. That of the Sturgeon opens into the former portion by means of a large orifice. Professor Owen states generally that the contents of the air-bladder consist in most fresh-water fishes of nitrogen, with a very small quantity of oxygen and a trace of carbonic acid; but that in the air-bladder of sea-fishes living at great depths, oxygen predominates. Biot found as much as 87 per cent. of oxygen in the air-bladder of deep-sea Mediterranean fishes. Dr Davy in the air-bladder of fresh-run Salmon found a trace of carbonic acid, and 10 per cent. of oxygen, the remainder of the air being nitrogen. Humboldt found 4 per cent. oxygen, and 96 per cent. nitrogen, in the air-bladder of Gymnotus. That the air-bladder is homologous with the lungs of the higher animals, is the opinion of the best physiologist of the present day. These in their embryo state have gills, the lungs being developed when needed. In fishes the gills are persistent, while the air-bladder is simple and embryonic, having chiefly a mechanical function to perform. In the Salmandroid Ganoidi, however, various Siluroidei, and Prototetra, the air-bladder shows some pulmoniform complications. The Lepidosiren of the Gambia remains buried in the mud during the dry season, and its respiration is performed by pulmonary air-bladders, which have short, wide tracheæ, kept open by cartilaginous orifices; and all the oxygenation of the blood required during the torpid condition of the fish is effected in the blood-vessels ramified over the air-bladders.

The more obvious use of this organ seems to be to maintain the fish in equilibrium, or to lighten or increase its relative weight, so as to cause an ascension or a sinking, in proportion as the bladder is compressed or expanded. This is probably effected by the contraction or dilatation of the ribs. At all events it is certain, that when the air-bladder bursts, the fish remains at the bottom, usually turning up its belly, and exhibiting other irregularities in its locomotion. Another curious effect is observable in regard to fishes which have been suddenly brought from a great depth by means of a long fishing line, and which having no time either to compress or partially empty the organ in question, the air which it contains being no longer pressed by the heavy weight of water, either expands so as to burst the bladder, or by its dilation forces the stomach and oesophagus into the fish's mouth. When the air-bladder is pierced artificially, the fish almost immediately turns upon its back, and sinks to the bottom.

Though of the highest importance in the structure of such species as possess it (and these are by far the greater number), yet the air-bladder is not indispensable in the general economy of the class of fishes. In some fishes it is no bigger than a pea; in several genera (e.g., Pleuronectes) it is entirely wanting, and the species in such cases generally remain at the bottom, and, swimming obliquely on one side, propel themselves forward by a nearly vertical motion of the tail. In such cases both eyes are on the same side, and the whole structure of the fish, especially the skeleton of the head, presents an unsymmetrical aspect of a very extraordinary kind. In many cartilaginous fishes, such as Rays (commonly called Skates), the absence of the swimming bladder seems compensated by the enormous size of the pectoral fins, which, of all the external organs, are probably the most efficient in raising the body, as the caudal extremity is the power chiefly employed during an onward course. The Lamprey, which has neither swimming bladder nor pectoral fins, dwells in the mud. Flat fishes being unprovided with swimming bladders, are supposed for that reason to raise themselves with difficulty to the surface; and they do not appear to strike the water laterally like other fishes, but swim rather after the manner of the Cetacea, by a motion alternately up and down. In all the other animals of this class the chief organ of progressive motion is the tail, or prolongation of the body, terminated by a caudal fin, the position of which, unlike that of the great aquatic mammalia called whales, is vertical. The reason of the difference is obviously this: a true fish, pos-

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1 Transactions of the Royal Society of Edinburgh, xxi., p. 245, 1855. 2 De Aute et Auditu, &c. 3 In several insects of the genus Blatta we have observed a want of symmetry both in the size and markings of the elytra. We do not mean an accidental variation of one side, but an evidently pre-ordained disparity of form and colour.Classification.

sessing the power of extracting air from water by means of its gills, does not (except at rare intervals) require to mount to the surface for the performance of the vital act of respiration; but all cetaceous animals being furnished with lungs, which cannot perform their functions except through an immediate communication with the atmosphere, require their bodies to be terminated by a horizontal expansion, the action of which is the most efficient for an ascending course. It is, however, difficult to account for the fact that so considerable an organ as the swimming-bladder should have been denied to so many species, not only of the more indolent kinds, which dwell composedly at the bottom of the waters, but to many others which yield to none of their class in the ease and velocity of their movements. Its presence or absence does not even accord with the other conditions of organization; for while it is wanting in the common Mackerel, it is found to occur in a closely allied species, the *Scomber pneumatophorus* of Laroche. Weber has pointed out a remarkable connection between the air-bladder and the acoustic organs in the head.

We have already alluded to a singular peculiarity connected with the organization of certain fishes—we mean the power of conveying electrical shocks. In Torpedos, the apparatus consists of two organs, built up of membranous tubes filled with mucous matter, divided by transverse chambers closely set together, like the cells of honeycomb, and disposed in two groups placed on each side of the head. They receive enormous branches of nerves from the fifth and eighth pair. In the *Gymnotus* the electric organs are four, and occupy the under surface of the body throughout its entire extent to a considerable thickness. It is composed of parallel plates separated by thin layers of mucilage. The effect of this natural galvanic pile will be detailed in the course of the systematic portion of this article, when we shall have occasion to mention the electric fishes in their proper place.

CLASSIFICATION OF FISHES.

A "natural arrangement" of fishes or of any other class of animals implies an accurate knowledge of their whole structure, internal as well as external, by which they can be grouped in the order of their affinities, placing those species together which agree with one another in the greatest number of important characters. Naturalists have generally come to the conclusion that the series of species is not a linear one; some have one portion of their frames, some another, specially organized for the part the species has to play in the system of nature; and so the affinities branch off in several directions. The nervous system being that by which an animal has perception of external objects, and directs its motions accordingly, and which presides moreover over those operations of organic life that are not obedient to the will, would be one important basis of classification, but its various modifications of structure in fishes are still too imperfectly known, and the labour and skill necessary for the elucidation and discrimination of its parts and their functions are such that, practically, it has hitherto been as yet but little referred to in the arrangements of the systematic ichthyologist. The same is true in a greater or less degree of the other parts of the organism employed in nutrition, respiration and circulation, secretion, generation, and development; most of the arrangements of fishes that have hitherto appeared being based on the organs of locomotion and the external integument, the latter the most variable certainly that could have been chosen, but at the same time the least important. We have scaly, partially scaly, and scaleless species in the same genus of some particular groups. Agassiz has been labouring assiduously on embryonic development as a basis of arrangement; but as far as we know, has not yet published a system founded on his researches in this direction. All attempts at classification of fishes which have hitherto been given to the world, violate more or less anatomical affinities; the best on the whole that has been proposed, is that of Professor Johannes Müller, which we shall follow, adopting the modifications of Professor Owen. It would be a great help to the memory were the divisions of the class of equal rank to approach to equality also in the number of species that they embrace, but this cannot be; though most probably the disparity in the size of the groups would be considerably lessened were we acquainted with all the species secluded in the depths of the sea, and still unknown, as well as with the forms of the extinct fishes. The *Salamandroid* Ganoids which abounded in variety and number in another epoch of the earth's history, have only a few existing representatives; and of the palaeozoic fishes with soft skins that are less likely to be preserved than the strongly cuirassed Ganoids, we know absolutely nothing, not even that such were then created.

In his arrangement of fishes, Müller finds characters which he considers to be of the highest importance in the vascular system. The heart of fishes is a venous or branchial one, consisting of an auricle in which the veins terminate, and a ventricle for transmitting that venous blood to the gills where it is aerated and whence it circulates through the body without the intervention of a special pumping organ like the systematic side of the heart of a higher animal; but merely through the general contractile power of the arteries. In most fishes there is a thick muscular swelling of the commencement of the arterial system close to the ventricle, and which, in fact, may be called a third chamber of the heart. The blood is prevented from regurgitating into the ventricle on the contraction of the bulb by valves; and the number of these valves, and the presence or absence of the thick muscular coat of the bulb, furnish characters of groups so constant, that Müller says he is acquainted with no others, either anatomical or zoological, which equal them in certainty. The *Plagiostomi*, or cartilaginous fishes, as restricted by the removal of several groups that were included among them by the older ichthyologists, have three or more longitudinal rows of valves within the muscular bulb. A still greater number of valves are present in the bulb of the existing Ganoids; but in the large group formed by the osseous fishes after the Ganoids have been removed from them, two opposite valves are placed at the origin of the bulb, and no more. This great group Müller names *Teleostei*, or perfect osseous fishes; and he includes in it the six following orders mentioned in the subjoined table.—*Acanthopteri*, *Anacanthini*, *Pharyngognathi*, *Physostomi*, *Pleotognathi*, and *Lophobranichi*. The *Cyclostomes* of Cuvier, or the Suckers, want the *bulbus arteriosus*, or thickened muscular tunic, but have two valves at the origin of the branchial vessel like the *Teleostei*; while the Lancelet (*Amphioxus*) wants the heart itself, the circulation being carried on by the muscularity of the entire vascular system. This fish, therefore, he considers as the type of a sub-class which he names *Leptocardii*. Another sub-class, termed *Dipnoi*, includes fishes which have scales, with both lungs and gills. In all, he makes six sub-classes of fish—1. *Teleostei*; 2. *Dipnoi*; 3. *Ganoidei*; 4. *Elasmobranchii*; 5. *Marsipobranchii* or *Cyclostomi*; 6. *Leptocardii*. In the subjoined modification of his arrangement by Professor Owen, these subclasses are not preserved, the class being sub-divided into nine orders, and again into sub-orders. A few changes have been made by us in the termination of the names of CLASS OF FISHES.

ORDER I.—DERMOPTEROUS FISHES.

Sub-Order I.—PHARYNGOBRANCHS.

This order is named from the cutaneous vertical fins, in which the mucoid rays are extremely soft and delicate, or altogether imperceptible, and from the want of pectoral or ventral members. The first two sub-orders are founded on the different developments of the respiratory organs. In the first the pharynx itself is organized for respiration, and two processes having the function of gills project freely into the cavity of the mouth; the water necessary for respiration flowing over them by the same canal which carries the food; there being no lateral gill-openings through the skin. Of this sub-order the best known representative is the *Amphioxus lanceolatus* of Yarrell (*Branchiostoma lubricum*, Costa), which was first made known to the world as a *Limax* or Slug by Pallas, who received it from the Cornish coast. Recently Mr Couch rediscovered it on the same shores, and Mr Yarrell has described it in his excellent work on British Fishes, according to its true affinities as a fish, though its want of a head was puzzling. Its structure has since been investigated by Raitz, Johannes Müller, Owen, Goodrich, Swan, and other first-rate comparative anatomists,—many specimens having been procured among the gravel and rocks of the sea-beaches in the south of England, also in the Irish Channel, on the Norway coast, and in the Mediterranean. The longitudinal slit forming the orifice of its mouth resembles, to the unassisted eye, that of a Lamprey, its jointed labial feelers looking like moveable teeth. It is a thin semi-transparent creature about an inch and a half long, without jaws, but having a large buccal cavity into which the short vascular processes that perform the function of gills project freely, without cartilaginous supports or lateral attachments. The buccal cavity communicates by a small pharyngeal opening with a wide barrel-shaped oesophagus, which occupies more than a fourth of the whole length of the fish, and whose interior surface is ciliated throughout, and organized to assist in respiration. Vessels that ramify over its vertical ciliated bands communicate with the dorsal and ventral portions of the vascular trunk that carries on the circulation, without the intervention of a central propelling organ. There is, however, beneath the posterior end of the expanded oesophagus a small widening of the circumferential vessel which pulsates rhythmically, and which Professor Owen considers to be a rudimental representation of the branchial heart of the Myxinoidea, the next order of fishes in point of organization. The peculiarity of shape which distinguishes the Lancelet from all other fishes, arises from all its nerves of the senses devolving from the myelon or spinal marrow, without the production of a ganglionic brain, and consequently, without the necessary expansion of the protecting integuments which make the head, and in animals more advanced in the scale, provide sockets for the sense capsules. The only cartilaginous part of this fish is a jointed lamelliform arch which extends from the anterior end of the spinal chord on the ventral aspect to the orifice of the pharynx, and serves to support the oral filaments. It represents the labial arch of the higher Myxinoidea. Though this little creature wants jaws, it has, as we have just mentioned, a large buccal cavity which, as in other fishes, admits not only food, but also aerated water, to the respiratory organs, and an enormous oesophagus having the double function of deglutition and respiration. The intestine proceeding from the oesophageal bag is slender, almost straight, and terminates at the anus, about one-fourth of the whole length of the fish from the point of its tail. In its motions, the Lancelet is lively and active, and shelters itself quickly from observation among the gravel. In 1853 Sundevall distinguished two American species of *Amphioxus* or *Branchiostoma*, the *B. caribaeum* from the West Indies, and *elongatum* from Peru; but Professor Peters on comparing the species found that *caribaeum* was identical with the European one. Dr Gray has described a Borneo specimen as a distinct species, so that the genus probably is not so poor in species as was at first supposed.

CLASS.—PISCES.

ORDER I.—DERMOPTERI.

Vermiform, branchial and apodous; endo-skeleton unossified; exoskeleton and vertical fins muco-dermoid; no pancreas; non-air-bladder. The development of the skull in the Dermopterous fishes is arrested at more or less embryonic stages, but in each genus it proceeds in a specific direction; thus, in the Lancelet, evolving an articulated labial arch and its numerous filaments; and in the Myxinoidea and Lampreys forming a more complex system of lateral labial cartilages; or modifying the palatine, maxillary, and hyoid rudiments in relation to the euctorial function of the mouth. The olfactory organ, which is double in all other fishes, is single in this order; and the eye is rudimentary, being merely a small fold of skin coated with a speck of dark pigment. It is probable that this point is sensitive to light, as the lowest member of the order, the Lancelet, quickly excludes itself among gravel when exposed to light. In *Ammocoetes* and the Myxinoidea the cartilaginous capsules of the acoustic organs retain the embryonic position of projecting spheres at the base of the cranium; these are less prominent in the Lampreys. In the teleostei they are embedded in the walls of the cartilaginous skull, and in the bony fishes they are usually covered by ossification. The oral filaments and soft integuments of the anterior end of the Lancelet and Myxines receive many nervous twigs from the fifth pair; and touch seems to be the most important sense in these low vertebrates.

Sub-Order I.—PHARYNGOBRANCHII.

*Cirrhosoma*, allorhyn. Gills free, pharyngeal; no heart. A single genus of few species.

Family I.—AMPHIOXIDÆ.

Genus I. *Amphioxus*, Yarrell. (*Branchiostoma*, Owen.) Respiratory processes projecting from above the pharynx into the large cavity of the mouth. Interior mucous coat of the widely dilated oesophagus organized for secreting the blood. Mouth edentate, furnished with exterior labial barbels.

Sub-Order II.—SUCKERS.

Genus *Heptatremus*, Dum. (*Beldiostoma*, Mill. Act. Berol, 1838.) A single species is known, the *Petromyzon cirrhatus* of Forster, who discovered it in Queen Charlotte's Sound, on Cook's second voyage. It has since received the appellations of *Heptatremus Dombeyi* and *Beldiostoma Forsteri*. It is a lively, active fish, inhabits rocky bottoms, lies in wait for fishes on which to prey, and was frequently taken by our voyagers adhering to pieces of fish which had been let down into the sea as bait. It has the power of emitting an immense quantity of mucus from all parts of its skin. The New Zealanders roast and eat it.

Myxine, Linn. (*Gasterosteus*, Bloch.) The species best known, *Myxine glutinosa*, Linn., or Glutinous Hag, was classed by Linnaeus with the *Vertebrata*. The mouth is a membranous ring, with a single tooth on its superior part; while the strong teeth of the tongue are arranged in two rows on each side, so as to give to these animals the appearance of having lateral jaws, like insects or *Nereides*; but their tongue performs the office of a piston in exhausting the mouth so as to enable them to adhere to other bodies, like the Lamprey. The lips are furnished with eight cirri, and above is a spout-hole communicating with the mouth; the body is nearly cylindrical, and terminates in a fin which surrounds the tail. The intestine is simple, wide, and straight, as viewed externally, but it is plaited within; the liver has two lobes; the eggs grow to a considerable size. When taken and confined in a large glass jar, a single fish will pour so much mucus from its lateral pores as to give the water the appearance of jelly.

**Ammocetes.** Body cylindrical, with numerous annular lines around it, that give it much the appearance of a worm. It lives in the mud of rivers. Mouth incapable of adhering by suction to other bodies; fins very shallow; tail sharp at the tip. The only species is *P. branchialis*, Shaw (the Pride of Pennant), which grows to six or eight inches long, and is as thick as a goose-quill. It inhabits the rivers of Oxfordshire, and occurs in various parts of the European continent.

**Petromyzon**, Dum., or Lamprey. The tongue, acting like a piston in the circular mouth, is capable of vigorous motion, and is an essential part of the mechanism by which the fish is enabled to attach itself firmly to stones, or to fasten itself to the larger fishes, which it is thus enabled to suck and devour at its leisure. The dorsal fin is farther forward than the anus, and a second unites with the tail. The European species are,—*P. marinus*, the Greater Lamprey, which grows to the length of more than three feet. It is considered as a delicate food, and is caught as it ascends rivers in the end of winter and spring. Colour yellowish, marbled with brown. First dorsal fin very distinct from the second. This fish is common in the Severn, and in the mouths of many European rivers. Its supposed hermaphroditism is mentioned by Sir Everard Home.—*P. fluviatilis*, the Lampern, or Nine-eyed Eel. Length from twelve to eighteen inches; olive back, silvery below; first dorsal fin distinct from the second. Two thick teeth, separate, in the top of the maxillary ring. Ascends rivers from the sea; swarms in the Thames, Severn, and Dee. Vast quantities taken in England are sold to the Dutch for the Turbot fishery. It abounds in the rivers on the southern side of the Baltic. Both these animals are very tenacious of life, and will live many days out of water.—*P. planeri*. About ten inches long; greatly resembles the preceding; but the two dorsal fins are united. It is also an European river fish. Figs. 61, 62 show the dentition of *Petromyzon mordax*, an Australian species; the lips and their teeth being shaved off in the latter to show the pharyngeal teeth.

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**Fig. 63.**

Fig. 49 represents the lateral gill-openings of the same species, and fig. 63 the entire fish.

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**Sub-Order II.—MARSIPOBANCHIL**

*Cyclostomi*, Dum., Cuv. Gills fixed, bursiform, inoperculate, receiving the respiratory streams by apertures usually numerous and lateral, distinct from the mouth; a heart.

There are several fishes whose branchial fins are folds of skin surrounding the tail, and the rays scarcely to be perceived in any part, being soft and rudimental. They are the first in the ascending series of fishes in which the anterior end of the myelon has that ganglionic development which constitutes the brain in fishes, and which have a cartilaginous cranium for its protection. In *Ammocetes* the persistent cranial cartilage resembles the first appearance of the cartilages in the embryo of the higher fishes. In the Myxineids the neural and hemal canals of the spinal column are formed of layers of the sheath of the gelatinous dorsal chord; the neural canal extending along the whole upper part of the chord, and the hemal canal being confined to the tail. In the Petromyzons cartilaginous plates are developed in the fibrous sheath, which is the first indication of neural arches. A cartilaginous barrel-shaped basket, homologous with the branchial skeleton of osseous fishes, is provided for the support of the gills and the canals leading to them. This cartilaginous frame-work is termed by Cuvier "cotes branchiales"; and he observes, that though it is much developed in the Cyclostomes, it is scarcely perceptible in the Rays and Sharks. There are no other ribs in this order. The Marsipobanchi, however, resemble the Plagiostomes in having an undivided cephalic cartilage, a mouth-floor in the skull, and a single valvular aperture. In all other respects they differ from them, and especially in the complete absence of gill-arches, want of jaws, in the total absence of a muscular tunic to the bullar articulans, and in the arterial valves beyond the branchial opening of the ventricle being only two; they differ further in the genital organs of the one sex having no oviduct, and in the other no seminal duct.

The gills of Lampreys and Myxines are little bags, each of which has its proper artery; and its proper orifice in the pharynx through which the water flows in to pass out on the dermal side by another hole. These purse-shaped bags are called fixed lungs, in contradistinction to the gills of osseous fishes, whose external surface is free and pectinated; but Prof. Owen says, that if the outer side of each of these were adherent to the adjacent side of another, and then each bag slit open and detached from the outer integument, a gill would be formed receiving its blood from two arterial branches, and resembling, were it pectinated, the gill of an osseous fish. The genera have been characterized by the number of the exterior gill-openings.

The teeth in the Marsipobanchi are composed of indurated albuminous matter, and when macerated, flake off in successive hollow cones. Agassiz, from investigations into the embryology of fishes, thinks that the Marsipobanchi are not a proper order of fishes, but merely embryonic forms of the more developed Sharks and Rays from which they ought not to be disassociated in our systems.

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**Family I.—AMMOCETIDÆ.**

**Genus I. Ammocetes**, Dum. Mouth semicircular, edentate, the posterior lip being transverse, ciliated within; gill-bags seven, each with an external lateral aperture, and receiving streams of water from the oesophagus without a separate trachea. Olfactory organ single, opening in the median line of the dorsal surface of the head, whence a narrow canal, strengthened by cartilaginous rings, runs to the bottom of the skull, and terminates by a valvular opening in front of the occipital cartilage. The pituitary lining is plaited longitudinally.

Agassiz describes a new species, *A. borealis*.

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**Family II.—MYXINIDÆ.**

Internal branchial openings oesophageal and equal in number to the branchial sacs; external ones as many, lateral; or only one common to all the gills of a side, and then situated on the ventral aspect, four barbels on the snout, and two on each side of the mouth (each is circular); one tooth on the roof of the mouth, two rows on the tongue. Eyes as lowly organized as in the Lancelet. Naso-palatine tube having a valve at its opening on the roof of the mouth.

**Genus I. Myxine**, Lin. *Gnathostomus*, Bloch. Sacular gill-bags, six on each side, receiving the streams of water from the oesophagus by as many short tubes. The efferent tubes empty the water into a common lateral canal which terminates on the ventral aspect of the fish at the end of the first third of its length. Between this aperture and fellow of the other side, there is a larger opening rather to the left of the medial line, which admits the water into the oesophagus.

**Genus II. Rematrema.** Seven lateral branchial apertures. At the extremity of the snout, a depressed opening of a canal leading to the gills. Four rostral cirri; as many labial ones. Eyes white lateral points.

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**Family III.—PETROMYZONTIDÆ.**

Branchial organ of each side divided by transverse partitions into seven fixed chambers, which receive the water from a median canal, distinct from the oesophagus, by as many round holes, and permit it to flow out by an equal number of lateral cutaneous oriaces; the median canal lies beneath the oesophagus, opens anteriorly into the fauces by a doubly valvular orifice, communicates with the gill-chambers to the right and left, and is closed at the posterior end. Nostril single; tubular on the top of the head, leading to a globular nasal sac from a tube that descends to the base of the skull and the membrane of the palate, which closes it, leaving no perforation there. Cuvier compares this tube to a trachea. Mouth variously armed with teeth.

**Genus I. Petromyzon**, anctorm.

Dr Gray has recently proposed a new arrangement of the Lampreys. (a.) SUB-FAMILY.—PETROMYZONINA.

(With distinct teeth and eyes.)

GENUS I. PETROMYZON. Two conical upper pharyngeal teeth close together; a single crescentic under one; numerous conical labial teeth, two fringed linguals. P. marinus, and four other species.

GENUS II. LAMPTERA. Upper and under pharyngeal teeth transversely crescentic; labial teeth in two rows on the border of the lips; more interior lateral teeth bigger, irregularly twice or thrice notched; lingual teeth pectinate. P. furiensis, planeri, and two other species.

GENUS III. GROTHIA. Upper and under pharyngeal teeth transversely crescentic, the upper one-lobed; labial teeth numerous, remote, pointed, the interior ones the biggest; lingual teeth long, conical. One species. G. ovumalis.

GENUS IV. VELARIA. Upper and under pharyngeal teeth transversely crescentic; the upper bilobate; labial teeth narrow, transverse, the interior ones the biggest; lingual teeth rather long, curved. V. chilensis.

GENUS V. CARAGOLA. Two upper, three-lobed, pharyngeal teeth, widely apart; under one crescentic, nine-lobed; labial teeth four-banded; lingual teeth flat. C. lepidota.

GENUS VI. MORDACIA. Two upper pharyngeal teeth; the lateral ones tribolate; nine under conical ones in a curved row; labial teeth conical, in a single series on the margin of the lip; lingual teeth long, conical, curved. P. mordax.

(b.) SUB-FAMILY.—AMMOCETINA.

(Without teeth and with obscure eyes.)

GENUS VII. AMMOCETES. Five species.

SUB-ORDER III.—RIBBON APODALS.

These delicate, semi-transparent, and scaleless fishes are inhabitants of all the oceans, and the species are probably numerous, though it is only in localities where much attention is paid to fish that they are likely to be noticed. They are many, and of considerable variety of form in the Mediterranean, and one species is occasionally taken by keen naturalists on the English coasts. Several have been described that inhabit the Indian seas; and on Sir James Clark Ross's antarctic voyage one specimen was obtained in a high southern latitude. The absence of ossification in the skeleton, the gelatinous condition of the sheath of the spinal marrow, which, in the form of a "chorda dorsalis," reaches into the base of the skull; and the persistence of the primordial cartilaginous cranium are reasons for placing these fishes with the Dermopteri.

SUB-ORDER III.—APODES LEMNISCATI.

Ribbon-shaped, extremely compressed fishes. Gill free, sub-operculate; no sir-bladder. Skeleton cartilaginous; no scales. Blood colourless; no spleen.

FAMILY I.—LEPTOCEPHALIDÆ, Boem.

Holosteiichthyde, Köll. Small, greatly compressed, blade-shaped, apodal, diaphanous fishes, totally destitute of scales, with a lateral line formed by the intersection of the muscular layers; some have smooth want teeth, and the pectoral fins are also present in some species; the maxillae and others. The mouth placed on the ventral edge of the fish, before or behind the middle, and the simple straight gut runs near the ventral edge of the fish. Their skeleton is very incomplete and cartilaginous, and the myelose is obscurely visible through it. In most, the anal and dorsal, uniting at the end of the tail, form a pointed or blunt, but very seldom a forked caudal, in which the rays are generally discoverable.

GENUS I. ESANGULUS, Kaup. Leptocephalus with small pectorals and a forked caudal. One species, Italy.

GENUS II. HYPORES, Köll. Jaws straight, much elongated, with merely traces of dentition. Hind nostrils before or over the eyes. No external pores along the jaws and round the eye. Body elevated and gibbous at the expense of pointed. Pectorals minute; rudimentary anus before the middle; caudal not distinct from the other visceral fins. One species, Messina.

GENUS III. OXYSTOMUS, Rafin. (Tiberius, Köll.) Distinguished from Leptocephalus by the rayless, cutaneous dorsal fin commencing at the occiput, and by the upper and under transverse muscular bands not making an angular intersection or break anteriorly at their intersection; no anal fin; anus far back, near where the tail is attenuated into a longish filament. Head small; Classica mandible a trifle longer; pointed teeth on both jaws; gill-openings thin—Der- furnished with distinct opercula, and squeezed together on the nape of the throat. Three species.

GENUS IV. LEPTOCEPHALUS, Lin. (Heliodorakis, Rafin.) Distinguished from Oxystomus by none of the species having the tail so prolonged into a hair-like point, and by the muscular bands making a distinct angular intersection anteriorly. Some species have, others want teeth; there are species in which the teeth can be seen only through a microscope, and others whose pointed teeth are distinctly visible to the naked eye. Most have small pectorals, but some show not even traces of these fins. At the end of the gut there is an anal opening as fine as a hair, which gives exit to the fluid excrement. Eighteen species.

GENUS V. CHEILOBRANCHUS, Rich. Form compressed; body linear-lanceolate. Head very small; snout obtuse; jaws equal. Mouth small; teeth uniseriate, acute, becoming blunt with age, closely ranged so as to form an incisorial series; lips loose. anus before the middle; dorsal and anal mere cutaneous folds without rays or internumeral bones; a single internumeral at the point of the tail, which supports seven or nine jointed rays; caudal united with the transverse dorsal and anal; muscular layers forming chevrons, which have the edge of each angle on the lateral line, and directed forwards, as in Leptocephalus; abdominal and apodial. Gill-opening under the throat, a small transverse slit, common to the two sides, without a division in the middle; the edge of the membranous face, a cutaneous fold, ending on each side in a minute lobe, forms the posterior edge of the opening, and seems to be capable of acting like a valve, with the aid of an interior membranous fold; branchiostegals three; a minute genital papilla; a single pancreatic cecum was observed; the intestine appeared to be straight, with a stomacal dilatation. The skin is smooth, but minutely pitted, as if from microscopic sunken scales. Vertebrae 73, ossified. Two species—one obtained at Penguin Island, in Lat. 72° S.

ORDER II.—MALACOPTEROUS FISHES.

SUB-ORDER I.—SERPENTIFORM APODALS.

In the Lancelets, the only representatives as yet known of the order of Dermopteri, we have seen that the skeleton is membranous, that the spinal nervous chord is continued to the anterior end of the fish without expansion, and that in conformity with this simplicity of the nervous centre, the head cannot be distinguished from the body, and may be said to be wanting,—the only part of the face that is developed being the mouth and oral filaments. In the Suckers the skeleton rises from the soft membranous condition of that of the Ammocete, to the production of a tendinous spinal chord filled with gelatine, and partially encompassed by cartilage; teeth exist on the palate and lips, though as yet seated only in the soft parts, and formed of indurated mucoid matter; while the jaws are wanting. The group we have now to speak of consists of fishes with a well ossified skeleton, and a head that is at once recognised as such, but with the bones of the face less fully developed than in osseous fishes more highly organized. A single bone represents the nasal, ethmoid, and vomer, or it may be said that these three bones have coalesced into one, which is firm and strong. The pre-maxillaries and the maxillary are wanting, the palatines coming in contact with the lips to form the lateral portions of the upper jaw, which are opposed to the mandible,—the teeth which arm these bones standing in reverse order with regard to one another; for instance, when they are biserial, and the inner row is the tallest on the palatines, the outer row of the mandibulars is the tallest, and is opposed to the lower rank of the palatines. In the mammals a similar reversal of the sides of the molar teeth may be noticed in comparing the upper and lower jaws.

This sub-order does not embrace all the fish that want ventral fins, there being many examples of such in other groups, but it may be viewed as presenting an analogy to the Cetacei among mammals. Neither does the vermiform type belong exclusively to these Apodals; we shall find it manifested repeatedly in other parts of the series of fishes.

The table in small type gives the technical characters of the various divisions and sub-divisions of the order, and our limits will not permit us to do more than to notice a few of the species that inhabit the British waters, or that are otherwise interesting from some particulars in their history or economy.

In this order the forms of the teeth vary greatly. In a few species they are mere grinding machines, in the majority, long, slender, and sharp for the retention of their prey; in others, they are variously lobed, fine-edged, cutting instruments. On these different kinds of dentition, the genera and minor groups are, in many instances, founded. The arrangement of the entire sub-order is that of Dr J. Kaup of Darmstadt, from whose catalogue, written for the British Museum, we have borrowed it.

The *Murana Helena*, or *Roman Murana*, abounds in the Mediterranean, and was introduced by the luxurious Romans of antiquity, in crystal vases, to the table before being cooked, that the guests might admire its variegated skin. This fish is very voracious, and feeds on all sorts of animal matter. The Romans fed them in ponds, and Pliny has recorded the atrocities of Vedius Pollio, who used to punish his offending slaves by throwing them alive to his *Murane*. We have seen this fish repeatedly taken at Gibraltar, between three and four feet in length. The skin is beautifully marbled with yellow sub-angular markings on a rich brown ground. When captured in nets it lives long out of the water, and is capable of biting very severely, from the sharpness of its numerous teeth.

A Murry is noticed in the narrative of Cook's Third Voyage to the Pacific in these words:—"Amongst these were some large eels, beautifully spotted, which, when followed, would raise themselves out of the water, and endeavour, with open mouth, to bite their pursuers."

The *Anguillidae* are a family whose members exhibit little variety of form, and it contains only a single genus. From the common Eel, however, most of our ideas respecting the Apodals have originated. *Anguilla vulgaris*. We have observed these fish in considerable numbers leaving fresh-water lakes in the night time, and frequenting meadows, seemingly for the purpose of preying on slugs and snails. They easily move on the land, with a motion resembling that of snakes. The Eel grows to the size of two or three feet, and is sometimes said to reach five or six feet in length. It abounds in many European rivers. Eels are caught in immense numbers in the rivers emptying themselves into the Baltic; and they form a considerable article of trade. Two thousand are stated to have been caught at one sweep in Jutland; and in the Garonne 60,000 were taken in one day by a single net.

"That Eels migrate towards brackish water," observes Mr Jesse, "in order to deposit their roe, I have but little doubt, for the following reasons. From the month of November until the end of January, provided the frost is not very serious, Eels migrate towards the sea. The Thames fishermen are so aware of this fact, that they invariably set their pots or baskets with their mouths up stream during those months, while later in the spring and summer they are set down stream. The best time, however, for taking Eels, is during their passage towards the sea. The Eel-traps, also, which are set in three different streams near Hampton Court (the contents of which, at different times, I have had opportunities of examining), have invariably been supplied with Eels sufficiently large to be breeders, during the months I have mentioned. This migratory disposition is not shown by small Eels; and it may therefore be assumed that they remain nearly stationary till they are old enough to have spawn. I have also ascertained that Eels are taken in greater or lesser numbers during the months of November or December, all the way down the river to the brackish water. From thence the young Eels migrate, as soon as they are sufficiently large and strong to encounter the several currents of the river, and make their way to the different contributory streams. I have also been able to trace the procession of young Eels, or, as it is called here, the *Eel-fair*, from the neighbourhood of Blackfriar's Bridge, as far up the river as Chertsey, although they probably make their way as far, or farther than Oxford. So strong, indeed, is their migratory disposition, that it is well known few things will prevent their progress, as, even at the locks at Teddington and Hampton, the young Eels have been seen to ascend the large posts of the flood-gates, in order to make their way, when the gates have been shut longer than usual. Those which die stick to the posts; others, which get a little higher, meet with the same fate, until at last a sufficient layer of them is formed to enable the rest to overcome the difficulty of the passage. A curious instance of the means which young Eels will have recourse to, in order to perform their migrations, is annually proved in the neighbourhood of Bristol. Near that city there is a large pond, immediately adjoining which is a stream. On the bank between these two waters a large tree grows, the branches of which hang into the pond. By means of these branches, the young Eels ascend into the tree, and from thence let themselves drop into the stream below, thus migrating to far distant waters, where they increase in size, and become useful and beneficial to man. A friend of mine, who was a casual witness of this circumstance, informed me that the tree appeared to be quite alive with these little animals. The rapid and unsteady motion of the boughs did not appear to impede their progress."

"All authors agree," adds Mr Yarrell, "that Eels are extremely averse to cold. There are no Eels in the Arctic regions, none in the rivers of Siberia, the Wolga, the Danube, or any of its tributary streams. It is said there are no Eels in the Caspian or Black Seas, but they abound in the Mediterranean; and M. Risso has described eight species in his work on the *Natural History of the Environs of Nice*. There is no doubt, also, that fishes in general, and Eels more particularly, are able to appreciate even minute alterations of temperature in the water they inhabit. The brackish water they seek to remain in during the colder months of the year, is of a higher temperature than that of the pure fresh water of the river, or that of the sea." It is a well-known law in chemistry, that when two fluids of different densities come in contact, the temperature of the mixture is elevated for a time, in proportion to the difference in density of the two fluids, from the mutual penetration and condensation. Such a mixture is constantly taking place in rivers that run into the sea, and the temperature of the mixed water is accordingly elevated." As Eels are well known to breed in ponds, it may be inferred that their descent to the brackish water, though customary, is not indispensable. They sometimes attain a great size. The species (or variety) called the Sharp-nosed Silver Eel has been taken near Cambridge of the weight of twenty-seven pounds.

ORDER II.—MALACOPTERI.

Ptyctostomi, Müll. Endo-skeleton ossified; exo-skeleton, in most as Cycloïd, in a few as Ganoid scales. Fins supported by rays, all save the first, sometimes in the dorsal or pectoral, soft or jointed abdominal or apodal. Gill free, operculate; a swim-bladder and air-duct.

SUB-ORDER I.—APODES ANGUIFORMES.

Malacopterygii apodes (partim), Cuv. Elongated fish more or less approaching to vermicular, covered with a thick slimy skin; the majority scaleless, but in some genera small scales are imbedded in the skin. No developed ribs in the skeleton. Stomach caecal. Pancreatic caecal appendage to the intestine wanting. The greater number have a swimming-bladder, which is often very curiously formed, but never double. Fin rays simple, not jointed.

SECTION A.—Phaneromysteres.

Labial olfactory organ opening by the posterior nostril on some part of the head above the mouth, so as to be exposed.

FAMILY I.—SYNBRANCHIDÆ, Kaup.

Uni-opercularis, act. Both gill-openings enveloped by a border of the common integument, so as to present externally only a single medial orifice. Pectorals and other fins wanting, or almost obsolete. Species few, confined to the seas of Asia and South America.

GENUS I. AMPHIPHONUS, Müll. (Unibranchioperca, Hamilton; Bouch.; Synbranchus, Cuv.; Ophichthys et Paracanthobranchus, McClell.)

A membranous partition separates the branchial efferent tubes, and is continued to the verge of the common orifice. Four gills, the third one having short fingers; the fourth, a membrane with many fine filaments reaching its extremity. Vomerine teeth strong, in two rows, eight in each, standing well apart; palatine teeth small and thin, a little larger on the point of the tooth; palatine teeth pluriseriatus at the symphyses, uniseriatus towards the corner of the mouth. On the occiput there is a sac which can be filled with air, and is connected with the gills. Fine scales form a multitude of elevated longitudinal lines on the body. The only trace of a fin is a slight one on the thin tapering end of the tail. One species, A. cuchia.

GENUS II. OPHISTERNON. (Unibranchioperca, Lacép.; Ophisteron, McClell.; Synbranchus, Cant. and Bleek.) Four fringed branchial arches which discharge the water that has passed over them by two tubes, which diverge at the thin partition inclosed by the skin of the throat so as to form one transverse oval opening. No air-bag on the occiput, and no swim-bladder. Branchial integulae bony. Posterior apertures of the nostrils between the eyes; anterior nostrils minute, one on each side of the snout. Teeth fine, blunt on the upper jaw, almost setaceous, crowded into a triangle on each side of the symphyses; vomerine teeth larger, in a single series; mandibular ones somewhat bigger still, and truncated. One species, O. hengaloensis.

GENUS III. SYNBRANCHUS, Bloch. Have all the characters of Ophisteron, but the four fringed gills are not separated under the branchial partition, and the solitary gill-opening does not make the angular indentation that it does in Monopterygus, Ophisteron, and Amphipnous. hinder nostrils opening above the eyes, and capable of being shut by a cutaneous flap. Two species, one Indian, the other South American.

GENUS IV. MONOPTERYGUS, Lacép. Three gills only. No occipital air-bags. No protruding nasal teeth; the palatine teeth meet in an angle with the vomerine ones anteriorly, and are there pluriseriatus, but diminish to two and one row towards the corner of the mouth; vomerine teeth triseriatus anteriorly, uniseriatus posteriorly; ranged in two bands, which meet in an acute angle anteriorly, and diverge posteriorly. Like Amphipnous and Ophisteron, the external gill-opening is angular, and below the outer integument there is a membranous partition between the gills. One species, M. lacopteri.

FAMILY II.—MURÈNIDÆ, Kaup.

In most of the genera no pectorals. Gill-openings lateral. Skin smooth and slippery, without scales. Mostly or wholly marine fishes.

(a.) SUB-FAMILY.—MURÈNINÆ.

Uniseriatus teeth on nearly all the dentiferous bones of the mouth.

GENUS I. MURÈNA, Kaup. Uniseriatus nasal teeth, three on the mesial line. Twenty-four species. Figure 64 represents Murèna perspicua.

GENUS II. SIDERA, Kaup. Only one short conical tooth on the mesial line; biseriatus, low, granular teeth on the vomer, the rows coalescing in a point posteriorly; opening of the jaws not wide. Skin spotted. Two species. Figure 65 represents Sidera pantherina.

(b.) SUB-FAMILY.—THYRSOIDEINÆ.

Within the outer palatine teeth, a second row that varies much in the number of teeth which compose it.

GENUS III. ENCHELYNASSA, Kaup. Fore nostril short, infundibuliform, and capable of being closed by a cutaneous tag of its hinder border; hinder nostril longish, oval, surrounded by an elevated cutaneous border, and nearly as large as the eye. Rictus of the jaws gaping in the middle, owing to the length of the teeth; nasal teeth, five long ones anteriorly, followed by three or four smaller ones; in the second row three long moveable teeth standing near the margin of the eye; nineteen greater and smaller palatine teeth, with six more anterior ones in an anterior row on the mesial line of the nasal, three long moveable teeth on the vomer, two short conical ones; mandibular teeth, twenty-two small ones in the exterior row, and five long ones in an interior row. One species. The teeth are shown by figure 58.

GENUS IV. ECHYMICERA, Kaup. Fore-nostril tube projecting outwards beyond the lip; lips expanding on the upper and under jaws; hinder nostril over the eye, and encompassed by an infundibuliform border. Nasal teeth eleven, with five small intercalary ones in the posterior part of the row; palatines thirty in the outer row; five larger ones forming an inner row; from seven to ten on the vomer; the extreme ones minute; mandibulars twenty-seven of a side, with five larger ones near the symphyses in a second row. Body slim. Jaws deeply cleft. Dorsal fin commencing at the occiput. One species.

GENUS V. ENCHELICORE, Kaup. Jaws incapable of shutting close from the length of the teeth; hinder nostril strikingly large, longer than broad, and situated before the eye; fore nostril-tube so unusually short that it does not pass over the edge of the lip, and it has no lid; eye in the middle of the length of the snout; the thin outstretched upper jaw curves upwards. Twenty-four slender teeth, some of them elongated, forming the outer row on the nasal bone; eight moveable latter ones in a second row; three on the mesial line; eighteen on the palatines; three moveable bigger ones making an inner row; about fifteen small, pointed vomerines, and thirty-seven fine mandibular ones, with two bigger moveable ones at the symphyses. One species.

GENUS VI. THYSOIDEA, Kaup. Murènas in the construction of the fore and hinder nostrils, and presenting no prominent character whereby they may be distinguished from the Murènas proper, except that they possess a more or less complete second or inner row of pointed palatine teeth.

The numerous species (33) may be grouped according to the numbers of rows of their vomerine and palatine, and by the patterns which the colours of their bodies assume;—some are reticulated, others spotted, either again of one uniform colour in the upper, or both above and below.

GENUS VII. LIMAMURÈNA, Kaup. Abbreviated Thyroideinae, whose hinder nostril-tubes project still more than those of Murèna lateno. Ten or twelve nasal teeth, with some scarcely perceptible ones at their bases; three on the mesial line; palatine teeth biseriatus, but the inner row of six generally defective, sometimes altogether wanting; four to six vomerine teeth; mandibulars uniseriatus, nine of them taller than the fourteen others.

Head elongated; snout pointed; front nostril-tubes projecting over the edge of the lip; hinder ones a little exceeding the diameter of the eye in length. Dorsal fin commencing at the occiput. One species.

GENUS VIII. POLYURANODON, Kaup. Thyroideinae, with three rows of acute teeth on the palatine bones; fourteen uniseriatus nasal teeth; five or six uniseriatus vomerine teeth, mandibulars quadriseriatus anteriorly, biseriatus towards the corner of the mouth. One species. Genus IX. Channomuraena, Rich. (Ichthyophis seu Nata- stoma, Rich., idem.) Nostrils like Maranota; face short and de- pressed, but the gape of the mouth extremely wide and long. Body cylindrical, without any vestige of the fold of the skin which contains the dorsal rays in Maranota. Tail compressed and thinner at the tip, where a few caudal rays are faintly perceptible. Teeth slenderly subulate, in broad, dense, coarsely villiform plates. One species. It is represented by figure 6.

Genus X. Murnonellena, Lacép. (Ichthyophis, Less., Rich. partim.) Finless, like Gymnomuraena, but differing wholly in the teeth, which are slenderly subulate, rather tall, and thinly set. Vo- merines irregularly biserial; nasals, palatines and mandibulars tri- serial.

Genus XI. Pecilophis, Kaup. Maranota, with blunt or more conical teeth; vomerines round, pavement-like. Hinders nostrils fringed; front ones shortly tubular, not projecting over the lip. Dorsal and anal fins not distinctly perceptible, and the species are therefore to be distinguished from Gymnomuraena by the numerous rows of vomerine teeth. Six species, most of which are much spotted.

Genus XII. Gymnomuraena, Lacép. Destitute of fins; blunt, pavement-like teeth on the branchial and mental lines of the nasal bones, crowded into a space shaped like the head of a nail. Palati- ne bones rudimentary; upper jaw with small teeth in two or three rows. Body elongated, covered by white bands. Two species.

Genus XIII. Antennichthys, Kaup. Resembling Morayna, but destitute of fins except at the point of the tail, where there is a trace of rays. Eyes covered by the skin. Lower jaw thick and pro- jecting beyond the snout. Nostrils short and tubular, the posterior ones capable of being shut. Tail nearly equally thick throughout. Eleven teeth in the upper jaw, the seven nasals being the longest; five vomerines in one row; ten or twelve mandibulars. One species.

Genus XIV. Uropterygius, Hipp. Both jaws furnished with two rows of fine teeth; the teeth in the outer row being short, with reflexed points; those of the inner ones elongated and twice as high; vomerine teeth uniseriatus. The only fin is the cau- dals, set on the dilated tip of the tail. One species.

Genus XV. Anteichthys, Dum. (Cephaloscyllium, Lacép.; Sphynx- branchus, Blech., Cav.) No fins. Snout lengthened beyond the mandible; gill-openings near to one another, as in Sphynx- branchus; anterior and posterior nostrils tubular. Body much elon- gated; tail slender. Teeth acicular and curved, and uniseriatus on all the dentiferous bones. One species.

Genus XVI. Phymothorax, Rich. Founded on a pencil draw- ing of Dr. Hooker's; has an acute snout, projecting a little be- yond the mandible. Acute uniseriatus uniseriatus teeth, not recurved. Anal aperture near the snout, a long evagination with lateral rays shown posteriorly united to a rudimentary caudal; a short dorsal fold also united to the caudal. Gill-openings lateral; a small hole in the axilla of what seems to be a small pectoral. No specimen of this form has reached England. It appears to belong to this place.

Genus XVII. Morinqua, Gray. Greatly elongated Moranota, with the mandible longer than the snout. Teeth distinct, acute, and recurved; vomerines uniseriatus. The dorsal and anal fins commence posterior to the anus, and disappear in the middle of their length, reappearing and becoming higher than before at the end of the tail. Three species.

Family III.—Anguillidae.

Teeth card-like or villiform. Gill-openings lateral. Pectoral fins completeness; anal and dorsal fins encompassing the tip of the tail, the former beginning generally at a considerable distance from the head; longitudinal oval cycloid scales lying embedded in transverse and oblique groups in the skin, so as to resemble lattice-work. No species have as yet been detected that want the pectoral fins, like the abranchial genera among the Muronidae and Synodidae. The Anguillidae are wholly, or mostly anadromous fishes, some of them remaining always in fresh water.

Genus I. Anguilla. Forty-five species.

Family IV.—Congeride, Kaup.

A dorsal fin reaching up to the occiput; a naked, scaleless skin; and, for the most part, a very long tail running to a point. Pec- torals in some present, in others wanting; a cartilage in the lips.

Genus I. Murenexos, McClell. Snout elongated like that of a Gavial, whereas the dilated spoon-shaped nasal bone over- passes the mandible; the thin lips do not cover the front teeth. Fore nostrils opening by short tubes near the narrowing of the nasal bone; hinder ones often pretty remote from them, placed beneath the eyes. The large eyes placed nearly over the middle of the jaws. Dorsal fin extending forwards to the base of the pec- torals; vomer elevated with a furrow in which the bigger teeth stand, and are accompanied by a row of small blunt ones. Sun- gle rows of teeth on the palatine and mandibular bones; the clas- siest longest teeth are on the nasal bone and fore part of the mandible.

Genus II. Conger, Cav. Anterior nostrils opening by short tubes close to the end of the snout; posterior ones before the large eyes. Palatine and vomerine teeth slender, but having chisel- shaped crowns, and arranged in so close a series as to produce an incisorial edge. Nine species.

Genus III. Congermurrena, Kaup. Posterior nostril a short longitudinal slit before and above the large eye, which is over the corner of the mouth. Teeth flatly rounded in a multitude of rows. Species thirty-three.

Genus IV. Uroconger, Kaup. Anterior nostril not tubular; posterior ones close before the eye like a small slit. A row of slit- like pores on the border of the upper lip. Tail much elongated, slender towards the end, and tapering to an acute point. Teeth (like those of Myrus) very fine, and disposed in two or three rows; nasal and palatine teeth in two rows; front upper jaw teeth boring through the lips; pectoral small and elongated. Gill-openings very large, as compared with those of other genera in this family. One species.

Section B.—Cryptomyctere.

The olfactory canal, running from the front nostril backwards through the soft parts to the side of the mouth, opens by the pos- terior nostril in the white integument within the border of the lip; in this respect resembling Lepidogaster.

Family V.—Ophisuride, Kaup.

(a.) Sub-Family.—Ophisurinae.

Tail ending in a conical point, that separates the ends of the ver- tical fins; no caudal fin.

Genus I. Leucanurus, Blech. No vomerine teeth; uniseriatus palatine teeth in a crescent; mandibulars also uniseriatus; upper jaw elongated like that of a shark; mandible extraordinarily short and round. Fore nostrils under the projecting snout; hinder ones in the lip beneath the eye, which is nearer the corner of the mouth than to the point of the snout. Pectoral fins scarcely per- ceptible. Point of the tail spinous. One species.

Genus II. Centrophorus, Kaup. Vomerine teeth uniseriatus or sometimes sub-biseriatus; nasal teeth beyond the point of the man- dible. Pectoral fins pretty well developed. Six species.

Genus III. Porichthys, Kaup. The nostrils, not im- planted out of reach of the mandible; three on the medial line, the foremost one smaller than side by side. Eleven palatine teeth in a crescent, whose point touches the last of the nasal nasals; eleven vomerines; nineteen mandibulars; teeth generally pointed, short, and recurved. No cuticular processes on the upper lip. Head roundish. Pectoral fins very short; dorsal commencing opposite their bases. One species.

Genus IV. Microdonophis, Kaup. Very small pointed teeth, biseriatus on the nasal and on the symphysial extremity of the man- dible. Fins much developed. One species.

Genus V. Coccilophis, Kaup. Biseriatus teeth near the symphysia of the mandible, and not elsewhere. Pectoral fins developed and rather than the rays of the mouth. Fore nostrils shortly tubular, with a short tube on their under border. Dorsal fin commencing over the points of the pectorals. One species.

Genus VI. Ophirhena, Kaup. Head small; snout slender and elongated, its point passing beyond the mandible; gape of the mouth very wide; eyes near the corner of the mouth; fore nostril in the middle between the eye and end of the snout, indistinct and without a tube; and the hinder one rather on the outside of the thin lip. The pectoral fin is about half as long as the mouth.

Nasal teeth, five on the border of the bone, and nine longer ones on the medial line; thirteen short and pointed ones on the vomer; palatine teeth uniseriatus, anteriorly, becoming biseriatus under the eyes. One species.

Genus VII. Herpetichthys, Kaup. Jaws nearly of equal length; snout bluish; gape wide; eyes approximating to the snout; head depressed, so that the eyes are rather more on the dorsal than lateral aspect; fore nostril-tubes at the end of the snout, and the hinder ones at the commencement of the outer row of palatine teeth; between the two there is a small cutaneous flap on the border of the lip. Pectoral fins pretty short. Six nasal teeth; from nine to thirteen vomerine ones. Three species.

Genus VIII. Brachysomophis, Kaup. Eyes placed at the end of the first fifth part of the length of the body; snout as in its own diameters from the tip of the snout; fore nostril-tube extraordi- narily short; the hinder one a short tube on the inner side of the lip under the eye; gill-openings very large, and approximated to one another. Pectoral fins comparatively small. Border of the lips warty. One species, B. horridus, whose jaws are represented by figure 59. Genus IX. Elapsopsis, Kaup. Gape of the mouth short; snout elongated, obtuse, stretching beyond the mandible; the short nasal tube wider at its external orifice than at its commencement; eye approximating to the corner of the mouth. Pectoral very small but distinctly visible. Body about equal in length to the tail. Nasal teeth reflex, four in each row, with an odd one in front; vomerine teeth irregularly uniseriatal; palatine teeth uniseriatal anteriorly, becoming biserial and sub-triseriatal. One species.

Genus X. Mysteripinnis, Kaup. Snout spoon-shaped, its external border being united; fore nasal-tube rudimentary, and in the middle of the rostral expansion; eyes over the middle of the jaws, and though the long head is depressed, they are more lateral than dorsal in their aspect; gill-openings large and near one another. Two species.

Genus XI. Murexopsis, Lesueur. Head oval; snout not much elongated; hinder nostril rather on the outside of the thin lip. Pectoral as long, or somewhat longer than the long, straight rictus of the jaws. Teeth all of equal length. Three species.

Genus XII. Echionops, Kaup. Face short; eyes high-placed; fore nostril-tube short; jaws deeply cleft. Pectoral fins pretty short, about half the length of the oral rictus. Nasal teeth seven; three on the medial line being the tallest; two rows of vomerines uniting at their posterior termination, biserial palatines, interior row composed of vomerine teeth; two rows on the mandible, the anterior row being the tallest. One species.

Genus XIII. Scytalophis, Kaup. Teeth all nearly of a size, divergent; anterior nostril-tube distinctly visible. Pectoral pretty well developed. All the teeth biserial except the nasals. Two species.

Genus XIV. Leptorhinopshis, Kaup. Snout pointed; tubes of the anterior nostrils dependant; posterior nostrils situated before the eyes on the border of the lips; eyes over the middle of the oral rictus. Pectorals developed; anal and dorsal fin becoming higher near their terminations. Two species.

Genus XV. Pseudonophis, Kaup. Teeth all shortly conical, more or less blunt; anterior nostril-tube projecting; eye approximating to the corner of the mouth. Pectoral more or less fully developed. Eighteen species, some of them all of one colour, others spotted or banded. Eighteen species.

Sub-Order II.—APODALS WITH ARTICULATED FIN RAYS.

The Gymnotidae are apodals, but cannot be associated with the Eels in the sub-order of Serpentiform Apodals, owing to the considerable differences of their organization. Their jaws are complete, they are furnished with ribs, and their fin rays are jointed or branched, in which respect they differ from the preceding sub-order, the chief point of agreement being the want of ventral fins. The Gymnotidae want also the dorsal; but one of the genera has a curious long ray, which commonly lies in a furrow along the top of the rounded back, glued down by mucus. It is named by German ichthyologists “peitsche,” or “the whip,” and is considered by Dr Kaup to be a representative of the adipose fin on the tail of the Salmonoides. One of the most curious parts of their structure is the forward position of the vent, which in most of the Rhamphichthys is before the eye; and in these the anal begins between the gill plates, and extends along the ventral edge of the fish, while the rounded back is destitute of a fin. Examples of a similar forward position of the anus occurs in some other families, but they are very scarce. The Gymnotidae inhabit the rivers and fresh-water lagoons of the warmer parts of South America, Guiana, Surinam, Cayenne, Demerara, Guayaquil, Ecuador, New Granada, and Brazil. The best known species is Gymnotus electricus, or the Electric Eel. This animal has been well described by Dr Garden of Charlestown, by John Hunter, and by Humboldt. It is remarkable for the violence of its electric shocks, which are often so powerful as to stupify a man or a horse. The researches of Hunter detected an electric organ in the posterior part of this fish consisting of four longitudinal fasciculi, which occupy one-half the thickness of the part in which they occur, and about one-third of the whole animal. The larger pair lie above, the smaller below. Each fasciculus is composed of flat partitions or septa, with transverse divisions between them. The outer edge of the septa appear in nearly parallel lines in the direction of the longitudinal axis of the body, and consist of thin membranes, which are easily torn; they serve the same purpose as the columns in the analogous organ of the Torpedo, making the walls or abutments for the perpendicular and transverse dissepiments, which are exceedingly numerous and so closely aggregated as to seem almost in contact. The minute prismatic cells, intercepted between these two sorts of plates, contain a gelatinous matter; the septa are about one-thirtieth of an inch from each other, and one inch in length contains a series of 240 cells, giving an enormous surface to the electric organs. The whole apparatus is abundantly supplied with nerves from the myelon; and these nerves are seen coming out in pairs from between the vertebrae. In their course they give out branches to the muscles of the back, and to the skin of the animal. In the Gymnote, as in the Torpedo, the nerves supplying the electric organs are much larger than those bestowed on any part for the purposes of sensation or movement. Hunter thinks, however, that these nerves are more considerable in point of size in the Torpedo than in the Gymnote. These organs are attached loosely to the muscles of the back which lie between the larger fasciculi, and they are immediately connected with the skin by a loose cellular texture. Humboldt has given a very interesting and lively description of the mode of capturing the electric Gymnote, as practised in South America, near the town of Calabozo.

These fish abound in the stagnant pools of that vicinity. The Indians are well aware of the danger of encountering the Gymnote when its powers are unexhausted. They therefore collect twenty or thirty wild horses, force them into the pools, and when the fish have exhausted their electric batteries on the poor horses, they are laid hold of without difficulty. The horses at first exhibit much agitation and terror; they are prevented leaving the pool by an inclosing band of Indians, who goad them with bamboos whenever they attempt to escape. “The Eels,” says Humboldt, “stunned and confused by the noise of the horses, defended themselves by reiterated discharges of their electric batteries. For some time they seemed likely to gain the victory over the horses and mules; these were seen in every direction, stunned by the frequency and force of the shocks, to disappear under water. Some horses, however, rose again, and, in spite of the active vigilance of the Indians, gained the shore, exhausted with fatigue; and their limbs being benumbed by the electric explosions, they stretched themselves out upon the ground." "I remember the superb picture of a horse entering a cavern, and terrified at the sight of a lion. The expression of terror is not there stronger than what we witnessed in this unequal conflict. In less than five minutes two horses were already drowned. The Eel, more than five feet long, glides under the belly of the horse or mule; it then makes a discharge from the whole extent of its electric organs, which at once attacks the heart, the viscera, and especially the gastric plexus of nerves." "After this commencement, I was afraid that the sport might end very tragically. But the Indians assured us that the fishing would soon be finished, and that nothing is to be dreaded but the first assault of the Gymnotus. In fact, whether the galvanic electricity is accumulated in repose, or the electric organ ceases to perform its functions when fatigued by too long-continued use, the Eels, after a time, resemble discharged batteries. Their muscular motion is still equally active, but they no longer have the power of giving energetic shocks. When the combat had lasted a quarter of an hour, the mules and horses appeared less affrighted; they no longer bristled up the mane, and the eye was less expressive of suffering and of terror. They no longer were seen to fall backwards; and the Gymnotes, swimming with the body half out of the water, and now flying from the horses instead of attacking them, began themselves in their turn to approach the shore."

The electric Gymnote is by no means fierce or voracious; but its electric organs are the instruments by which it procures its prey, and defends itself against alligators and other enemies. It has been several times brought alive to Europe, and some experiments have been made on its electricity, which is conducted and insulated by the same substances as common galvanism. So common is the Gymnotus in some parts of South America, that, in the neighbourhood of Uritucu, a route at one time much frequented has been entirely abandoned, in consequence of the necessity of fording a stream, in which many mules were killed every year by these subaqueous electric shocks.

The genus Sternarchus of Schneider was so denominated from the anus being near the sternum. The Gymnarchus niloticus is named in Arabic "Del e far."

SUB-ORDER II.—APODES ARTHROPTERYGII.

Dr Kaup, for the reason stated in the text, has separated Gymnotus from the Serpentiform Apodals, and associated it with Sternarchus and its allies, forming a group placed by him next the Malacopteryi abdominales, but the want of ventrals necessitates its separation as a sub-order.

FAMILY I.—GYMNOTIDÆ.

Eel-like, the back round, and without fins; pectorals; largely developed anal fin, extending either to the point of the tail, or leaving the extremity free; with or without teeth on the pre-maxillaries, mandible, and palatines; no teeth on the vomer; scapular arch attached to the head; from the fifth vertebra onwards distinct ribs encompass the belly, and in many species are perceptible through the skin; stomach caecal; pancreatic caeca; ovaries pouch-shaped, and their outlets different from those of the Eels; vent and the genital papilla behind it on the coracoïd bone, or still farther forward towards the middle of the mandible.

There are four bladders under the second, third, and fourth vertebrae; pyriform, hand-shaped, and is double; the outer one being thin, white, and easily torn; the inner transparent, filled with a gelatinous fluid, and swimming loose in the outer one. This bladder is attached to the acoustic bones of the skull, and is connected by a fine chord with the simple posterior or ordinary swim-bladder, which chord divides, and with its fellow is attached to the stomach. The anterior double-bladder closely resembles that of the Carassius (which is followed by two or three ordinary swim-bladders), belongs to the organs of hearing, and corresponds to the membranous labyrinth of the higher mollusks.

GENUS I. Gymnoterus, Linnaeus. Skin entirely soft; pointed dentition of scales; mouth very large; eyes known; skin rather slender Coropuss in the conformation of the head, position of the nostrils, and dentition; but the nasal fin reaches the tail. Head oval, flatly depressed; mouth not opening quite as far as under the eyes, furnished with broad lips of equal length; fore nostril a small tube in a bell-shaped superficial depression above and towards the end of the lateral lip; hinder nostril distant about the diameter of the eye from the first one, behind and above it. Longitudinal and transverse rows of pores in cup-shaped depressions on the top of the head; also a row on the mandible; lateral line indicated by a row of distant pores.

About fifty pointed teeth on the upper jaw, and sixty on the lower one; a second row behind the middle of the upper ones of about six teeth; along the symphyses of the mandible two short rows, each with two toothlets. Vomer, roof of the mouth, and tongue furnished with lateral, projecting, denticulated membranous edgings. Vent before the gill-openings; behind it a small orifice and a small, slender papilla. Pectorals and anal fin enveloped in a thick skin which conceals the rays. One species.

GENUS II. Carapus, Müll. and Troesch. (Carapus, Cuv. parsim.) Broad, depressed; flattened snout; a row of pointed teeth; scales. No caudal fin. Fore nostril a short tube in a notch near the corner of the mouth; hinder one before the eye, open and distinct; eyes shining through the skin; five broad, flat branchiostegals; anal fin extending almost to the end of the tail; under lip longer than the upper one. Scales of the back and lateral line of equal size. Two species.

GENUS III. Sternopygus, Müll. and Troesch. Card-like teeth in numerous rows; small mouth. Body and head compressed; head short; small jaws; occasionally traces of card-like palatine teeth. Tail slenderly prolonged, without a caudal fin. Scales of the lateral line mostly larger than the others.

This genus has the aspect of a Flounder. Four species.

GENUS IV. Rhamphichthys, Müll. and Troesch. A small mouth; no teeth; snout more or less tubularly elongated, and provided with small pores; nostrils not tubular. Head and body compressed, and with an exception scaly. Anal fin long, but leaving the end of the tail free.

The species divide themselves into two groups:

1. Snout short; largely developed genital papilla. Anus behind the third part of the head; and anal fin commencing at the point of the pectoral. Two species.

2. Anus under or before the eye, and the anal commencing before the gill-opening. Seven species.

GENUS V. Sternarchus, Schneider. Having a small normally formed caudal fin. A crowd of teeth on the pre-maxillaries, and two rows of recurved ones on the mandible; no tooth on the symphysis. Head and body laterally compressed, the former naked, the latter covered by the lateral line of dorsal scales; the branchiostegals ray, which, in the living fish, lies in a furrow and is kept firmly there by the dermal mucous (this ray is homologous with the fishy fin of the Salmonidae); anus before or under the eye; eye shining through without a lid. Nostrils like small pores. Four branchiostegals in the gill membrane. Three species. The species of this family are so numerous, and many of them are so much alike, that much confusion prevailed respecting those described by the older authors and the many nominal ones recently introduced into our lists by modern ichthyologists who were not in circumstances that enabled them to profit by the examination of specimens preserved in rich museums. M. Valenciennes has thrown a flood of light into the darkness that previously existed; and it is on his labours that we almost solely rely in our notices of the families described in the *Histoire des Poissons*, subsequent to the death of his illustrious predecessor, Baron Cuvier. He has made use of the varieties of den- tition, so great in this family, to characterize his groups; also of the position of the ventrals and of the length of the anal. The comparative length of the mandible has also been taken into consideration by him; in most it projects beyond the snout; a second group is characterized by the snout, owing to the elongation of the nasal, projecting beyond the pre-maxillaries; which, then, instead of crossing the upper edge of the orifice of the mouth transversely, descend on the sides. In some, the maxillary is prolonged far beyond the corner of the mouth. There are diversities also in the fins; in certain species the anal and caudal are united; and in some, a greater or smaller number of the rays of the pectoral are prolonged into slender-jointed filaments; others again have the anal and caudal united, while the form of the mouth varies. We can notice only a few of the species of this family.

*Clupea harengus*, Lin. (The Herring.) The investiga- tion of the habits of this fish has not received that attention which its importance as an article of food to the inhabitants of this country demands; and there are several circum- stances respecting its economy which still require farther examination. It is generally believed that the Herring in- habits, in winter, the depths of the Arctic Ocean, or other seas in northern latitudes, and that during the rest of the year it makes migrations southwards. In summer and autumn it appears on the north and west coasts of Europe in immense shoals, and about the same season it arrives at some parts of the coast of America and Asia. It has been supposed that those coming from the north divide into two detachments, one of which proceeds along Newfound- land to America, the other along Norway to the south of Europe; and that one subdivision of this second detach- ment goes up the Baltic, while the other proceeds along Great Britain, Ireland, Germany, and France, as far as the western coast of Spain.

This is the description of the annual migrations of the Herring given by Pennant; but some doubts have been entertained as to its accuracy, from the circumstances,—1st, That while in some places the Herrings do not make their appearance for years, in others they are taken in abundance all the year round; and, 2d, That they have never been observed on their return northwards. Other naturalists suppose that they come merely from the deep into shallow water during the spawning season, and that in so doing they do not make any very lengthened journeys. In truth, we are not as yet furnished with sufficient data to decide the question; but, in the meantime, we do not feel in- clined entirely to reject the generally received opinion, that the Herrings migrate from north to south in summer and autumn.

In migrating, the Herrings proceed in vast troops,—so great, indeed, that the sea is sometimes covered with them for miles, and that they have even been known to be stranded or crushed in immense quantities in confined bays, or when thrown by the wind or by currents upon the shore. The shoals are said to be generally preceded sometimes for days, by one or two miles. The largest generally go first, to act in some measure as guides; and as they proceed onwards, immense numbers fall an easy and unresisting prey to rapacious birds, or to their own not less rapacious kindred of the sea.

It is generally believed that the Herrings captured far north are larger, fatter, and of a better quality than those of the south; and for this reason, in the month of July, our fishermen go out to meet the shoals as far as Orkney and Shetland. The greatest number are taken on the coasts of Norway and Sweden, in the first of which countries it is said that about 400 millions are taken in one year, and sometimes 20 millions in a single fishery. The inhabitants in the neighbourhood of Gothenburg, in Sweden, take as many as 700 millions in a year. Herrings are fished also in great quantity in this country, Germany, France, Hol- land, the United States, and Kamtschatka.

The average size of the Herring is stated to be about ten inches. According to Dr Knox, the females are consider- ably larger than the males; the largest female he found on the east coast of Scotland measuring eleven inches, the largest male nine inches and a half. It does not appear to be precisely known at what age they attain their full size.

Considerable doubt has at all times prevailed regarding the food of the Herring. They were generally stated to live on small crabs and fishes, and on a minute crustaceous animal named by Fabricius *Astacus harengum*. But this was chiefly matter of supposition; for most practical fisher- men described the stomach of the fish when in good state as quite empty, or, at most, as containing a little brownish mucus; and it has appeared difficult to reconcile the fact, that it is when the stomach appears thus empty that the fish is in its best condition, viz., fullest, with the finest fla- vor, and most capable of keeping,—with the notion, that when it appears upon our coasts it has quitted its natural feeding ground, and has been longer and longer in a state of starvation the more southern the latitude in which it is found. Dr Knox's interesting observation, that the prin- cipal food of the Salmon and Vendace consisted of minute crustaceous animals, led him to examine carefully with the microscope the brownish matter contained in the alleged empty stomachs of the Herring; and he then formed the opinion, that this matter consisted of the debris of a very minute entomostracous animal.

It is well known that the Herrings caught upon the east coast of Scotland are much inferior to those taken on the west coast, and more particularly to those of Loch Fyne, and other lochs of Argyleshire. Dr Knox states that the Herrings taken near the Firth of Forth in July are foul, or are engaged in spawning, while those of the west coast, in the same season, have the organs of reproduction very slightly developed; and he conjectures that that species of crustacean animal which forms their appropriate and most favourite food may exist abundantly in the bays on the west coast of Scotland, and either not at all, or not in sufficient quantities, along our eastern coasts. It appears to be chiefly after these fishes have been absent for some time from their proper feeding places that they eat marine worms and small fishes; and when so feeding, they lose much of their flavour, and run rapidly into putrefaction after being captured. The time of spawning seems to vary considerably, both in the same and in different districts; so that we may have spring, summer, and autumn herrings, as we know they have in some parts of the Baltic. Dur- ing the spawning season they are seen to rub their bellies against the rocks or sand. As many as 68,606 eggs have been counted in one female. The young do not accom- pany the larger herrings in their migrations. M. Valen- ciennes, after reviewing many facts collected by different observers, comes to the conclusion that the Herrings are not nice in their selection of a spawning place, depositing their eggs at the bottom of the sea, sometimes on sand, sometimes on naked rocks, occasionally in sub-marine meadows, in the eddies of currents, at the mouths of rivers, or in the sea far from the shore where the water is tranquil. They change their places of resort, occasionally wholly deserting their former haunts. For a full account of what is known of the economy and habits of the Herring and its fisheries, we must refer to the *Histoire des Poissons* (Cuv. and Valen.), vol. xx., and to the article *Fisseries* in this Encyclopedia. The Herring fishery of France, carried on by the inhabitants of Normandy, dates as far back as A.D. 1030, according to documents still preserved. That of England has been traced to a still higher date; it is named in the records of the Monastery of Evesham as a source of revenue in 709 A.D.; and in the annals of the Monastery of Barking, the tax levied upon it is called Herring-silver. In Iceland the Herring fishery seems to have been so important at an early age, that the word *sild* (Herring) enters into the composition of the names of many mountains in that island.

*Harengula sprattus*, Valenci., is the Sprat, so abundant on the English coasts at certain seasons, and from its cheapness is an aliment that serves to vary the diet of the poorer classes. It is the *Spretté-sild* of the Danes, many of whose sea-terms and names of fish and implements for fishing, have been preserved with slight alteration in the north of England and Scottish lowlands. A second species is named *Blanquette* by the French in the Mediterranean, and is so like the Sprat that most ichthyologists have confounded the two. *Rogentia alba*, Valenci., is the renowned "White-bait" with which our ministry always regale themselves after winding up their parliamentary labours for the session. Mr Yarrell's able account of it exhausts its history, and need only be referred to here. *Alausa vulgaris*, L'Aloise of the French, and the Shad of the English. Ausonius of Bordeaux, who flourished A.D. 380, in his poem on the Moselle, mentions the Shad as the food of the common people—

"Stridentesque focis opona plebis alausa."

*Alausa pilehardus*, the Pilchard so plentifully caught in its season on the Devonshire coast, and consumed by the inhabitants of that county in pies, in which the heads of the fish protrude through the crust, to denote the nature of the contents. It is the Sardinia of the Spanish peninsula and Mediterranean Sea, and the Celan of the French fishermen. Its fishery is important to the inhabitants of the south of England, Brittany, Portugal, and Galicia. At St Ives in Cornwall, 250,000 have been caught in a single draught, and few who have visited Lisbon but must have admired the fleets of sharp-built latine-sailed boats, named "Bean-cods," issuing from the Tagus, to carry on a fishery so invaluable to a Roman Catholic population.

*Engraulis encrasicolus*, the Anchovy, is another celebrated member of this family, very plentiful in the Mediterranean, and found on the coasts of Greenland, Jutland, and the Baltic; it is occasionally caught in the Irish Channel, but is rare on the English side of the British Channel, though it has been taken, according to Mr Yarrell, on the Hampshire coast, and on Dagenham Breach below Blackwall. Formerly it was more abundant in the British seas, and several acts of parliament passed in the reign of William and Mary regulated its fisheries. It was also a century ago plentiful on the coasts of Brittany, though by no means so now.

Under the head of Fisheries the statistics of the deep-sea fisheries of Great Britain are fully entered into, and their great importance as a branch of national industry shown in detail. There are, however, wide fields for the employment of British capital in the East, where the supplies are inexhaustible, and the demand in the China and other markets exceedingly great. *Colia Playfairi* is represented by fig. 17. The *Alausa toli* (Cuv. and Val.) is the subject of a very extensive fishery on the coast of Sumatra, for the sake of its roes, which are salted and exported to China, the dried fishes themselves being sent into the interior of Sumatra. The fish is named "Truhi" in the Malay tongue, is about 18 inches long, and between fourteen and fifteen millions are caught annually with very rude tackle.

Another of the Herring tribe, the *Engraulis Brownii*, is exceedingly numerous at all seasons in the Straits of Malacca, and at the mouths of the Ganges. From it a delicious condiment named "Red fish" is prepared by adding vinegar made of the juice of the Cocoa palm, ginger, black pepper, and powdered red-rice to the salted fish. *Dussumiera acuta* and *Clupeonita perforata*, also members of this family, are taken at Penang, and brought to table under the denomination of "Sardines." They are said to have a delicate flavour; but the *Meletta venenosa*, which occasionally visits those seas in shoals, is poisonous, and has produced death when eaten by mistake for the "Sardine." The poisonous fish has red eyes. These facts are from Dr Cantor, whose work on the Malayan fishes goes more into detail.

**Sub-Order III.—ABDOMINALES.**

**Family I.—HETEROPYGI.**

Tellkampf characterized this family from the blind fish found in the Mammoth Cave of Kentucky, *Amblyopsis speleae*. It is distinguished from the other *Ptychopteridae* by the position of the vent, which is three times before the ventral, and small eyes covered with skin; it possesses no accessory gills, no adipose dorsal, a simple swim-bladder; a caecal stomach; and pancreatic ceca. The very forward position of the anus occurs in other families, notably in *Gymnuridae*, also in several of the *Tunicidae*, and *Lophididae*. Dr Wyman, on examining the fish, could discover no ocular spot, but a pretty large optic nerve. Agassiz is inclined to consider the *Amblyopsis* as an aberrant form of the *Cyprinidae*, but until he has investigated its embryology he reserves his decision.

**Genus I. AMBLYOPSIS.** Characters those of the family.

**Genus II. CHOLOSASTER, Agassiz.** Habit that of *Amblyopsis*, but it has eyes; it has likewise a guttural anus, but wants the ventrals wholly. There are two horn-like processes on the snout. One species, *C. cornutus*.

**Family II.—APHRODEIRIDE, Bon.**

This family, founded on a single species, is placed by the Prince of Canino in the order of *Heteropygi*, comprising *Amblyopsis* also. Both agree in the guttural position of the anus, but M. Valenciennes places *Aphredoderus* among his Percoids, near *Pomacis*. The characters of the family are those of the genus.

**Genus I. APHREDODERUS, Lesueur.** Scaly *Anchopteryx*, with a single dorsal on the summit of the fusiform body; pectorals and subbranchial or abdominal ventrals; anus before the pectorals, under the gill-openings; branchiostegals six. No spine in the ventrals; a spinous point to the operculum, and crenatures on the subbranchial scale bones. Scales ctenoid. Stomach very small, sphincter gut running into the pylorus; muscles of the abdomen to the anus, which opens just behind the edge of the branchiostegal membrane. Air-bladder large, simple, with round ends. Mills communicating with the anal opening by a long canal which follows the intestine. One species. Lake Pontchartrain.

**Family III. CLUPEIDE, Valenci.**

Scaly fishes, without an adipose fin. Body generally elongated and very much compressed; belly thin and trenchant, frequently denticulated by the edges or points of a series of dermal bones. Scales always present on the body, but easily detached. No spines in the fins; ventral fins nearly in the middle of the body; dorsal fin always solitary; moderately long premaxillary bones conjoined with the maxillaries to form the upper border of the mouth (this character they possess in common with the *Salmonidae*); maxillary composed of three pieces easily separated.

Gill-openings very large; rakers of the branchial arches long, and prolonged into the branchiostegals; branchiostegal gills present. Ribs long, and with their epipleural spines very slender; the latter diverging from the parapophyses and neurapophyses of the vertebrae, as well as from the ribs; points of the ribs connected with the dermal osseous scales on the edge of the belly. Stomach caecal, often fleshy; pyloric ceca numerous and long. Ova (roe) very numerous, and... Analytical Table of the Clupeide (Dunn.)

Mouth large.

Anal separated from the caudal.

Ventrals conspicuous.

Ventrals none, or scarcely visible.

Anal coalescent with the caudal.

Mouth of moderate size, or small.

Teeth visible on the jaws.

Teeth on all the oral bones.

Teeth on the upper jaw and mandible only.

Teeth on the upper jaw, mandible, and pterygoids.

Teeth on the tongue only.

Teeth on the tongue and palatines.

Teeth on the tongue and pterygoids.

No teeth in connection with the oral bones.

Dorsal with all the rays connected.

Dorsal with one isolated ray.

No teeth on the vomer, nor jaws, but on the other bones.

No teeth on the vomer only.

Anal short, far back.

Anal long.

Ventrals none.

Ventrals present.

Genus I. Clupea, Valenc. Small pre-maxillary teeth; crenatures on the maxillary so fine as to be discoverable rather by the touch than by the sight; fine teeth also on the symphysial portion of the mandible which projects farther forward than the upper jaw; a longitudinal row of larger teeth behind the vomer; a similar one on the tongue; two or three very small deciduous teeth on the external edge of the palatines. Body elongated; back rounded; belly more or less compressed or concave according to the size the roe or melt has attained. Sixteen species.

Genus II. Sardinella, Valenc. Teeth on the palatines, entopterygoids, and tongue; none on the vomer, pre-maxillaries, maxillaries, or mandible. Specific characters derived from the forms of the gill-cover or other external part. Seven species.

Genus III. Harungula, Valenc. Teeth on the jaws, tongue, palatines, and entopterygoids; no vomerine teeth. Ten species.

Genus IV. Pellona, Valenc. Dentition of Harungula. Body very much compressed. Ventrals before the dorsal; anal long and broad; a row of the belly strongly denticulated behind the ventral, their first ray strong, though pointed, and long. Sixteen species.

Genus V. Pristigaster, Cuv. Apodail Pellona. Air-bladder various; large and forked behind in some species. Four species.

Genus VI. Roegena, Valenc. Teeth on the vomer, palatines, entopterygoids, and tongue; teeth also on the jaws, but scarcely visible.

Genus VII. Clupeonia, Valenc. Teeth on the tongue and entopterygoids only; jaws, vomer, and palatines edentate. Five species.

Genus VIII. Spratella, Valenc. Teeth on the palatines and tongue only. Two species.

Genus IX. Kowala, Valenc. Teeth on the jaws and entopterygoids only; teeth on the tongue, vomer, or palatines. Form of Spratella. Two species.

Genus X. Meletta, Valenc. A rough band on the tongue; no other teeth. Ten species.

Genus XI. Alausa, Valenc. Teeth on the jaws deciduous and very small; no other teeth; a notch in the upper jaw. Air-bladder simple, pointed at both ends, and not extending before the third vertebra; air duct entering the conical point of the exca stomach. Twenty-two species.

In the preceding genera the mandible is longer than the upper jaw.

Genus XII. Engraulis, Valenc. Mouth large, almost projecting. Nasal bone advancing before the jaws, concealing the small pre-maxillaries; maxillaries slender, not prolonged behind the mouth; vomer, palatines, and entopterygoids narrow, sustaining teeth sometimes very small. Gill-openings large. The species may be divided into two groups, by the elongation of the upper ray of the pectoral, or by the absence of that character. Twenty-three species.

Genus XIII. Coilia, Gray. Maxillaries large, their posterior ends passing the gill-opening. Dorsal far forward; upper rays of the pectoral prolonged into slender filaments, and divided nearly in the middle. Tail generally much compressed, tending to a point, with a long lateral line united to the dorsal; there is an exception to this character in a species which has the tail abbreviated, and the caudal wide and rounded. In other respects the genus corresponds with Engraulis. Six species.

Genus XIV. Odontognathus, Lac. (Gnatholepis, Schn.) Body greatly compressed; belly trenchant and very strongly denticulated, from the throat to the anus. No ventrals; dorsal very small, far back on the tail; anal very long and low, extending to near the forked caudal; pectorals moderately long. Mouth small; mandible passing the upper jaw, which is truncated, with the small pre-maxillaries lying transversely; maxillaries long, wide in the middle, projecting backwards beyond the mandibular joint. Teeth on the jaws, palatines, entopterygoids, and tongue; none on the vomer. One species.

Genus XV. Chatoesius, Cuv. Mouth small, edentate; pre-maxillaries small, with a medial notch which receives the symphysial apex of the mandible and a fibrous lip, that runs backwards from it along the whole edge of the maxillary, the latter articulated to the nasal behind the pre-maxillaries; first branchial arch uniting above the pharynx with its fellow, and sending a curious pectinated branch forwards beneath the roof of the mouth. Body in general high, oval, and short; belly strongly denticulated. Pectorals and ventrals small; first ray of the dorsal frequently prolonged. Stomach muscular; pyloric ceca very numerous, united by cellular tissue into a glandular mass, which fills great part of the belly; ova not included in a sac, but dropping into the general cavity of the abdomen. Twelve species.

Genus XVI. Amlogaster, Bleeker. Small pre-maxillaries; the maxillaries constituting most of the upper half of the mouth. Body elongated, compressed; belly rounded, without serratures. No teeth. Head naked above; eyes half covered by a membrane; cheeks venous; five branchiostegals. Indian Ocean.

Salmon Family.

The progress of Ichthyology in the last half century has been rapid, as might be expected of a science which had been previously greatly neglected, but whose importance was at length acknowledged. The old generic groups of fishes were first characterized as families, and afterwards having, by the discovery of new forms diverging more or less from the characters of the typical species, and having, moreover, been found in many instances, by the more correct investigations into their structure that were instituted, to include heterogeneous assemblages, were broken up into several genera, families, or even into groups of a higher order. The genus Salmo of Artedi is an example of this. That ichthyologist included in this group all fish which have from twelve to nineteen branchiostegals, teeth on the jaws, and a dorsal standing over the ventrals, with an adipose fin on the tail. Linnaeus modified this classification somewhat, and at length three great families have grown out of the single genus Salmo, one including all the Salmonoids, with the cheeks or the whole head covered with scaleless integument, being the group comprised in our table under the name of Salmonidae. The Characinii, a second family of fishes formerly associated with the Salmon, is characterized by the small number of its branchiostegals, a very small mouth, great variety of dentition, almost always in many rows, but rarely with any on the tongue, and with a divided air-bladder. The Scopelidæ is the third family of this stock, being distinguished from the others by the maxillaries not forming part of the orifice of the mouth. Some smaller detachments have also been made, as the Erythrinidæ and Macrodon.

Salmo, Cuv. The fishes which constitute this genus are of great importance, and are by far the most esteemed and valuable of all those which inhabit the fresh waters. The value of the fisheries, with the number of men engaged in them, is very great, and the expense of the mate- Salmo solar, or common Salmon, a species which likewise occupies the foremost place in the estimation of both sportsman and epicure. The Salmon is a fish of great elegance, combining a form fitted alike for strength and swiftness; and its depth and thickness, while in good condition, are so proportioned to its length as at once to convey the idea of a pleasing symmetry. The body above is of a rich bluish or greenish gray, changing below to silvery, sprinkled above the lateral line with rather large sub-cruciform black spots, a few of which at the shoulders generally extend below the line. The characters which distinguish it from its British congeners are the different form of the opercular bones, which show a rounded outline to the posterior edge of the gill-covers, the longest diameter of which to the nose would be in a line through the eye, while in all the other British migratory species the same line would pass much below the eye. The black inner surface of the pectoral fin is nearly a constant mark. The tail is forked in the young state, but fills up to a nearly square outline in the adult.

The common Salmon inhabits the seas around Great Britain, and extends to the north of Europe and to Asia. It generally delays entering the rivers in great numbers until the streams become somewhat swollen by rains, although in the larger rivers there may be said to be a limited daily run. When the flood has fairly mingled with, and to a certain extent has saturated the estuaries, the rush of fish is often very great, especially if there has been a continued tract of dry weather. In the latter case they collect at the mouths of rivers, and are seen and often taken in vast numbers; but they do not then attempt an ascent, deterred perhaps by the clearness of the stream, or by some instinctive feeling that the water would yet be deficient to carry them through. As the fresh approaches, however, an increased activity may be perceived; and, as far as we can judge, the change is probably indicated by the nostrils receiving a sense of the mixture of the waters, by means of the large ramification of nerves with which they are supplied; and to this same sense may perhaps be attributed the singular fact of the greater proportion of Salmon returning to the very streams in which they were spawned. The fish, on entering the river, rush forward as long as the flood continues, seldom resting in their course during the time that the water continues discoloured. From ten to twenty-five miles daily is the rate, as far as can be ascertained, at which they are supposed to travel.

In their more lengthened courses, where the rivers are deeper and the interruptions less frequent, the rate at which Salmon travel is probably more rapid. Our common kind (Salmo solar) makes its way by the Elbe into Bohemia, and through the Loire as far as the environs of Puy, in the ancient Velay. We also know that it works its way up the Rhine, and visits a portion of the rivers of Switzerland, although the irresistible torrent of the Falls of Schaffhausen prevents its ingress to any part of the basin of the great Lake of Constance. It is an entire mistake to state its occurrence in the Persian Gulf; and equally absurd to say that, unrepelled by the gloomy terrors of a subterranean journey, Salmon from the Gulf, adorned by the fanciful Persians with rings of gold and silver, find their way into the Caspian. The non-existence of the supposed communication, is of itself a pretty sufficient barrier, even did no other exist in the laws of nature, and were light and atmospheric air dispensable. M. Valenciennes states that it belongs not only to France, England, and Germany, but to Schleswig-Holstein, Mecklenburg, Scandinavia, Iceland, and Greenland. It exists also in Labrador and Canada, and down the American coast to the Connecticut River, in latitude 41°3'; and either it, or a species so nearly allied to it as not to be distinguishable except by close comparison, abounds in the Arctic Seas washing the northern shores of the American continent. It does not frequent the rivers falling into the Mediterranean, though Dr Davy informs us, on the authority of an intelligent observer, the clerk of the market at Malta, that a stray Salmon was once caught at that island, and brought to the market for sale. During nine months residence at Constantinople Dr Davy paid frequent, almost daily visits to the well-supplied fish market of that city, but never saw either Salmon or Trout among the great variety of other fish that were there for sale.

In our lower and clearer waters, however, they travel at a much slower rate than that above alluded to—resting for some time in the pools by the way, and now and then taking a regular lie in some chosen spot, which they will return to daily as long as the river continues unfitted for their progress. Upon the least accession, however, to the water, either directly or from some swollen tributary, they are again upon the alert; and it is often felt by them several hours before the quickest or most experienced human eye can perceive a rise upon the river. Having ascended to a considerable height, they remain more stationary, and proceed more slowly with the subsequent floods, till the spawn increases in size. This increase, if not influenced by, is at least so connected with, the commencement of the colder weather, as then to proceed at a more rapid rate. As the spawn advances, the symmetry of the form is disfigured; the female becomes disproportionate; large, the colours lose the brightness of their silvery tints, and become dull and gray. The male becomes thin upon the back, the nose elongates, and the under jaw turns up in a large and strong hook, which enters a hollow in the nose before the pre-maxillary bones. The colours and markings become brown and red, those on the head and gill-covers being particularly brilliant, and disposed in lines almost like the marking of a Sparus. In this full breeding dress the male and female seek some ford or shallow stream, and commence to excavate a trench or furrow (chiefly by the exertions of the female). In this the spawn is deposited, and impregnated at the same time, and finally covered with gravel by the exertions of the fish. The furrow is generally from six to nine inches in depth; and when the spawn has appeared to be covered beyond that depth, this has occurred from some other circumstances—such as the stream or floods having carried downward additional masses of gravel, &c. After this great effort has been accomplished, both sexes are reduced to a state of remarkable emaciation. The elongated nose, and hooked jaw, and brilliant colours, are almost immediately lost; the old scales are cast, and the fish retire to some pool to regain their strength and complete their new clothing. They finally redescend to the sea by easy stages, where their former condition and silvery lustre are regained, their strength invigorated, and all their functions so repaired as to enable them ere long to renew their visit to the flowing streams, again to multiply their race.

The ova continue covered by the gravel during the winter, and begin to vivify from about the end of March to the commencement of April. The fry remove from under the gravel when nearly an inch in length, with the ovum still attached; and at this period, if the spawning bed or furrow be turned up, it will appear in motion. We refer to the article Fisheries for the details of Mr Shaw's observations, which prove that the young fish or Parr may remain a full year in the fresh water. On the eve of descending to the sea, the Parr assumes a more brilliant dress and becomes a Smolt. At this time it is from four to six inches in length, of a greenish gray above, silvery below, the scales extremely delicate and very deciduous. From the time the Smolts reach the sea, for two months or ten weeks, we lose sight of them, and can only infer their growth from the fact, that after the lapse of that period we find them again ascending the rivers with a weight of from two and a half to four pounds. They are then known under the name of Gilse or Grilse; and their size, as they ascend from the sea, increases with the advance of the season. The Grilse which thus ascend spawn during the ensuing winter, and are then entitled to the name of Salmon. Descending in a weak state (as before mentioned), they return again in the summer of the following year, as fish of from ten to fifteen pounds weight, according to special circumstances. A third year would still increase their weight, as would several ensuing seasons, till the attainment of an enormous size. Pennant, for example, mentions a Salmon which weighed seventy-four pounds; and although we now regard with something of wonder a fish which weighs even the half of that amount, yet there is no doubt that not many years ago Salmon of forty pounds were much more frequent than in these degenerate days. The absence of Salmon of the largest class from many of the Scottish rivers, where they formerly abounded, is in fact owing to the injudicious perfection of our fisheries, which occasions the constant capture of the species in the state of Grilse, or other early condition; and the chances are by consequence greatly against any individual escaping the various dangers by which it is environed, for such a succession of years as is likely to admit of its attaining to its full dimensions. The destruction by poachers, in the higher parts of the rivers, of the large enfeebled Kelts, or fish which have completed their spawning operations, is also extremely prejudicial; for these individuals (almost utterly useless as food at the time alluded to) would, if allowed to descend to the salubrious sea, ere long revisit their native streams, greatly increased in size, and full of health and vigour. A Salmon above fifty pounds weight was taken, in 1835, at the mouth of the Leven in Dumbartonshire. The general capture that season was very great in Scotland. Nearly 800 were taken at one haul in a bay of the island of Islay; and our calculation, from accurate data, is, that for some time, about a hundred thousand Salmon (including Grilse) were then shipped in Scotland weekly from our eastern ports alone. A friend of our own lately saw a Salmon of sixty-one pounds weight on a fishmonger's stall in London; and as these sheets are before us, we read in the Times of July 15, 1856, that a Salmon was caught at Chanonry Point, Moray Firth, Fortrose, on the 10th, which weighed sixty-two pounds. It was sent to London, and purchased by Mr Barton, fishmonger, of Bishopgate Street. Similar causes have diminished the Salmon in the northern parts of the United States of America. Hudson, in 1609, when sailing up the river that bears his name, "saw great store of Salmons." Now a solitary Salmon straying thither is a rarity.

Dr Davy has for some years been in the habit of recording his observations on the Salmonidae, and has made, with his usual accuracy, a series of important experiments likely to throw much light on the distribution of species. From these, he concluded "that the ova of the Salmon, in an advanced stage, can be exposed to the open air, if dry, but a short time, at ordinary temperatures, without loss of vitality; but for a considerable time, if the temperature be low and if the air be moist; the limit in the former case not having exceeded an hour, whilst in the latter it has exceeded many hours. The vitality of the ova was as well preserved in air saturated with moisture, as it would have been had they been kept in water. It was also preserved even when the ova were included in ice, but if they were exposed to a temperature many degrees below the freezing point, probably effecting their congelation, they were deprived of their vitality. Both the ova and young fish were capable of bearing a temperature of about 80° or 82° in water for a moderate time with impunity, but not without a loss of life; at a higher temperature than 84° or 85°. A degree of saltness of water nearly equal to that of sea-water proved speedily fatal to the ovum of the Salmon and to the young fish; the same effect was produced on the young fish by brackish water of specific gravity 1016, but in a longer time; and when the solution is so diluted as to be reduced to the specific gravity of 1007, the advanced ovum may be hatched in it, and the life of the young fish may be sustained in it for many days but with diminishing power."

From Dr Davy's excellent paper, the fact of temperature having a still higher influence on the distribution of species of fish than on the higher animals is apparent. An anadromous fish must have its range restricted not only by the temperature and suitableness in other respects of the affluents of a river in which it deposits its roe, but also by the nearness to the equator of the mouth of that river. We may, therefore, find Salmon in the streams flowing down the northern side of a great watershed while they do not exist on the southern side, though the feeders of both river systems interlock at their sources. This Dr Hooker found to be the case with the Trouts, which are confined to the northern face of the Himalaya range. Dr M'Clelland has described a species, S. orientalis, which inhabits the affluents of the Oxus. The parallel of 45° N. Lat. may be roughly considered as the southern boundary of the common Salmon in Europe, overlooking the feeders of the Atlantic rivers which rise to the southward of that latitude; and the parallel of 41° may be taken as the limit in America, adverting to the fact that the mean annual heat in a given parallel of the latter continent in the temperate zone, is from 8° to 15° of Fahrenheit lower than the parallel in Europe. The mean temperature of the year on these parallels lies between 46° and 52° Fahrenheit, and the mean heat of the hottest month between 60° and 68° Fahrenheit. The heat of the waters of the rivers frequented by the Salmon will, of course, vary much less than that of the atmosphere, and fall far short of the hottest months.

Ausonius, in his poem on the Moselle, which we have already had occasion to quote, says of the Salmon—

"Nec te paniceo rutilantem viscere Salmo transferim,"

contrasting it with the characters of two other members of the family, the *Fario* and *Salar*, by equally descriptive lines which will be quoted when these fish are noticed.

*Fario argenteus* of Valenciennes, "Truite de mer ou Truite argentée," is stated by him to be identical with the *Salmo Cumberland* of Lacépède, and with the Salmon-Trout of Yarrell, the *S. trutta* of British ichthyologists. It is also according to the last-named author, the "White Trout" of Devonshire, Wales, and Ireland, but is more abundant in the rivers of Scotland, where it is named the Sea Trout. In the Nith it is taken in quantities, associated with young of other species, and sold, together with them, under the name of "Hirling;" but on attaining the larger size of several pounds weight, it is distinguished as the Sea Trout. Its head and dentition are correctly figured in plate 92, fig. 1, A and B of the *Fauna Boreali Americana*. The Hirling has been named *Salmo albus*, and locally, "Whitling." In its largest state, or as known under the specific title of *S. trutta*, it enters the rivers from two and a half to six pounds weight in the end of May. It is of an elegant form, and possesses all the symmetry of the Salmon. The head is small, the back remarkably broad when viewed from above; the tail slightly forked, and wide at the extremity of the web; the colour above greenish, inclining to bluish-gray, lower parts of the clearest silver; body above the line spotted, as in *S. eriox*, with large, deep-black spots, but generally much fewer in number. The flesh is pink, richly flavoured, and much esteemed for the table. It ranks next to that of the Salmon, and by many is esteemed more delicate than even that prized species. The *S. albus*, or smaller and younger state in which it is found, is very nearly of the same proportion, form, and colours. They approach the mouths of the rivers in the end of July and commencement of August, in immense profusion, and immediately enter the fresh waters, where an angler may take almost any quantity without the exercise of great skill. In the North they form a perquisite to the taxmen or kayners of the Salmon fisheries—above a thousand being sometimes taken at a sweep of the net. In the Solway they are taken in equal abundance in houses of the stake-net, covered for the purpose with net of a small mesh, and are then carried to the various country markets, and during the height of the run, to the villages, in cart-loads, for sale. The flesh of this smaller fish (whether species or variety, as the case may be) is also pink, and delicately flavoured. Its food is likewise the same as that of the larger kind; in the sea small Crustacea (*Talitrus locusta* being a favourite and common food); in fresh water, aquatic insects, worms, minnows, or other small fish. They appear also to spawn rather earlier than the Salmon, and after the same manner. The colours of both sorts during the breeding season are deep-grayish black, slightly tinted with brown in the males; and at this time they offer a most marked contrast (being black and lean) to the symmetrical form and brilliant silvery tints of their perfect condition. It is of this fish that Ausonius, in his poem on the Moselle, already quoted, says—

> Teque inter species geminas, nequamque, et utrumque, > Qui nequum Salmo, nec jam Salar, ambiguumque > Amborum medio Fario intercepte sub auro!

thus well expressing the doubts still entertained after a lapse of fifteen hundred years.

*Salar griseus aut cinereus*, Willanby and Ray. We have adopted these names as not subject to the same misapprehension with *eriox*, which our modern British ichthyologists have borrowed from Linnaeus, but M. Valenciennes, after much investigation into the synonyms of the *Salmonidae*, says that it is altogether impossible to discover at this day the species which the Swedish naturalist had in view when he characterized *eriox*; and M. Valenciennes has not recognised the *S. griseus* in the French rivers. The English fish is named the Bull Trout, the Gray Trout, the Whiting, and the Round-tail, according to the district in which it is taken. In Wales it is called the Sewin; and Donovan has given it the specific appellation of *Cambricus*, but it is often confounded in the markets, and even by fishermen, with the *Fario argenteus*. The same thing occurs in Dumfriesshire, the young of the two species on their first return from the sea being sold under the name of "Hirling." They come up the river Nith from the Solway Firth with the tide, and are very plentiful for a short time. The best flavoured Hirlings of the two are the yearlings of the *Fario argenteus*; but the flesh of the *Salar griseus* is also red on coming from the sea, and seems to be more juicy and rich than that of older Bull Trouts. The *Salar griseus* reaches a weight of twenty-five pounds. It is thicker in proportion to its length than the Salmon; the fins are much more muscular; the tail particularly so, and perfectly square at the end in all the stages of growth, while the distance between the two extremes of the web is smaller proportionally than in any of the other species. The head is larger in proportion than that of the Salmon of a similar weight, and the opercular covering is more lengthened. The toothing is very strong. The general colours are—above, grecish gray; the lower parts silvery white; the body above the lateral line being thickly covered with large cruciform black spots. In the breeding fish they assume a much blacker tint than the Salmon, and want much of the red markings. All the under parts, jaws, and cheeks, become blotched with deep blackish gray. The flesh is of a yellowish tint, and is coarse, except in the young state; it has the least flavour, and is consequently less esteemed in the market than any of the other species. The hook of the under jaw of the male does not become so elongated as in the Salmon. The old fish commence to enter the rivers about the end of July, and appear to deposit their spawn and return to the sea about a month earlier than the Salmon. The young fish, of from two to three pounds weight, and in this state known as Whittings, enter the rivers about the beginning of June. In all its states it is a very powerful fish, and feeds voraciously and indiscriminately. When hooked it springs repeatedly from the water, and runs (to use an angler's expression) with extraordinary vigour to free itself. The River Tweed and its tributaries, and the Nith, the Annan, and Esk, which fall into the Solway, are the principal Scottish localities for this fish.

*Salmo hamatus*, Cuv., is described at length in the *Histoire des Poissons*, and reasons assigned for dissenting from the opinion of Agassiz who holds that it is the male of *Salmo salar*. *Salmo hucho* is the Salmon of the Danube, where it attains the weight of 30lbs, and it is reported, even of 60lbs. Gesner says that its flesh is white, and less agreeable than that of the common Salmon; while Corbine says that it has a good flavour, but is a little dry. The *hucho* spawns in June, in hollows excavated in the gravelly bottoms; the male and female working together and hiding themselves in these hollows from the nets of the fishermen. Mr Reissinger has verified these observations in Hungary. In Galicia this fish is named "Reo." It is a mistake to suppose that it is an inhabitant of the British waters. *S. umbra*, a fourth species, is common in the eastern parts of France, in Switzerland, and the Tyrol. It is the *L'Ombre chevalier* of the French, and M. Valenciennes considers it to be identical with the Charr of England, the *S. carpio* of the *Fauna Danica*, and the "Kebleriksoak" of the Greenlanders and of Otho Fabricius; and he quotes, with commendation, Mr Yarrell's figure of the Northern Charr, as enabling him to recognize the species. M. Valenciennes rejects the Linnean name of *alpinus*, applied by most English ichthyologists to this species, as he says that referred to a different species. He retains, however, the name of *S. salvelinus* for the other English Charr, though that also was differently used by Linnaeus; but it is the fish Salmo umbla is abundant in the English lakes, and in the greater number of those in the north of Scotland, when of any considerable extent; but more seldom seen there, from the absence of the practice of netting, and the general unwillingness of Charr to take a fly or bait. This fish is of great repute in the Lake of Geneva, and is also found in many of the alpine lakes of northern Europe. The common Charr reaches a considerable size, being sometimes taken in Britain above 2 lbs. in weight, although the more usual weight is under three quarters of a pound. When in full condition, it is a fish of very great beauty, above of a grayish green, shading into the most delicate white on the lower parts, and tinted with a blush which is comparable to that seen on the breasts of some of the gull tribe when newly shot in spring. The body is sprinkled over with pale spots of a considerable size. In this state they remain in the deeper parts of the lakes, and are not frequently taken, although we doubt not they might be so were the practice adopted of hanging a herring-net in the deep water, instead of trying only the winter practice of hauling in shore. We ourselves caught them by the former method, in their prime silvery state, in Sutherland, during the month of June. On the approach of the breeding time, they seek the mouths of the small tributaries, and are taken in vast numbers at the very period when their preservation ought to be most strictly attended to, and when, in truth, they begin to fall off in their condition. At this season the colour of the upper parts is darkened, the fins are very rich, and the sides and belly become of a beautiful and brilliant red, the whole spotted with small marks of a paler tint.

S. salvelinus occurs in Wales; and we have already mentioned (in the article Angling of this work) that both kinds occur in Windermere, to wit, the Charr or Case Charr (Salmo umbla), and the Torgoch or Red Charr (Salmo salvelinus). These are usually thus distinguished—the former, by having the first rays of the ventral and anal fins white; the latter, by having those parts plain, that is, of the same colour as the other rays. A remarkable distinction is also observable in their natural habits,—the Case Charr ascending rivers, and spawning about Michaelmas; the Red Charr depositing its ova along the shores of the lake, and not till the end of December, or the beginning of the year.

The chief feeder, or head stream of Windermere, is composed of two branches, the Brathay and the Rothay, which meet a short way above the lake, into which they speedily pour their united waters. The Brathay is the left-hand branch (as we ascend from the lake), and draws its sources from the mountain vales of Langdale, reaching Windermere without any resting-place; while the Rothay has previously formed and flowed from two consecutive lakes, Grassmere and Rydal. The Charr, in ascending from Windermere to spawn, invariably turn to the left, and ascend the Brathay (though to no great distance), and as invariably avoid the lake-descended waters of the Rothay. They also spawn lower down the lake of Windermere, at the mouth (or a short way upwards) of the stream called Troutbeck, which is also derived from the flow of mountain tributaries, without any lesser or intermediate lake.

Although the art of angling is not immediately connected with the science of Ichthyology; it is, at the same time, evident that the successful practice of that art necessarily illustrates the food of fishes, and therefore makes us acquainted with an important portion of their natural history. For this reason we insert the following memoranda, transmitted to us by Mr John Wilson, jun.:—"The season for fishing Charr (with rod and line) in Windermere and Coniston commences about the end of May, and, I should say, is over by the first or second week in July. Trolling with a smallish minnow is by far the most successful mode of angling for this fish. It may, however, be taken with the artificial fly, the green and gray drake being the favourites. I killed three, one day in May last, with a small red professor. A Bowness fisherman, on the same day, trolling without intermission from six in the morning till six in the evening, killed six and twenty, being the greatest number that has been taken in Windermere, in a single day, by one person, for many years. In Coniston, where this fish is more abundant, I believe it is by no means uncommon to kill three or four dozen in a day. With regard to the size of Charr in Windermere, I should say they average three to the pound. I never saw one that was a pound. Billy Balmer told me that he once saw one that was a pound and a quarter, and that it was the largest ever taken in Windermere." In relation to the same subject, in a different locality, we may also add the following extract from another hand:—"A small red Charr is found in Loch Achilty, Ross-shire, on the property of Sir George Mackenzie. It takes the fly greedily in warm still weather, and, what is singular, during all the summer and autumnal months. I have captured eighteen in a forenoon in July—raising many more. My flies were of various sorts, from a midge to one as large as a sea-trout fly. The water of Loch Achilty is singularly deep and transparent; the soil is rich and loamy, and contains large quantities of imbedded wood—black oak especially. It is supplied by numbers of minute streams, but has no visible outlet, being supposed to discharge itself subterraneously. The Charr found in it average eight or nine inches in length; we, however, caught one much larger. They rise with less velocity than the Trout, and on missing the fly, unless injured, will return to the hook. In Strathglass there is a Loch Bruich, where Charr are caught of a much larger size, but chiefly with the net; except in the month of October, when, as our informant, the Rev. Mr Chisholm, told us, they may be taken in the shallows with the rod, but at no other season."

On dissecting the Charr which we killed last summer in Sutherland, with a view to ascertain their food, we found the stomach usually empty, but the lower part of the intestine filled with green vegetable residuum. This we found to be the remains of the cases of aquatic larvae (Phryganidae), a few of which we discovered in a half-digested state in the upper portion of the intestinal canal.

The true S. alpinus of Linnæus is, according to M. Valenciennes, a Salmon which corresponds perfectly with the figure of the Roëding by Ascanius, and the only species that agrees with the description given in the Fauna Suecica. It inhabits the Norwegian and Swedish waters, and also the rivers of Siberia which fall into Lake Baikal. For the other species of Salmon we must refer to the pages of the Histoire des Poissons.

Professor Nilsson of Lund has investigated the Scandinavian Salmon, and compared them with the original specimens of Linnæus, still in the museum at Lund.

I. TRUTTE, "Lachs" Suecis.

(a.) Teeth in the front only of the vomer.

1. Salmo salar, L.; "Blanklachs" Suecis. (Fauna Bor. Amer., pl. 91, fig. 1. Salmon from the River Urr in Galloway.)

2. Salmo erion, L.; "Graulachs" Suecis. (Fauna Bor. Amer., pl. 91, fig. 2. Head of a Trout from Glamorganshire, in Mr Yarrell's possession, said to be the Sewin.)

(b.) Teeth in one row down the medial line of the vomer.

3. Salmo trutta, of which the following are varieties:—S. ocella, Nilss.; S. truttae, Nilss.; S. fario, L.; S. punctatus, Nilss. II. SALVELINI, "Rothfischen" Seelis; Charr. Anglis.

4. Salmo salvelinus, L.; of which S. pallidus, Nilss., S. alpinus, L., are varieties.

5. Salmo carbonarius, Str., of which S. variegatus is a variety. (Arch. für Naturg. von Troesch, 1849, 310.)

Fario Lemanius, or the Salmon-Trout of the Lake of Geneva, is another fine species of this genus, fully described by M. Valenciennes, and beautifully figured by M. Agassiz.

Salar Ausonii. Under this new appellation, M. Valenciennes, treats of the well-known Salmo fario of authors, the river Trout of England, and the burn Trout of Scotland. Having adopted the word fario for the appellation of a generic division of the family, he has taken a specific name from the author who has so briefly, yet so well, characterized the three members of the family that are the most remarkable for the frequency of their occurrence in the rivers of Europe. The propriety, however, of setting aside a specific name so long established as fario, and so little mistaken, may be questioned.

"Purpureaqua Salar stellatus tergore guttis."

This line which, with others, from the same author, we found in the Histoire des Poissons, and have quoted in preceding pages, gives a neat description of the Trout. One of our own poets says:

"The springing trout in speckled pride, The salmon, monarch of the tide, The ruthless pike intent on war, The silver eel and mottled parr."

thus singling out three of the salmon tribe that frequent the Leven, flowing over its smooth, round-pebbly bed.

This lovely Trout is most extensively distributed over the whole of Northern Europe, being found in every burn and tarn, in every lake and river. It may be also said to be one of the most pleasing in its appearance; and, when newly taken in "golden glory" from some translucent stream, is exquisitely beautiful. The variation of the tints of the ground colour is infinite; yellow, however, is the most predominant, varying to the most brilliant orange; while at other times the ground colour of the body runs from a dark-greenish black to violet, in most instances numerously spotted with black and red. Sometimes, however, the black is alone present in the form of large round spots, placed in a pale circle, but in all cases beautifully relieved, and breaking up the uniformity of the other colours. In a few instances the spots have been observed to be wanting altogether. One cause of the variation in the Trout, is the difference of food; and, according to every information we possess, those which feed on fresh-water shells and Gammari (screws, or fresh-water shrimps, as they are sometimes called), are of the most brilliant tint, and also of the finest flavour, with a decided pinkness in their flesh. Those feeding on the ordinary water insects are next in brilliancy and flavour, while such as live chiefly upon aquatic vegetables are dull in colour, and of soft consistence. This is further confirmed by the Trout in steves being always finished, or fed off as it is called, on the foresaid Gammari, collected often from a distance. It is only in this way also that we can account for the variation in the appearance and flavour of Trout found in two adjoining bays of the same lake. The individuals, in fact, do not appear to stray to any distance, but seem to be satisfied with whatever food is found within a limited district, and which of course will be in many instances of a peculiar and local kind. It is also true, that the colours of Trout accommodate themselves to the tint of the water, and to the prevailing tone of the bottom, whether of rock or gravel, or of softer substance; and so constantly is this the case, that an experienced and observant angler has little difficulty in accurately predicating the general aspect of the fish of any lake or river. The presence of moss, so frequent in alpine districts, has invariably the effect of deepening the tints, particularly the shades of green and yellow.

In form this fish, when in perfect condition, may be said to be nearly symmetrical; the head only being sometimes rather large in proportion to the body, when considered in relation to what we regard as the beau ideal. The fins are of moderate strength, those of the body assuming a variation of form, from a rounded to a lengthened extremity. The tail is almost always forked; the fins are always coloured, that is, never of the transparent whiteness observable in the migratory species, and their tints are generally of a paler shade than those of the corresponding parts of the body. The anal fin is often bordered on its lower surface with white. The scaling is proportionally less than in the migratory kinds. The toothing is in general strong, and very prominent on both the tongue and vomer.

The average growth of the common Trout, taking the species generally, may be stated at about a pound, and certainly not more than a pound and a half. In almost all rivers, fish weighing beyond this may certainly be found; but they are comparatively uncommon. Individuals from two to six pounds weight are occasionally taken, even in what may be termed a "wild state." In ponds or steams, again, they reach a much greater size, but cannot be said to be in the natural condition of unenclosed fish. The Thames Trout seem to reach most frequently the largest size, being short compared to their length, but of great thickness and well flavoured. Two were lately taken, the one of eleven, the other of fifteen pounds weight. The lakes in the north of England produce Trout of very fine quality, and which are often passed off for Charr. Loch Leven, too (of which the barren isle and now dismantled castle are famous in history as the prison-place of the beautiful Queen Mary), has long been celebrated for its breed of Trout. These, however, have fallen off of late considerably in their general flavour and condition, owing, it is said, to the partial drainage of the loch having destroyed their best feeding ground, by exposing the beds of fresh-water shells, which formed the greater portion of their food. Farther north (as in Sutherlandshire) the immense multitude of lochs produce a corresponding abundance and variety of Trout. Of these, however, only a few are of superior quality; but these few may assuredly vie with the Trout of any country in the world. Another large species, occurring in the British waters, and not yet distinctly known elsewhere, is the—

Salar ferox, Jardine. This species reaches a weight of twenty-eight pounds, and is of very great power compared with its size. The characters which distinguish this fish from S. Ausonii are the great size which it attains in a natural state, the large proportional size of the head, the square extremity of the tail in all the stages of its growth, the relative position of the fins, and the number of rays in the dorsal, which vary from 2–11 to 4–11. The external skin or covering of the scales is also extremely tough; and there is a difference in the form of the scales of the lateral line. In colour the upper parts are generally of a deep purplish brown, shading into purplish gray, and finally, on the lower parts, to greenish or grayish yellow, more or less tinted with orange. The spotting is large and not numerous, and consists of black spots placed in a pale circle, and of large pink spots with a similar light area. These extend over the gill-covers, upper fins, and often over the tail itself. A variety occurs in Loch Loyal, in Sutherland; above, purplish brown; beneath, blackish gray; the whole body spotted over with dark sepia coloured spots, of a smaller size on the lower portions. *Salmo ferox* appears to be entirely confined to the lakes, seldom ascending or descending rivers, or wandering in and out of them, and never migrating to the sea. When spawning, it ascends for a short way up the rivers or streams which run into the lakes, but never, as far as yet known, descends those which run out of them. It inhabits, among the English lakes, Ullswater; but does not there reach a size above ten or eleven pounds. In Ireland, as far as we can yet learn (specimens having not yet reached us on this side of the water), it is found in Loch Neagh and some other large lakes; and in Scotland we have taken it in Loch Awe, Loch Laggan, the upper end of Loch Shin, and Lochs Loyal and Assynt. It is a fish of remarkable ferocity, and as great an enemy to its smaller companions as the Pike. It may be taken by night lines, or by strong trolling tackle, baited with a small Trout, and will return a second and third time to the bait, even after it has been dragged for forty or fifty yards.

The *Salmonidae*, though they take so important a place among the fresh-water fishes of Europe, are still more abundant in the northern Siberian rivers, and in the great lakes and rivers of North America. On the Pacific coast, indeed, of British North America some populous tribes of natives subsist chiefly throughout the year on the Salmon and Trout, which they take at the beginning of the spawning season, and preserve by drying. Descriptions of some of the species are given in the *Fauna Boreali Americana*, and the *Fauna Rossica* of Pallas contains accounts of the numerous interesting Asiatic *Salmonidae*. The common Salmon, we have said above, frequents the Atlantic and Arctic coasts of British North America; but there is a Trout in the great lakes and interior rivers which equals the Salmon in size, and is at least equal to it in flavour and excellence as an article of diet. This is the *Salar namaycush* (Pennant), which is very commonly taken of a size varying from twenty to forty pounds, and is reported to grow to sixty and upwards, though fish of that weight are as rare as a Salmon equally heavy. The *Namaycush* is taken in considerable numbers for the American markets at the fisheries established on Lakes Huron and Superior for the capture of another member of the family of still greater excellence, the *Coregonus sapidus* of Agassiz, or the *albus* of the *Fauna Boreali Americana*. This *Coregonus*, the well known "White Fish" of the fur traders, is found in every lake and river from the United States northwards, and it descends even to the mouths of the rivers that fall into the Arctic Sea. In flavour, and all the qualities that a fish can possess as an article of food, it surpasses, we believe, every other, whether fresh-water or marine; and Europeans, previously accustomed to a sufficient variety of diet, have lived almost solely upon it for a year or more without tiring of it. To the native population it is of vital importance, and it is only in the Buffalo prairies that they can subsist without its aid; while to many tribes it forms the chief food. Within a few years fisheries, employing a large fleet of ships, chiefly belonging to the United States, have been established for the capture of this fish on Lakes Huron and Superior. Several other species of *Coregonus*, known locally by the name of "Herring Salmons," exist in the American waters, but they are much inferior in quality, and resemble the European species more nearly as articles of diet. Even they, however, are delicate food, and would be esteemed were they not so much surpassed by the "White Fish." It may be remarked here that M. Agassiz, who is now in a position to investigate the ichthyology of America thoroughly, has already perceived that every lake, basin, and river system in that country possesses peculiar species of fish, though some species are common to several watersheds. He found this to be the case with *Lepidostomus* and *Coregonus*; and if his observations prove the fact in that continent, we may expect to perceive that the same law exists elsewhere, though the European lake and river systems, being comparatively very small, it may not be so apparent with us. M. Valenciennes describes many European *Coregoni*. Of the British species, he says that the *Coregonus pollan* of Thomson (Yarrell, Supp. 24) is very similar to his *C. sicus*, which inhabits Norway, in the vicinity of the North Cape, but that its head is smaller and its jaws more equal. The *Pollan* inhabits Loch Neagh, and Mr. Thomson says that 17,000 were taken there at either three or four draughts of the net in September 1834. It is a fish that is brought in quantities to Belfast market during its season. Of the *Powan* (Yarrell), the *C. Cepedi* of Parnell, he says that he has found the original description of Noël de la Marinière, on which Lacepede founded his *C. clupeoides*, in which the fish is called also "Span" or "Pollock." Noël had gone to Loch Lomond to see what were said to be sea Herrings naturalized in the freshwater lake, and thus the species was introduced into our systems. Pallas had already used the specific name of *Clupeoides* for another *Coregonus*, and the name given by Dr. Parnell will therefore remain as the scientific appellation of the fish. At Loch Lomond *Shelley* is one of its local names. M. Valenciennes thinks that this species has not yet been discovered on the Continent. *C. Pennanti* is the Welsh *Gwyniad* of Yarrell (*Brit. Fish.*, ii., 85); but, according to M. Valenciennes, very different from the *fera*, with which Pennant confounded it, and equally so from the Lavaret of Switzerland. The specific name of *Pennanti* is therefore employed in the *Histoire des Poissons* to distinguish it. The species which inhabits Lochmaben, a piece of water that bathes the ruins of Bruce's Castle, is locally known as the *Vanguis, Vendace, Jurangis*. According to the traditions of the place, it was originally imported thither from the Continent by Queen Mary. Sir William Jardine was the first who correctly described the Lochmaben fish under the name of *C. Willughbii*, but recognizing at the same time its close resemblance to the *S. albus* of Linnaeus. M. Valenciennes, by a comparison of specimens, has decided it to be in fact the *albus* of the *Fauna Suecia*, and has therefore described it under that specific name in the *Histoire des Poissons*. It is the *Blika* of Lake Siljan in Dalecarlia, and the *Venne*, or, when its resemblance to the Herring is referred to, the *Land-sild* of the inhabitants bordering on Lake Mjöre. According to Bloch, it exists in Silesia, Brandenburg, Pomerania, and Mecklenbourg; and M. Martens found an extremely similar *Coregonus*, if not actually the same, at Kamtschatka. Artedi mentions *Sik-loja* and *Strut* as its Swedish names, *Blieta* as its Silesian one, and *Moisk* and *Ropis* as those by which it is known to the Fins. The *Vendace* of Lochmaben, whatever scientific name it may ultimately receive, is one of the most elegant of the *Coregoni*, though of a small size, reaching from four to ten inches in length. The head is of an angular shape, and small compared with the size and depth of the body. The crown of the head is very transparent, and the form of the brain, which is heart-shaped, is seen through the integuments. This peculiarity is one of the first things pointed out to the stranger naturalist who visits Lochmaben to see this species. The eye is large and brilliant; the body rises gracefully to the back fin, and recedes with a gradual curve to the tail; the under line is nearly straight from the gills to the ventral fin. The upper parts are of a delicate greenish- brown, shading gradually into a clear silvery-white; the dorsal fin greenish-brown, the anterior edge much lengthened and pointed; the lower fins all blush-white; the tail much forked. They spawn about the commencement of November. The roe is minute and abundant, and of a bright orange colour. The flesh is white and rich, and highly prized as food; but as it requires almost to be eaten on the spot, it is not useful as a market commodity when transmitted to any considerable distance. The lochs of Lochmaben are the only authentic British habitat for this species.

The Grayling (Thymalus vulgaris) is a local fish in England, being chiefly found in the Test, the Avon, the Dove, the Lug, the Wye, the Irvon, the Teme, and the Clan, in the southern counties; in the Trent, the Dove, and Dee, in the midland districts, and in the Wiske, the Wharfe, the Ure, the Ribble, and the Derwent, in the northern counties. In America the Graylings have not been detected south of the 61st parallel of latitude, but two or more species abound in the clear affluents of the Mackenzie, issuing from granitic and other primitive rocks. One, the Thymalus signifer, is the most beautiful known species; and the Eskimos, seizing on its most characteristic feature, name it "Hectukpouak" or the "fish with the wing-like fin." It affords fine sport to the angler, tugging like a bull-dog when it feels the hook.

Stenodus MacKenziei, the poison inconnu of the canoe-men who accompanied MacKenzie in his voyage down the great river which bears his name, is still so called by the fur-traders who frequent the district. It ascends the MacKenzie from the Arctic Sea as high as Great Slave Lake, a course of 500 miles, but shuns clear water, and has not hitherto been discovered in any other river than the MacKenzie. M. Valenciennes, having seen no specimen, has not introduced it into his great work, but it is nevertheless a very distinct generic form, not liable to be confounded with any other. When obtained soon after its ascent from the Arctic Sea it is agreeable food, but people who feed solely on it tire of it sooner than either of the "Namaycush" or "White Fish;" and after it has been for some time in fresh water its flesh becomes soft and oily. Its weight varies from five to fifteen pounds, but it has been taken of a considerably greater size.

The preceding pages contain as full an account as our limits will permit of the typical Salmonidae with fleshy cheeks, and, on account of their importance to man, and the general interest felt in their history, we have devoted more space to them than we can give to other groups of fishes. M. Valenciennes has separated the Salmonoids which have the cheeks covered by an enlargement of the sub-orbital scale bones so as to cover, in great part or wholly, the muscles which move the mandible. These present a great variety of forms, which he has subdivided into lesser assemblages of genera. The Characini and Scopelini of Müller nearly comprehend this division, but the group is not exactly the same.

Some of the genera belonging to this division, and named in the table, are vegetable eaters, and have long intestines doubled up in the belly; others are fierce devourers of flesh. Some of the most curious, from their habits, live in the great rivers of South America. The Myletes paca of Humboldt is said to be a fish of exquisite flavour, but with its flesh full of ribs. It is an inhabitant of the Amazon and its affluents. The species of Serrasalmus, so voracious and so expert in carrying away a mouthful of flesh, bitten off with their cutting teeth, are dreaded by the natives of the districts in which they abound. Any animal falling into the water is immediately attacked and cut in pieces by swarms of these fish. Known to the Indians by the names of Caribe or Caribito, on account of their thirst for blood, they assail bathers the instant they plunge into the water, and inflict dangerous wounds before the sufferers are able to escape. Their haunt is at the bottoms of the rivers, but a single drop of blood thrown into the water will bring them in thousands to the surface.

A very curious white and translucent fish is the Salanx Reevesii, known to the Europeans at Canton by the name of "Whitebait," and eaten as a delicacy, served in the same way that the fish of the same name is cooked at Blackwall. One group, the Scopolini of authors, is remarkable for the extreme metallic brilliancy of round spots, placed generally in rows along the body, or for other brilliant places about the head and elsewhere; many are nocturnal, coming to the surface at night, and some have luminous eminences on the head visible in the dark. They abound in the Mediterranean and China seas, but they comparatively rarely appear in northern latitudes.

One species only has been detected on the British shores. The Scopelus Pennanti was first noticed by the naturalist whose name it bears, but was mistaken by him for the Atherine. It has been taken at the island of Sheepy, on the coast of Flintshire, at Exmouth, and in the Orkneys. The S. borealis (Nilss.) is a Norwegian fish, different from the British one. Fig. 24 represents a scale of Scopelus resplendens, an Atlantic fish, and Chauliodus Fieldii is represented by fig. 2.

The Saureys are curious from the forms of the teeth; in some species long, slender, and barbed at the points. The dentition of the S. nacerus (Hamilton), S. ophidion (Cuvier), is of this kind, and on that account Lesueur proposed Harpodon as a generic name for it. It is a fish of voracious habits, and at certain seasons its body is brilliantly phosphorescent, like some of the Scopelines. It is rich food, though delicate when newly taken. When salted and dried it gets the singular appellation of "Bombay ducks" in commerce, or of Bummaloti, and is exported in large quantities from Bombay and the Malabar coast to other parts of India. Fig. 41 shows the form of a scale from the lateral line of Saurus undosquamis (Richardson).

The Galaxias, though they want the adipose fin of the Trouts, yet have much the aspect of these familiar fishes, and represent them in the southern hemisphere, where no true Trouts are found. They are inhabitants of fresh water, and are named "Trouts" by the settlers of New Zealand and Australia. As an article of food they are softer and more oily than the northern Salmonoids.

**Family IV.—Salmonidae**, Müll.

Scaly fishes, with an adipose fin. Upper half of the orifice of the mouth formed by the pre-maxillaries and maxillaries; numerous branchiostegals. A large, simple air-bladder, without contractions; supplementary branchiae, and numerous pyloric caeca. They possess most of the characters of a Clupeoid that has not the acute and deeply divided tail. The mouth is often about as small; often all the pharyngeal bones are armed with teeth; they are curved and in one row, and when they exist on the jaws and palatines the tongue also is furnished with teeth. The distribution of the vomerine teeth furnishes M. Valenciennes with generic characters for the subdivision of this most important but difficult family.

(A.)

**Genus I. Salmo**, Valenc. A few teeth at the end of the vomer, but no prolonged row on the medial line. Body fusiform. Head moderately large; throat well armed, often wide; pre-maxillaries short, and rather on the sides of the mouth than across its upper edge; maxillaries articulated to the ends of the pre-maxillaries, and not compound; mandible strong, often with the symphysis rising into a small tubercle, but in some species the tubercle is much developed. Strong conical teeth on the jaws; a small group at the end of the vomer; one row on the palatines, entopterygoids, and on each side of the tongue; some have two rows on the tongue. An adipose fin on the tail. This small scales covering the body. A short intestinal canal; a siphonal stomach; ova, when detached from the ovary, falling into the cavity of the abdomen before they are excluded in spawning. A large air-bladder, simple, with thin coats, and opening anteriorly into the pharynx, almost directly or without the intervention of an air-tube. With the exception of the peculiarities of the vomerine dentition, many of these characters are common also to the two genera which immediately follow. Twenty-five species.

**Genus II. Fario**, Valenc. Salmonids with a single medial line of teeth running down the vomer. Four species.

**Genus III. Salar**, Valenc. Vomer armed with two rows of teeth, without any remarkable group on the chevron of the vomer, as in the preceding two genera. Eight species, besides about twelve doubtful ones hitherto imperfectly described.

**Genus IV. Osmerus**, Cuv. Pre-maxillary teeth small and hooked; vomerine teeth big, conical, and so far forward that they appear to belong to the vomer; none on the anterior edge of the palatines, and one on the internal border of the entopterygoid. No teeth also on the tongue. In other respects the Spritlings resemble the other Salmonoids. They have a small adipose fin; branchiostegals situated under the anterior rays of the dorsal. Gill-openings widely cleft; air-bladder having within silvery walls, and communicating with the upper part of the oesophagus. Four species.

**Genus V. Mallotus**, Cuv. Mouth rather less widely cleft than that of Osmerus, armed with very small, slender, or conical teeth in a single row on the jaws; more numerous on the palatines and vomer; small teeth also on the tongue. Eight branchiostegals. Intestines of the Trouts. One species.

**Genus VI. Anguilla**, Valenc. Salmonoid, with an adipose fin, and the upper half of the orifice of the mouth formed by the very short pre-maxillaries and the maxillaries. Mouth small; no teeth on the jaws; on the chevron of the vomer a curved band of uniform teeth, prolonged on each side by a dental stripe on the palatines; lingual teeth of variable size in different species. Gill-openings wide; branchiostegals six. Stomach moderately large, cecal; numerous short pyloric caeca; ova falling into the abdominal cavity as in the Salmonids. Air-bladder covered by a coat of silvery fibres, which tear off, and is used in the fabrication of artificial pearls. Four species.

**Genus VII. Thymallus**, Cuv. Mouth small; the orifice horizontal, and nearly smooth; teeth small, conical, unicarinal on the jaws, chevron of the vomer, and for part of the palatines. Intestines like those of Salar. Air-bladder large, communicating with the oesophagus by a very small tube. The disposition of the scales under the throat is peculiar in some species. Eight species.

**Genus VIII. Coregonus**, Cuv. Pre-maxillaries crossing the upper part of the mouth, thin, and of variable depth; maxillaries on the sides of the mouth also thin and attached to the ends of the pre-maxillaries, generally of an oval or oblong form. Teeth small or none. Dorsal fin farther forward than the ventrals. Forty species.

Agassiz retains the name of Coregonus for the species which have the mandible shorter than the upper jaw; and gives the name of Argyropelecus to those which have it longer.

**Genus IX. Sternochis**, Rich. Pre-maxillaries crossing the upper part of the mouth, giving a truncated appearance to the snout, each edged by a narrow limbo-lanceolate band of small radially-armed teeth; maxillaries articulated to the palatines, long and broadish, with a posterior, ovate accessory piece as in the Coregoni, and forming the sides of the mouth; toothless; vomerine teeth in a transversely oval disk on the chevron (but not down the medial line), uniting with the crescentic bands of teeth of the same kind on the palatines. These palatine bands have the hollow of the crescent facing the sides of the mouth, and taper to a point posteriorly. On the tongue, the teeth are rather coarser, and cover its surface. Mandible rather shorter than the upper jaw, the part opposed to the pre-maxillaries transverse with a knob at the symphysis, and armed there by a very narrow band of villiform or radially-armed teeth; lines of the bone longitudinal, with rather acute perfectly toothless edges. The whole orifice of the mouth is nearly quadrangular. In general the Sternochis rather resembles a Coregonus than a Salmon, but bears no strong likeness to either. The ventrals are under the anterior part of the dorsal, and the adipose fin corresponds to the posterior half of the anal, which commences with the last third of the fish, caudal included, and does occupy above a ninth of the entire length of the fish. Branchiostegals nine to eleven, often one more in number on the left side. Stomach but slightly cecal, the upward turn which ends in the pylorus being short, with the oesophagus longitudinally folded within. Pyloric caeca numerous, and crowded for an inch below the pylorus, but after the insertion of the gall-duct confined to one side of the intestine tube. Lower part of the gut furnished with silvery concentric rings. Air-bladder communicating with the oesophagus by a wide tube. Only one species known, the Sternochis Macleanii, Richardson (Buck's Voyage down the Great Fish River in 1834 and 1835, p. 521).

(B.)

M. Valenciennes makes a second division of the Salmonoid fishes by grouping together those in which the sub-orbital scale bones are large, and cover almost the whole, or at least a great part, of the interval between the gills and the ascending limb of the operculum. This division includes the Characidæ and Serrasalmus of Müller; but from the former, M. Valenciennes separates his Erythrinidae.

**Family V.—Characinidae.**

Characidæ, J. Müll. Malacocephalognath fishes with abdominal ventrales; adipose fin; scaly bodies; scaleless head; no accessory branchiae; upper half of the orifice of the mouth formed by the pre-maxillaries and maxillaries; villiform pharyngeal teeth above and below; cecal stomach; numerous branchiostegals; air-bladder divided by a transverse strangulation into two, and connected with the acoustic organs by a chain of osicles as in the Cyprinidæ and Siluridæ. Branchiostegals four or five; numerous pancreatic caeca. South American or African fluvial fish.

M. Müller includes Erythrinidæ and Macrodon among his Characidæ, but these fish want the adipose fin of the Salmon family, and are placed by M. Agassiz near the Clupeidæ. M. Müller's genera Catoptryon, Myloplus, Myloplus, Serrasalmus, Pygocentrus, and Pygopristis, and the genera of other families are Anodus (Carmolus Valenci), Hemiodon, Niphaenotes, Xiphophorus, Hydrocynus, Anostomus, Leporinus, Schizodon, Chilodus, Hydrocynus, Cichlasoma, Piaractus, (including Schizodon, Valenci.), Gasteropelecus, Epicypris, Raphiodon, Pacu (Prochilodus, Agass.), Distichodus, Exodon, Salarias, Brycon, Chalcus, Alestes, Tetrapomopterus.

**Analytical Table of the Characinidae** (Dum.)

Teeth, none

Teeth, none on the tongue, present elsewhere in the mouth.

Teeth elsewhere unicarinal.

Pre-maxillary teeth stronger, tricuspid...Gastroplecusc 14.

Pre-maxillary teeth stronger, conical with canines.

Belly rounded...Epiplatys 3.

Belly keeled...Raphiodon, M. 29.

Pre-maxillary teeth not stouter.

Dorsal opposed to the ventrales.

Pre-maxillary teeth wide, entire...Leporinus 2.

Pre-maxillary teeth fissured...Piaractus, part. 8. Pre-maxillary teeth narrow, round (Citharinus, sp.) Chlorodus, M.

Pre-maxillary teeth narrow, conical (Hydrocyon)

Dorsal not opposed to the ventrals.

Dorsal before the anal (Citharinus)

Dorsal above the anal (Platycodon)

Teeth elsewhere pharyngeal.

Dorsal above the ventrals.

Teeth feebly slender; labial ones bi-serial (Pacu)

Teeth firm, serrated, biseriata (Distichodus)

Teeth large; anterior ones conical (Exodon)

Dorsal between the ventrals and anal.

Teeth conical, triseriata above, biseriata below (Salminus)

Teeth flat, pointed, triseriata on the mandible (Chalcrus, sp.)

Teeth flat, pointed, biseriata above (Beycon)

Belly keeled (Chalcrus)

Belly round (Alestes)

Mandibulars uniseriata (Tetragonopterus)

Mandibulars biseriata (Aleste)

Teeth present on the tongue.

Teeth on both jaws.

Palatine teeth, conical, uniseriata; canines (Xiphorhamphus)

Palatine teeth granular, crowded; canines (Hydrolycus)

Palatine teeth none (Xiphostoma)

Teeth on the mandible; none on the upper jaw (Hemiodus)

GENUS I. CERIMATOS, Valenc. Resembling the Graylings (Phoxinus) in the smallness of their mouth, and feeble dentition, often wholly absent on the jaws. Mouth toothless; jaws with trenchant edges, without lips, the superior one notched to receive a symphysial tubercle of the mandible. Ascending branch of the stomach thick and muscular. Pyloric caeca numerous (amounting to eighteen). Branchiostegals four. Species seven.

GENUS II. LEPORINUS, Spix. Body elongated; belly rounded. Mouth small; lips fleasy; teeth few in number on the pre-maxillaries and mandible; the mesial pair above and below longer than the rest and almost horizontal. Pharyngeal teeth in transverse bands; each tooth having a long laterally compressed crown, terminating in a blunt point of unequal length. Branchial aperture small, from the union of the membrane to the scapula. Branchiostegals four. Pyloric caeca from ten to fifteen. These fish are vegetable feeders. Eight species.

GENUS III. EPICHTUS, Mull. Conical teeth on the pre-maxillaries and maxillaries, some of them projecting from the surface of the jaw like the canines of some Labridae (Callionymus, for instance, figure 56). Pyloric caeca, six or seven. Intestines short. Two species, which include Exodon.

GENUS IV. PARODON, Valenc. Teeth planted in the walls of the upper lip, moveable and slightly curved, their crowns small triangular disks with denticulated edges; mandibular teeth on the side lips only, and not opposed to the pre-maxillary ones of the upper jaw. Four branchiostegals. One species, unknown to Muller.

GENUS V. SALMINUS, Agass. Teeth in several rows on the jaws. Body elongated like that of a Trout, and the mouth also similar, except that the tongue and roof of the mouth are smooth as in most Characins. Pre-maxillary teeth conical, in two rows; one row on the maxillaries; mandibular teeth in two rows, and the interior ones remarkable for their small size, their equality, and their oblique insertion into the limbs of the jaw. Five species.

a. M. Valenciennea forms a group of Prochilodus, Citharinus, Hemiodus, and Platycodon, which have the teeth curiously crenated, and no developed keel to the belly, but with an adipose fin, as in the other Salminidae.

GENUS VI. PROCHILODUS, Agass. (Psen, Mull.) Mouth small, protractile, situated at the extremity of the head, and surrounded by very thick lips, supporting under their edges a row of excessively small teeth like hairs, which, when viewed under a lens of considerable power, are seen to have a disk at the extremity, often denticulated or crenated. Farther back towards the middle of the lips there is a second series of similar teeth in a crescent with the hollow towards the interior of the mouth. Body elongated and somewhat compressed, but clumpish like that of a Carp. Four branchiostegals. Ascending branch of the stomach fleasy, but not so much so as in Carcinatus. Pyloric caeca very numerous, so as to deter one from counting them. Thirteen species.

GENUS VII. CITHARINUS, Cuv. (Including Callionymus, Mull.) Body elevated, compressed, rhomboidal; mouth horizontal at the extremity of the head, the upper arch of the orifice almost entirely formed by the pre-maxillaries, the maxillaries lying behind, but covering the corner of the mouth; teeth extremely small, implanted in the lips, and resembling hairs; none within the mouth. Two species, Nile.

GENUS VIII. PLATYCODON, Cuv. Salmonoids, with uniseriata, trenchant, and compressed teeth, denticulated on the cutting edge, implanted in the lip, and very moveable, the row corresponding to the pre-maxillaries and maxillaries. It comprises the Schizodon of Agassiz and Muller. Three species.

GENUS IX. HERMOIDUS, Mull. Small labial teeth, implanted close to one another in a row on the upper lip; the pre-maxillary and maxillary teeth moveable to the touch like the keys of a piano. There are none on the lower lip. Each tooth is compressed, rounded in front, with denticulated crown or disk. Pre-maxillaries very small and concealed beneath the lip. Mouth very small; body elongated; belly rounded. Branchiostegals four to five. Two species.

GENUS X. TETRAGONOPTERUS, Schil. Teeth on the pre-maxillary set; on each maxillary between the bone and the lip fourteen moveable ones in one row; they are somewhat compressed and pointed; a band of card-like teeth on each palatine, and the tongue also covered with teeth; three pockets formed by a membrane attached before the tongue. Branchiostegals four.

GENUS XI. TETRAGONOPTERUS, Artedi. Body elevated, rhomboidal or orbicular, passing in some species into oval or lengthened forms. Mouth small; two rows of teeth in the upper jaw, one in the lower one. Twenty-one species.

GENUS XII. BRYCNUS, Valenc. Separated from Tetragonopterus. Body elongated as in Chalcrus; teeth crenulated and standing close as in Tetragonopterus. The interval between the two rows is greater in the upper jaw, and a distinctive character exists in the presence of a notch on the crown of the teeth, which resemble those of Chalcrus, but may be readily distinguished; dorsal and anal high. Senegal.

GENUS XIII. PLATUCINA, Valenc. Separated from Tetragonopterus and Platycodon, on account of a combination of characters; body elongated like Platycodon, with fixed crenulated teeth as in Tetragonopterus, but differing from those of the latter in that the double row is on the mandible; on the upper jaw there is only one row. One species resembling Epithecus. Maracaibo.

GENUS XIV. GASTEROPELECUS, Paul., Gronn. Pre-maxillary teeth in two rows, triangular; maxillary teeth conical, much pointed, uniseriata; pharyngeal teeth villoform, closely crowded. Body excessively compressed and high in the posterior region. Dorsal far back. Gill-openings large; branchiostegals eight. Scales. Intestine remarkably short; seven pancreatic caeca. Surinam.

GENUS XV. DISTICHODUS, Mull. Teeth on both jaws in a double row; small, close together, with a slightly compressed forked crown. Body elongated and compressed, belly rounded; caudals and adipose fin scalely like the rest of the body, naked only at the border. Stomach long, ascending branch long and very muscular. Pyloric caeca numerous and elongated like small intestines, extending along one side of the duodenum. A vegetable feeder. One species, the sefsech of the Arabs.

GENUS XVI. ALESTE, Mull. Pre-maxillary teeth in two rows, those of the anterior row larger and more obtuse; while in the interior row the crowns are more obtuse; but there are some projecting points among them; no maxillary teeth; mandibular teeth biseriata, the disk channelled, with crenated crowns; behind the symphysial ones, some small conical ones; pharyngeal teeth very small. Ten to fourteen pyloric caeca. Voracious insectivorous fishes. Air-bladder prolonged posteriorly on the right side of the interbranchial spines, whereas in most other fishes when the air-bladder is extended back out of the abdomen it is forked, and sends a horn on each side of these bones. Three species.

GENUS XVII. MYLLETES, Cuv. Pre-maxillary teeth having truncated crowns, and standing in two rows; for the most part there are only two conical teeth in the inner row, hidden behind the symphysial teeth, but in some species there are seven. The teeth are mostly prismatic with rounded ribs, the crowns of the anterior row being slender, cutting, and feebly denticulated; in the second row the posterior edge is more elevated, and the middle somewhat pointed. Body compressed; belly keeled and often strongly denticulated. First interneural of the dorsal lying horizontally, with its spinous point directed forwards. Intestines long; caecal stomach, with a short, thick, pyloric branch. Vegetable feeders. Seventeen species.

GENUS XVIII. TOMENTES, Valenc. A row of pre-maxillary teeth with sloping or chisel-formed cutting crowns like the bu- Genus XXIX. Myloplus, Mull. Pre-maxillaries armed with two rows of teeth; exterior ones compressed and incisiform; the interior ones truncated, like molars, but with the posterior edge elevated and cutting; mandibular teeth in one row, pointed and incisiform on the anterior part of the jaw, but with no conical ones behind them. Body compressed; belly keeled and denticulated; these dermal osseous teeth forming two rows near the anus. Branchial openings large; pharyngeal teeth villiform; dorsal with its pointed interural spine in front, placed over the interval between the ventrals and anal. Three species.

Genus XX. Mylestes, Valenciennes. Dorsal and anal fins as in Myloplus; pre-maxillary teeth five, sharply cutting, standing closely side by side, with their crowns a little dilated, and having a little curve on each side, so that they may be called tricuspid, though the middle lobe forming the cutting edge of the neck of the tooth is narrower; a little behind the two terminal teeth, though in the same row or nearly so, there are three teeth with truncated or sloping cusps, which are rather notched than tricuspid; mandibular teeth twelve on each limb, in a single row, tricuspid, with the middle cusp oval and elongated; no conical teeth forming a second row at the mandibular symphyses. Lips thick, fleshy, and densely papillose. One species.

Genus XXI. Chalcinus, Cuv. (Brycon, Mull.) Pre-maxillary teeth tricuspid, multicuspid; the anterior ones the smallest, and seeming conical from the smallness of their lateral cusps; mandibular teeth bicuspid, the front ones large and multicuspid, the lateral ones and those of the anterior row conical; behind the symphyses there are several teeth, as in Myloplus. Body elongated, compressed; belly rounded like that of a Trout, but covered with large scales like a Carp. A great number of pyloric caeca. Eleven species.

Genus XXII. Chalcinus, Mull. Pre-maxillary teeth small, crenulated, multicuspid, bicuspid; mandibular teeth, bicuspid like those of Chalcinus, multicuspid, and strong anteriorly; two small conical ones behind the symphysial ones, and an interior lateral row of very small conical ones towards the angle of the mouth. Body compressed; edge of the belly trenchant but not serrated. Dorsal far back; anal very long; and pectorals long and pointed. Three species.

The genus Alpinus of Lowe (Zool. Tr., 1839) probably belongs to some of the preceding genera of Chalcini, but the teeth are not described with sufficient minuteness to determine its proper place.

b. M. Valenciennes makes a small group of Serranulinae, Pygocentridae, and Catopridae.

Genus XXIII. Schizodonmus, Lacépède. Teeth triangular and trenchant, in a single row on the pre-maxillaries, palatines, and mandibular; maxillary not entering into the composition of the orifice of the mouth, but lying under the edge of the pre-orbital, and behind the pre-maxillary. Body compressed, for the most part rhomboidal, the first dorsal and anal ray proceeding from the most prominent points of the upper and under profile; belly keeled and serrated with a double series of dermal spines before the anus; first interscalare of the dorsal projections, branchial point anteriorly; two posteriorly; branchial openings pretty large; four branchiostegals; stomach a very large conical sac; from thirteen to twenty-one pyloric caeca. Voracious carnivorous fishes. Ova not dropping into the cavity of the abdomen.

Genus XXIV. Pygocentrus, Mull. No palatine teeth; pre-maxillary and mandibular bones carrying a single row of triangular, trenchant, feebly-crenulated teeth. Maxillary bone as in Serranulinae, almost hidden behind the pre-maxillary. Body compressed; belly trenchant and serrated, the points near the anus being enlarged; branchiostegals four; caecal stomach; caeca varying from ten to fifteen; air-bladder divided into a small globular anterior part and a very large second one, which communicates with the oesophagus by a very short canal. Ova not dropping into the cavity of the abdomen. Four species.

Genus XXV. Pygocentrus, Mull. Separated from Pygocentridae by the edentate and smooth roof of the mouth, but the jaw teeth are crenulated, and strongly denticulated. Two species.

Genus XXVI. Catoptrion, Mull. and Troech. Salmonoids, with a serrated belly, having two rows of conical pre-maxillary teeth, and one row of trenchant triangular mandibular ones. One species.

Genus XXVII. Hydrocyon, Cuv. Salmonoids, with large and strong teeth implanted in a single row on both jaws; these teeth are conical, slightly compressed, and have cutting edges; roof of the mouth smooth. Body elongated; sides flattened in the middle; belly rounded like the back; intestine very short, with a considerable number of pancreatic caeca (thirty-five to forty). Branchiostegals four. One species.

Genus XXVIII. Cynopotamus, Valenciennes. Differ from Hydrocyon in having two rows of pointed pre-maxillary teeth, those of the exterior row very short; interior row containing four large canines; maxillary on the side of the orifice of the mouth like that of a trout, edged by a row of very small conical teeth; mandible armed at the end by eight canines; and a second interior row is composed of very small teeth; palate destitute of both teeth and palatines, excepting the angular five.

Genus XXIX. Cynodon, Spix. Salmonoids, with granular teeth on the palate; pre-maxillaries, maxillaries, and mandible armed by a single row of pointed conical teeth, among which there are enormous canines, the largest being near the symphyses, those of the mandible entering corresponding holes in the palate. Body much compressed at the pectorals; belly frequently compressed; anal very long and scaly. Pectorals pointed and laid along the body, descending to a right angle with the longitudinal axis when they act. Stomach remarkably large. Carnivorous. Three species. Cynodon semicirratus, Val., is the genus Hydrocyon of Muller.

Genus XXX. Xiphophryncus, Agassiz. Differs from Cynodon in having a single row of pointed teeth on the palatines, as well as on the jaws. Carnivorous fish. Twelve pancreatic caeca or thereabouts. Five species.

Genus XXXI. Agoniates, Mull. Intermediate between Hydrocyon, which is remarkable for long canines, and Tetraopsorus, which has two rows of pre-maxillary teeth, some of them tricuspid. This dentition distinguishes Agoniates from Cynopomus. One species.

Genus XXXII. Xiphostoma, Spix. Snout conical and elongated by the extension of the pre-maxillaries, palatines, nasal and prefrontal, and the dorsal aspect of the skull wholly covered by a granular engraved casque. The elongated pre-maxillaries and the snout are furnished with numerous minute teeth, set closely side by side in a single row, their points curved like a small fish-hook; palatines wrinkled longitudinally, with oblong granulations. Body slender, elongated, and round. Dorsal very far back beyond the ventrals. Pancreatic caeca very considerable in number. Five species.

Genus XXXIII. Salanx, Cuv. (Leporinus, Gray.) Body slenderly fusiform, the thin end of the spindle being the anterior one; jaws equal, the cleft of the mouth horizontal, slightly arched in the middle; maxillary curving over the corner of the mouth, and sending a slip in front of the end of the pre-maxillary, forming a considerable part of the border of the orifice; pre-maxillaries armed with a simple series of small teeth, with four tall, subulate, recurved canines projecting on each bone; the space near to the symphyses have only a row of small ones; maxillaries armed with a serrated row of short teeth; mandibular teeth on the sides of the bone smaller and more numerous than those of the upper jaw; tip of the mandible toothless, but close to it there are three strong teeth, whose points when the jaws are close pass through a rhomboidal membranous space near the point of the snout; palatine bones set with a row of fine teeth, but there are no teeth on the vomer, which does not project. Ventrais about the middle of the fish; dorsal in the middle of the posterior half; the anal still nearer the caudal fin, and the adipose fin corresponding to the posterior part of the anal. One species.

Genus XXXIV. Hydropanchus, Reinhardt. Teeth on the pre-maxillaries, elongated maxillaries, and mandible, uniseriate, canines and conical ones intermixed; the anterior mandibular teeth received into pits in the palate; palatine teeth minute, granular; pharyngeal teeth villiform. Body elongated, compressed; belly keeled. Scales small. Gill-openings extremely large; five branchiostegals; internal rakers of the branchial arches having the form of small ossaceous tubercles, studded with the finest spines; ventral fins none; dorsal fin over the anal, which is exceedingly long, and has a scaly base. (An. 1850.)

Genus XXXV. Genostoma, Rafinesque. Pre-maxillaries short, not covering the edge of the maxillaries, completing the upper half of the mouth; as in the Cynodon or Salmonoides; teeth large, conical, and sharply pointed, widely set on the jaws, with very few ones in the intervals; palatines and entoglossalords covered with minute raduliform teeth, and there are rough spots on the tongue; pharynx very narrow, the superior pharyngeal teeth resembling the teeth of a narrow; in two groups, the anterior group composed of three teeth larger and longer than the rest; fourteen branchiostegals, suborbital very delicate; dorsal placed far back; free recurved spines on the sides of the tail. Ovarian sacs shut. One species.

Genus XXXVI. Chaetodons, Bleek. (Astronotus, Richardson. Phoxodon, Lowe, Ann. Nat. Hist., x, p. 522.) Mouth formed nearly as in Goniostoma, but the dentition differs; the teeth are slender pointed, compressed, and curved, adhering to the bone; mandibular ones being the largest; maxillaries well arranged in a peculiar manner on the edge of the bone, inclining backwards; palatine teeth shorter; tongue armed on the sides with teeth; pharyngeal teeth barrow-like. Branchiostegals fifteen to seventeen; pectoral fins attached low down; gill-openings large; dorsal far back, anal still more posterior, its last rays opposite to the thin adipose fin. *Astroscopus major*, R., fig. 2, p. 132.

Mr. Ayres, in the Journal of the Boston N.H. Society for 1849, describes a fish which seems nearly allied to Chasmodes, but if the symphysial mandibular barbel and branchiostegals have not been overlooked, they may not be the same. The generic characters given of it are as follows:

**Genus XXXVII. Malacostomus**, Ayres. Scales small; mouth very deeply cleft; its upper border chiefly formed by the maxillaries; pre-maxillaries short; pre-maxillary and maxillary teeth small, sharp pointed; mandibular teeth very long, somewhat curved, smaller ones behind them; no teeth on the palatines, vomer, or gill-arches; a double row on the tongue; and a tuft on each pharyngeal; small fins; dorsal far back over the anal; gill-cover membranous without ossification, and no branchiostegals perceptible.

All the bones unusually soft. One species, *M. nigra*, found in the North Atlantic. Could the bones have been softened by spoiled spirits?

**Genus XXXVIII. Aplochiton**, Jenyns. Characterized by a peculiar fold or longitudinal pouch in the integuments of the belly; wholly without scales; uniserial small teeth on both jaws; two rows on the tongue and vomer; none on the palatines; branchiostegals three. Elongated form of a Grayling, but thicker. Magellan's Straits.

The last six genera are scarcely members of this family.

---

**Family VI.—Scopelidae.**

*Scopelos*, Müll.; *Sauridus*, Valenc. Scaly or scaleless fishes with an adipose fin, whose mouth is bounded above from corner to corner by the pre-maxillaries, the maxillary lying behind; accessory gills; swim-bladder wanting; in most *Gnathosaurus*, Cav.; *Saurus*, Cuv.; *Sauridus*, Cav.; *Malacostomus*, Cocco.; *Ichthyosaurus*, Bonap.; *Chirocentrus*, Bonap.; *Odontostomus*, Cocco.; *Paralepis*, Risso.; *Saila*, Raf. not Cav.; *Sternoptyx*, Herm.; *Argyropelcus*, Cocco.

They are separated from the Salmonidae by the structure of the mouth, and by the ova being discharged by a proper canal, and not falling into the general cavity of the abdomen. The maxillaries in some genera approach the corner of the mouth, and form a portion of its orifice, and in *Argyropelcus* they are formed of three pieces, one of which is dentiferous. This genus and *Sternoptyx* belong, by the structure of the mouth, to the Characidiae.

**Genus I. Argyropelcus**, Herm. Body greatly compressed, high, with an irregular polygonal outline; tail narrow at its commencement, and generally very thin near the caudal fin; mouth nearly vertical, formed above by the pre-maxillaries and maxillaries, the latter in some species occupying but a small part of its orifice, in others nearly the whole upper half; maxillary composed of three pieces, one of them dentiferous; curved, unequal teeth on the jaws; smaller ones on the palatines; branchiostegals nine; the scapular chain of bones largely developed; thin nasal osseous crest; four pancreatic ceca. Four species.

**Genus II. Sternoptyx**, Herm. Body high, compressed, with long ribs seen through the silvery integument; mouth cleft almost vertically; maxillary with very short pre-maxillaries, and on the sides by the maxillaries, as in *Salmo* or *Salar*; pluriserial teeth on the jaws, the shorter ones placed in an exterior row, and the larger ones more interiorly; palatines armed with two or three longer curved teeth anteriorly; vomer edentate; branchial arches and inferior pharyngeals rough with small teeth, but the extremity of the tongue smooth. The dentition of the jaws is like that of *Saurus*, and the palatine teeth resemble those of *Chasmodes*. Gill-openings wide; branchiostegals five, of different forms; coracoid bones forming a keel with an anterior point under the throat; public bones also having a sharp point; a triangular osseous crest before the dorsal, with one large projecting spinous point. Adipose fin pretty long. One species.

**Genus III. Odontostomus**, Cocco. Upper half of the mouth formed entirely by the pre-maxillaries which carry the teeth, the maxillary lying posteriorly and being toothless; mandible, palatines, and chevron of the vomer armed with moveable teeth, which rise by their elasticity when pressed down; no teeth on the tongue; eye large, with an adipose fold. One species.

**Genus IV. Scopelos**, Cuv. (*Myctophus*, *Muraenellus*, *Lampanyctus*, Bonap.). Upper half of the mouth bordered by the pre-maxillary, the toothless maxillary supporting it behind; teeth of the jaws small, and differing little in size; on the palatines the teeth are minutely raduliform; no teeth on vomer, in which the genus differs from Odontostomus. Twenty species.

**Genus V. Saurus**, Cuv. Elongated body, wide mouth, long rounded pre-maxillaries, armed in a point; pre-teeth styloid maxillary being hidden under the palatines. Teeth numerous, conical, somewhat curved, and often with a haste or barbed point, forming barrow-like bands on the jaws, the palatines, tongue, and pharyngeals; the small teeth being in the exterior ranks, and the larger ones internally. First rays of the ventrals shorter than the posterior ones, as in *Platycephalus* and *Callionymus*, and also in the united ventrals of *Gobius*. Branchiostegals sixteen; sub-operculum large, also frequently the inter-operculum. Cesal stomach large, with a short pyloric branch; pancreatic ceca few. Ovaries in a sheath. No air-bladder. Seven species.

**Genus VI. Sarididae**, Valenciennes. Differ from *Saurus* in having an internal band of acetic teeth surrounded by minute ones, as well as the band of longer palatine teeth which *Saurus* possesses; internal ventral rays not so much prolonged as in that genus. Two species.

**Genus VII. Parionella**, Valenc. Resembling a Trout. Dorsal standing over the space between the ventrals and anal; an adipose fin above the end of the anal; caudal small. Upper half of the moderate-sized orifice of the mouth formed by the pre-maxillaries, the very small toothless maxillary lying behind. Teeth simple and conical on the pre-maxillaries, palatines, and mandibular, also along each side of the tongue. One species.

**Genus VIII. Chirocentrus**, Cocco. Ventral cavity dilated posteriorly, with supplementary pieces, but bordered in front by the pre-maxillaries, which form the upper border of the mouth. Teeth small, crowded, nearly of equal size, forming a narrow band on both jaws, on the palatines, and on the chevron of the vomer; two dental plates of very fine teeth on the entopterygoids, and the pharyngeals above and below bristle with pretty strong heckle-formed teeth. Large gill-openings. Bones of the head cavernous, with spinous points on the hinder part. Thick jointed inferior rays on the pectoral, as in some *Stereolepis*, with which in other respects the genus presents many analogies. It has also somewhat of the external aspect of a Gobius, but is allied more closely to *Saurus* by dentition, and the presence of an adipose fin. Two species.

**Genus IX. Paralepis**, Risso. (*Saila*, Rafines). Malacoptygian abdominal fish, with an adipose fin, slender fusiform bodies, elongated jaws, and the upper half of the orifice of the mouth formed by the pre-maxillaries, which pass before the maxillaries. Dorsal and ventrals opposite to each other and very far back; adipose fin radiated, but the rays not articulated like true rays. Teeth trenchant, much like those of *Sphyraena*. In the Hist. des Pois, the first dorsal was considered to be spinous, but Reinhardt has shown that its rays are articulated, and Muller assigns it a position in the Atlantic and Australian seas.

**Genus X. Alepisaurus**, Lowe. Body elongated, tapering, mouth large, with a wide-edged posteriorly above and below. Jaws elongated, with a wide mouth, which is bordered above from corner to corner by the pre-maxillaries, armed with small subulate teeth; lanceolate teeth on the palatines and sides of the mandible, with long subulate ones on the fore part of the latter bone. The dentition has much resemblance to that of *Sphyraena* or *Leptodactylus*, and the bones have great similarity in structure to those of the *Scomberidae*. No teeth on the vomer. A long anterior dorsal extending backwards from the nape; posterior one adipose; ventrals abdominal. Neither air-bladder nor pyloric ceca. Lowe. Three species in the Atlantic and Australian seas.

**Family VII.—Galaxidae.**

Shape of a Trout, but with no adipose fin, and the dorsal far back. No scales. Moderate-sized, uniserial pointed teeth on the pre-maxillaries and mandible, sometimes three canines at the curve of the latter; stronger curved styloid teeth in one row on the palatines and each side of the tongue; pre-maxillaries not reaching the corner of the mouth, but the maxillary is excluded from the edge of the orifice by the thick lip. Inhabit fresh waters in Australia, Van Diemen's Land, New Zealand, the Falklands, and Patagonia, where they represent the Trouts.

**Genus I. Galaxias**, Cuv. Seven species.

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**HYODONTS.**

This small family group was instituted by M. Valenciennes to comprehend three genera, which have the greatly compressed sides of the Herrings, but not the serratures on the lower edge of the belly exhibited by all the typical members of that family; the presence of pancreatic ceca separates them from *Chirocentrus* with which they would Family VIII.—Hyodontidae.

Hydontes, Valenciennes places in this group Osteoglossum, Ichthyostomus, and Hyodon, which have compressed bodies, and a keeled belly, without denticulations, but with pancreatic caecum, the presence of which, he says, alone separates them from Chirocentrus, though the suborbital scale bones are more developed than in the latter. Their intestinal canal resembles that of the Mormyrids.

Genus I. Osteoglossum, Pereira. Body and head compressed like the blade of a sabre; head bony above, and the cheeks protected by the suborbital and opercular pieces; mouth much cleft; small conical teeth on the premaxillaries and slender maxillaries, which are fitted together partially concealed by the preorbital; lower jaw armed like the upper one with two fleshy barbels under the symphyses; minute crowded teeth on the vomer, the palatines, entopterygoids, presphenoid, lingual bone, and body of the hyoid bone. Gill-openings very large, overlaid by the addorsal branchial border of the gill-cover; branchiostegal ten. Anal long, but separated from the small caudal; ventrals ending in a filamentous point. Belly treeshaped, but without denticulations; stomach rounded, without any excausal projection; two pancreatic caeca; air-bladder large, simple, without either partitions or horn-like prolongations, but communicating with the upper part of the oesophagus by a tube having an excessively small mouth. Two species, one in the Amazon, the other in Borneo.

Genus II. Ichthyostomus, Spix. An Osteoglossum, with the anal and caudal united.

Genus III. Hyodon, Leach, Rafinesque. Body oval, greatly compressed, thickest above the lateral line; back acute, belly more so; profile suboval. Dorsal short, over the long anal. Eyes large, preorbital scale bones covering the whole of the cheek; mouth wide, premaxillaries and maxillaries forming equal portions of its upper border. These bones have uniserial conical teeth, largest towards the symphyses; the mandible has two rows with their points inclined backwards, and the interval between the rows covered with minute teeth; the vomer is similarly armed, but the dental surface widens gradually as it approaches the gullet; the palatines are armed by a single row of conical teeth, with a small oval plate of very minute ones within; the tongue is broad, the tongue strongly armed by a marginal row of hooked teeth bigger than the others, and the rest of the surface covered with minute card-like teeth, having their points reflexed. Stomach spherical; one pancreatic caecum; air-bladder large, communicating with the oesophagus. Fresh-water North American fish.

Clupeosocidae.

This family was indicated by Müller in his treatise on the Natural Families of Fish, and was considered by him to be distinct from the true Herrings by having no pseudobranchiae, which the Clupeoids all possess. On subsequently examining some examples of the genus Megalops, he found the pseudobranchiae present, though evanescently small; and he also discovered that Gnathobolus, a genus closely related to Notopterus, has pectinated pseudobranchiae. He therefore ceased to consider the Clupeosocidae as a separate family, and referring them all to the Clupeidae, enumerates as members of that family, Clupea, Pristigaster, Alepocephalus, Gnathobolus, Notopterus, Engraulis, Thryssa, Megalops, Elops, Lutodectes, Hyodon, Etrurinus, Chirocentrus, Stomias, Chaetodus, Heterotis, Arapaima and Osteoglossum. Neither Amia nor Chaetodus have pseudobranchiae. M. Valenciennes has treated of the genera here enumerated as intermediate between the Clupeidae and Esocidae, and considers several of them to be types of distinct families, some of which have been named by him. After abstracting these, the remainder are here placed under the head of Clupeosocidae, as a convenient term indicating their position between the natural families of the Herrings and Pikes. When their anatomy has been more perfectly investigated, they will be distributed by ichthyologists to their proper places in the system. One part of the structure of a fish is much attended to by Müller in his searches after the natural affinities of the various genera he examines, viz., the investments of the ovaries, or the organs which hold the roe or eggs. In the Salmon tribe the eggs are not contained in a separate sac, but drop off from the ovary as they come to maturity, into the general cavity of the abdomen, and are expelled from thence; in the Galaxidae and in various groups that have been separated from the Salmonidae, the ovaries are inclosed in a sac, which has a canal of its own, through which the eggs pass in the process of spawning. A too rigid adherence to a single character often separates fish that are connected by many natural affinities; and some of the Clupeosocidae would associate well with the Scopelidae did they possess an adipose dorsal; the absence or presence of teeth on the palate has also been occasionally made of too much importance by systematists.

The genus Notopterus is peculiarly interesting to systematic naturalists on account of the combination of characters of very different orders of fish which it presents. With the compressed body of a Clupeoid, it has the denticulations of the preorbitalis, subperculum, and mandible, and the cranial crests observed in several families of Acanthopteri, together with a Gobioid union of the ventrals, in which also it agrees with Gonorynchus; the dentition, especially the existence of spheroidal teeth, allies it to Butirinus, while the armature of the tongue brings it near to the Hyodontidae or to Mormyrids. The eggs are not shut up in a sac, but fall freely into the abdominal cavity as in the Salmonidae.

The genus Arapaima, so named by Müller, and since called Vastus by Valenciennes, was termed Sudis by Cuvier; but Rafinesque having previously used the word Sudis to denote a fish of a totally different kind, the name has been necessarily dropped as an appellation of this genus. The species are of much interest not only from the peculiarities of structure which they exhibit, and their encasement in strong, bony, compound scales, but from the great size which they attain, exceeding that of almost all other fresh-water fishes, and also from the excellence of their flesh as an article of food. Sir R. Schomburgk mentions, that in the Rio Negro some are taken which measure fifteen feet in length, and weigh four hundredweight. They are harpooned, or taken with a baited hook, and are the objects of considerable fisheries. They fetch a high price, and are excellent when fresh, especially the belly part which is very fat. When salted they are exported in large quantities to Para, and are there preferred to the salted fish from the banks of Newfoundland.

Butirinus and Heterotis are also interesting, but more from peculiarities of their structure than from their utility to man, though, as articles of food they rank among the more highly prized fishes.

Family IX.—Clupeosocidae, Mull.

No adipose fin; no accessory gills; premaxillaries bounding the orifice of the mouth in the middle above, and the maxillaries the sides. Some have a movable swim-bladder; pyloric caeca in a few, in others absent. Distinguished from the Clupeidae by the absence of accessory gills. They include the following genera: Somias, Chirocentrus, Notopterus, Osteoglossum, Heterotis, and Sudis, Cuv. (or Arapaima, Mull.)

These genera were either associated with Esoc by M. Valenciennes, or considered as types of peculiar families; and at a later period Muller ceased to consider these fish as forming a proper family, but we have placed them together until appropriate positions are found for them. Genus I. Stomias, Cuv. Elongated scaly fish, having somewhat the form of Scomberosus, but with a short high head and a barbel depending between the limbs of the mandible. Dorsal and anal opposite near the caudal; ventrals in the posterior quarter of the fish before the vertical fins. Scales fine, forming hexagonal divisions in the skin, not imbricated. Mouth deep far back in the head, which is near the end of the body; short smooth upper border of the mouth formed by the premaxillaries and maxillaries; mandible prolonged beyond the maxillary; strong conical-subulate curved teeth on the premaxillaries and mandible, with very small teeth on the part of the maxillary, which passes beyond the premaxillary; small teeth exist between the tall ones; the tongue is toothed in the same manner, and the branchial rakers are in the form of long, hooked teeth. Branchiostegals seventeen; pretty large gill-openings. Allimentary canal a long straight tube, without a stomachic dilatation; no pancreatic ceca; ovaries, two long sacs; a long slender air-bladder. One Mediterranean species.

The wanting of adipose fin appears to be the only character that separates this fish from Clupeoides, and other Raphidion.

Genus II. Microlepidotus, Valenciennes. General form of Stomias, but less elongated, with a small head and a very small mouth, wholly anterior to the proportionally enormous eye. The anal behind the dorsal, and neither of them so far back as in Stomias. Upper half of the orifice of the mouth formed by the small premaxillaries and maxillaries, both without teeth; a few vomerine teeth, none on the palatines, nor on the tongues or pharyngeals, but the branchial rakers are long and pointed. Branchiostegals four. Intestine and air-bladder as in Stomias; pseudobranchium created. One Mediterranean species. The specimen in the Paris Museum is the same with Risso's, but the imperfect descriptions of the latter giving it an adipose fin, led M. Valenciennes to believe them to be different species. The genus, says M. Valenciennes, approaches Esox, and even Cyprinus, by the absence of pancreatic ceca; but they depart from these families to place themselves near the Clupeoids by the junction of the premaxillaries and maxillaries. It is a family of only one species, forming the

Genus III. Chirocentrus, Cuv. Body compressed, elongated; belly trenchant, not denticulated. Dorsal far back on the tail, opposite to the anal; pectorals pointed with a long styloid bone in the axilla covered with scales; ventrals excessively small. Pharyngeal teeth strong and curved; two mesial premaxillary teeth horizontal; upper jaw formed of small premaxillaries soldered to coniferous maxillaries, which have two supplementary pieces as in Clupeus, one of the hinder pair being placed anteriorly, the other succeeding beyond the corner of the mouth; teeth very fine and short on the palatines, two pterygoid bones, the tongue, the branchial arches, and the pharyngeals. Stomach cecal; intestine short, with the interior mucous coat forming a long spiral valve; no pancreatic ceca; swim-bladder long, slender, with interior imperfect transverse partitions, and an air-tube going to the stomach. Branchiostegals eight.

Genus IV. Notopterus, Valenciennes. Body greatly compressed, very thin towards the tail. Snout obtuse, with little projection, the nasal bone scarcely passing the turbinial; two small premaxillaries placed transversely at the extremity of the nasal, and suspending the free maxillaries, the latter a short distance from each other in the Clupeidae; limits of the maxillaries having a deep cleft; dorsal cavity with two trenchant edges carrying teeth; jaws armed with minute raduliform teeth, also the palatines; a small spot on the end of the vomer, an oval surface on the presphenoid; and very long crooked ones on the edges of the tongue. The foremost two suborbital scale bones are serrated on their edges, and also the edges of a large hollow on the inferior limb of the preoperculum, which hides entirely the smooth interoperculum; operculum large, and suborbicular morayceus or in the Serranidae. Large muciferous cavities in the cranium, on which there are three longitudinal ridges, namely, a mesial interorbital one and two lateral ones; on each side, the suborbicular is also prominent and pierced for the passage of nerves. Dorsal very small; anal very long and united to a small caudal; ventrals united to one another, but scarcely perceptible from their minuteness. A genital papilla behind the anus. Belly very much compressed, and edged by a double series of denticulations. Scales small, covering the body, the gill-covers, and part of the cheeks; lateral line straight. Branchiostegals seven, erroneously stated in the "Reyes Animalia" to be only one. Stomach compressed, globular, with the cardia and pylorus in front, one over the other. Ova not shut up in an ovicase, but dropping into the abdominal cavity. Air-bladder multibulbar, having its thin membrane enveloped in an exterior fibrous sac, communicating with the stomach by a short tube. Nine species.

Notoparce is considered by M. Valenciennes to be the type of a Classification peculiar family.

Genus V. Arapaima, Mull. (Sudla, Cuv.; now Rafin.; Fustero, Valenciennes). Body more or less rounded, covered by a mosaic work of osseous scales, which extend over the vertical fins, dorsal and anal, short, and fin bases. Head formed of deeply sculptured bones, with numerous cells, clothed in a thick skin; large cheek bones; mouth pretty large, bordered above by the premaxillaries and maxillaries, both carrying teeth, and below by the mandible, toothed in the same way; small raduliform teeth cover the palatines, the pterygoids, the vomer, the presphenoid, the lingual bone, and all the body of the os hyoides; and there is a plate of teeth on the internal surface of the mandible; the presphenoidal and palatine teeth vary with the species. Air-bladder said to be cellular like the lungs of a fowl; two valves at the arterial orifice of the ventricles, and no muscular bulb. About six species in the rivers of South America.

Genus VI. Haemulon, Ehren. A large elongated head, clothed in mucous skin, and hard mucous scales on the body, give this genus a resemblance to Sudla, but the vertical fins are not scaly. The teeth stand in a single row on the jaws, they are recurved with a rounded point; no teeth on the palatines, vomer, or presphenoid, but there are groups of straight conical teeth on the pterygoids and dilated part of the hyoid bone. Two long, thick, pancreatic ceca. A cellular air-bladder enters into rings formed by the parapophyses of the caudal vertebrae, as in the Esoxoidi. Two species, Africa.

Genus VII. Butirrhines, Cuv. (Albula, Gronov.) Has the general aspect of some of the Indian Cyprinoides. Body regularly fusiform, with a conical head, and pointed snout, passing the end of the mandible a little. Dorsal in the middle of the length, its hinder third opposite the ventrals, the anal halfway between the latter and the largely-forked caudal. Head naked. Body covered with large, hard, firm scales; furrows on the cranium perceptible through the skin. Fine card-like teeth on the jaws, palatines, front of the vomer, and pharyngeals; and what is characteristic of the genus are small, cap-shaped, hemispherical patches of teeth, covering a part of the presphenoid, and another on each pterygoid. The convex tongue fits into the canal formed by these three bones, and its surface is also covered with granular teeth. Intestines like those of the Clupeidae. Pancreatic ceca large, cecal; pancreatic ceca two, external and internal cells in the anterior part of the rectum; pancreatic sac opening on each side of the anus. A long air-bladder, having its thin membrane enveloped in an exterior fibrous sac, communicates with the stomach by a short tube. Nine species.

The Butirrhines, says M. Valenciennes, are undoubtedly allied to the Clupeoids by their large air-bladder and numerous pancreatic ceca, and the want of teeth on the maxillary, but they are kept apart from that family by the absence of a keeled denticulated belly.

ERYTHRINID.E.

A small family established by M. Valenciennes of several genera whose true place in the system has been much canvassed. Erythrinus is stated by the ichthyologist just named, to present in its skeleton a resemblance to the Salmonidae in the adjustment of the bones of the face, to the Cyprinidae in the size of the lateral occipital foramina, to the Clupeidae in the parieto-occipital foramina, and in the form of the basi-occipital, which differs totally from that of the Cyprinoids in wanting that vaulted dilatation to which the median pharyngeal plate is attached in that family; but again it possesses Cyprinoid characters in the union of the first vertebrae and in the existence of the Weberian ossicles, connecting the air-bladder with the auditory organs, though not exactly in the same way as in the Cyprinidae.

Family X.—ERYTHRINID.E:

Erythrinoides, Valenciennes. Body moderately thick; back and belly rounded; head large; snout obtuse; upper arch of the mouth formed of the small premaxillaries, with the maxillaries articulated to their extremities, both crowded with small conical teeth, as is also the vomer; villiform teeth on the palatines and pterygoids, and form an arched plate on the roof of the mouth, separated from its fellow on the other side by a smooth vomerine line; pharyngeal teeth also villiform. Entire cheek covered by bony suborbital scales, followed by two temporal plates which are characteristic of the family. Stomach conical, siphonal; pancreatic ceca numerous; The existence of a bone between the limbs of the lower mandible is one of the characters of this family, and the want of it in Butrinus (left among the somewhat heterogeneous Clupeoidea) is the reason why M. Valenciennes did not place that genus with his Elopidae. Amia is another genus in which this sublingual bone is present, but Müller has adduced various arguments founded on its structure for considering it to be one of the few living Ganoids, and we shall accordingly mention it under that order along with the Lepidostidae which are more unequivocal Ganoids.

The figure No. 75 represents the Elops saurus, or Silver-fish of Garden, a fish which has been introduced into our systematic works under four different specific names and three generic ones. It is the only representative of the genus Elops yet discovered, and is one of the few fishes which are common to the warmer parts of both the Atlantic and Pacific Oceans. It has been captured at New Orleans, Surinam, and on the coast of the Brazils; also on the opposite African coast at Senegal. In the Red Sea also, at the Isle of France, in the Indian Ocean, and, lastly, on the North Australian coasts and in the seas of Polynesia, westward to Japan and China.

There is a likeness between the genera Lutodaira and Elops, but the great number of branchiostegals which the latter possesses at once distinguishes them.

**Family XI.—ELOPIDAE.**

*Elopus*, Valenc. Separated by M. Valenciennes on account of the presence of a sublingual bone from the Batrachoides, to which they are nearly allied. This bone exists in Amia, but that genus has another kind of dentition. These fish are remarkable among their allies for the number of their branchiostegals, and the median bone under the branchiostegal membrane, between the limbs of the mandible, is also an unusual part of their structure. The mouth is, like that of the Clupeidae, bordered above by small premaxillaries, and the free maxillaries on the side. Teeth so fine on the premaxillaries, maxillaries, vomer, palatines, entopterygoids, vomer, presphenoid, and tongue, that they are scarcely to be felt as asperities. Body long and rounded; no denticulations whatever on the belly. Dorsal medial, with no prolongation of the last ray. An enlarged and indurated scale on the dorsal and ventral edge of the base of the deeply-forked caudal; long scaly appendages in the axilla of the ventrals and pectorals. Head naked; a diaphanous, waxy-looking, adipose eye-membrane. Stomach conical, with an ascending fleshy branch; numerous pyloric ceca; a large air-bladder communicating with the digestive canal, and forked anteriorly, but not entering the cranium.

**Genus I. Elopus**, Linn. Character of the family as above. Two species.

**Genus II. Megalops**, Cuvier. Body elongated, of moderate height and elegant form. Mouth bordered above by the small premaxillaries, and by the large, moveable, compound maxillaries on the sides, with the edges of both rough with minute teeth; there are teeth also on the mandible, the palatines, the pterygoids, the front of the vomer, the presphenoid, the lingual and hyoid bones, and on the pharyngeals. Wide gill-openings; branchiostegals numerous (twenty-two to twenty-five). A sublingual bone between the limbs of the mandible. An adipose eye-lid to the pretty large eye. Small dorsal, with the tip of the last ray filamentous and long. A large conical stomach; numerous slender, filiform, pancreatic ceca; air-bladder large, forked anteriorly, with an air-pipe from it opening into the pharynx. Three species.

**Mormyridae.**

A small family of fishes which abound in the rivers of both sides of Africa, the Nile, Senegal, and Congo. They are timid fish, of nocturnal habits, that frequent rocky basins in the rivers, and would be seldom taken but for the high price they command, which renders the fishermen very assiduous. They are caught with lines to which many hooks baited with worms are affixed, and one fisherman rarely succeeds in taking more than two or three in the course of the night. Their flesh has an excellent flavour, and is greatly esteemed by the epicures of Egypt. These fish seem to have been objects of as great attention to the ancient Egyptians as they are to the present inhabitants of that country. In the Egyptian museum of Paris there is a small bronze representation of one of the sharp-nosed... Mormyri surmounted by the mythic horned circle emblematic of the divinity Athor; and mummified Mormyri are not rare. Sir J. Gardner Wilkinson says that the name of these fish in modern Egypt is Mizdeh; and in page 250 of the second volume of the second series of Ancient Egypt, he gives two very recognisable representations of a Mormyrus taken from bronzes, one of them crowned by the emblem in question. A third figure is copied from a representation of the fish in the temple of the Great Oasis, where it is coupled with the name of the goddess, and shows, Sir Gardner thinks, that the fable of the metamorphosis of Venus into a fish was of Egyptian origin. The ancient Egyptians appear to have made the Mormyrus an object of veneration, but to have abstained from eating it, according to Plutarch, because it was one of three different kinds which devoured a part of the body of Osiris, and which Isis therefore was unable to recover when she collected the rest of the scattered members of her husband. The Mormyrus longipinnis of Rüppell, or M. caschire of Hasselquist and Valenciennes, has been ascertained to possess electric organs, which probably exist in other species also, and may be one reason for the veneration of the whole genus by the ancient Egyptians. The long-finned species represented by one of the bronzes figured by Sir Gardner Wilkinson is either this M. caschire or the M. oxyrhinchus which has also a long dorsal. Müller found the premaxillaries of the Mormyrii to be united so as to form a single bone.

**Family XII.—MORMYRIDE, Mull.**

*Mormyri*, Cuv. Longish compressed bodies, with a tail slender at its origin, but swelling out at the attachment of the caudal. Head encased in a thick, naked skin, which envelops the gill-covers and branchiostegals, or leaves only a perpendicular slit for a gill-opening. Branchiostegals six. Mouth small, and bounded above medially by a single bone formed of the coalescent premaxillaries as in *Diodon*; laterally the maxillaries enter into the composition of the orifice. Dentition various. The post-frontal or temporal apparatus is simpler than in other fish, therein resembling the Siluridae. The cranium has a peculiar canal closed by the skin, leading to the interior hollow of the skull, and the acoustic labyrinth. Accessory gills absent; stomach globular; intestine long and slender; two pyloric ceca; swim-bladder simple.

**Genus I. Mormyrus**, Mull. A row of slender teeth, curved at the tips on the premaxillaries and mandible, and in the young a stripe of radially-formed teeth on the hinder parts of the vomer. *M. cyprinoides* has a double air-bladder.

**Genus II. Mormyrops**, Mull. Conical teeth on the jaws in place of curved tipped ones. *M. anguilloides*, Valenciennes.

M. Valenciennes does not adopt these genera of M. Müller, as he says that conical and slender teeth exist on the jaws of the same species. He describes twenty species, in two groups, characterized by the length of the dorsal fin. Since the publication of the Histoire des Poissons, Peters has discovered six new ones on the Mozambique coast. Most of the species described by M. Valenciennes have two minute lateral cusps to the teeth, separated by a notch as in *Crenidens*.

**Cyprinodonts.**

The typical forms of this family are small fishes, formerly considered to be Cyprinoids, but, as their name denotes, differing from the true Carps in possessing teeth, and, moreover, in having protractile jaws; they want also the kind of pharyngeal grinding apparatus which is peculiar to the Carps. Species exist both in the Old and New Worlds; and some inhabit indifferently fresh, brackish, or salt water. We have seen specimens procured in a brine spring and salt marsh on the shores of the Dead Sea, on the supposed site of Sodom, probably from one of the slime pits of Siddim of which the valley was full in Abraham's time. In one member of this family, the Guapucha (*Pecilia bogotensis*), which inhabits the little river of Bogota on the plateau of Santa Fe, 8810 feet above the sea level, Humboldt found a double air-bladder; and, on examining the contained air, ascertained that 93 parts in 100 were azote, the rest being carbonic acid and oxygen. The Orestias are found at a still greater altitude, being inhabitants of Lake Titicaca and other elevated sheets of water on the Cordilleras of laosopteri, Peru and Bolivia, between the 14th and 19th degrees of latitude, and from 13,000 to 14,000 feet above the sea. The flesh of these fishes is a great delicacy; and they are sought for during the winter season, when they can be transported without spoiling.

*Anebleys* is a genus which excites the attention of the dullest of observers by a conformation of the eyes which no other vertebrate animal possesses, in the cornea being divided into two somewhat unequal elliptical parts by a bridge of the conjunctiva, giving to each eye the appearance of being double. This very peculiar structure has most likely a connection with the habit the fish has of swimming with the eyes partly out of the water. *Panclax* and *Vandellia* were considered by M. Valenciennes to have affinities with *Pacilia*, but owing to their possessing teeth on the palate he places them after *Esor*. Neither has *Dipteryx* been enumerated among the Cyprinodonts by Müller, but no other more convenient place for these three genera occurs than just before the Esocide.

**Family XIII.—CYPRINODONTID.E, Agass.**

*Cyprinodontes*, Agass. This is a very precise family, with prominent characters. Its members resemble the Cyprinids in habit, but they do not possess the large pharyngeal teeth, nor the bony process of the basi-occipital. Upper and under pharyngeal teeth card-like; maxillary as in the Cyprinids, and the premaxillaries forming alone the upper half of the mouth, but they are armed with teeth; jaws protractile. Swim-bladder simple, and furnished with a chain of acoustic ossicles. No suprarenal gills. Stomach siphonal; no pectoral ceca. Scales viviparous.

**Genus I. Pecilia**, Valenciennes depressed, horizontal and prolonged; the upper border of the mouth formed solely by the premaxillaries; convergent and curved teeth on both jaws in an exterior row, with a stripe of villiform teeth behind; roof of the mouth edentate, soft; many rows of hooked teeth on the pharyngeals. Five branchiostegals. A single, simple air-bladder. Long, simple intestines; viviparous. Eight species.

**Genus II. Mollienesia**, Lesueur. Having the dentition, branchiostegals, and intestines of *Pecilia*, they differ in the position of the anus, advanced to between the ventrals, which are rather far back. A large and long dorsal and expanded caudal. One species, Lake Poecilichthys.

**Genus III. Xiphophorus**, Heck. Teeth bristly, short, surrounded by a row of smaller ones. Ventrales as in Mollienesia; anal in the male close to the ventrales, the front rays thickened, connected together by a long plate, whose extremity is used as a prehectoral organ; the posterior rays very short. Three Mexican species.

**Genus IV. Cyprinodon**, Lacépède. Teeth rather less depressed than in *Pecilia*, the teeth in a single close row, compressed and tricuspid. Branchiostegals five. Intestines and air-bladder of *Pecilia*. Small fishes resembling a Minnow. Eight species.

**Genus V. Fundulus**, Lacépède. Characterized by the presence of fine card-like teeth on arched premaxillaries, the upper half of the orifice of the mouth being semicircular. Head flat beneath; and the jaws not depressed as in *Pecilia*. Branchiostegals five. Eight species.

**Genus VI. Hydromyza**, Lacépède. Teeth of *Fundulus*. Six branchiostegals. Four species.

**Genus VII. Grundulus**, Valenciennes. Body compressed, oval; the flat upper jaw shorter than the mandible; numerous teeth on the jaws. Dorsal far back, opposite to the anal. Branchiostegals five. Air-bladder double, the posterior one much the largest. One species, seen only by Baron Humboldt.

**Genus VIII. Orestias**, Valenciennes. Thickly fusiform, apodail, scaly fishes. Dorsal and anal opposite to each other, behind the middle of the body, on the commencement of the tail. Mouth rather small at the extremity of a muzzle which bulges beneath by the projection of the mandible; teeth fine and hooked; pharyngeal teeth card-like. Five branchiostegals. Scales of the fore part of the fish hard horny beaded, with occasional intervals of naked skin; posteriorly they are ordinary cycloid scales like those of a Carp. Lower part of the belly destitute of scales, shining and metallic in lustre. Nine species, Andes.

M. Gervais has instituted a genus which he names Tellis, for an Genus IX. Anableps, Bloch. Elongated scaly fishes, with a flattened, rounded back, and depressed head. The maxillaries carry no teeth, and do not enter into the composition of the border of the mouth, which is formed above by the premaxillaries alone. On these there are teeth, the outer row being moveable like those of Perissodus, and the inner minute, in a crowded band; roof of the mouth smooth, edentate; tongue a very small tubercle; pharyngeal teeth two plates, above and below, conical pointed, villiform, crowded; lips thick; eyes prominent under a scaly arch, having the cornea and iris divided by a longitudinal band, so as to give them the appearance of being double. Branchiostegals five. In the male the external opening of the organs of generation, common also to the urinary bladder, is carried along the front of the anal beyond the tip of its first ray, in a tapering appendage, with the orifice at the extremity. The female is viviparous, but seldom produces more than seven or eight young at a time. Air-bladder pretty large, with a pneumatic duct in the foetal state, which is obliterated as the fish attains maturity. Four or five species.

Genus X. Diplopterus, Gray. (Diplocephalus, Bleeker.) Is placed by its affinities between Cyprinodon and Esox; the existence of vomerine teeth brings it near Panchax, which it resembles in the position of the ventrals under the pectorals. A single anamnathoid dorsal opposite the anal. Upper half of the mouth composed of the very protractile premaxillaries, which have moreover a half circle of teeth on their ascending pedicels, and uniserial teeth on their labial lips; mandibular teeth pluriserial in front; vomer rough, with minute teeth; four complete branchial arches; no pseudobranchium; inferior pharyngeals with a barbula armed with conical teeth. Gill-openings large, coming forward under the eye. Branchiostegals five. Nostrils two in the preorbital space. Scales Cosmoid on the body, Cycloid on the head. Stomach caecal, intestine short; no pancreatic coeca.

Genus XI. Panchax, Hamilt. Buch. Thickly fusiform scaly fishes, highest in the middle, and tapering rather more towards the head than posteriorly. Dorsal far back over the posterior part of the larger anal; abdominal ventrals before the middle of the fish. Upper arch of the mouth formed by the premaxillaries, behind whose descending limbs the maxillary lies and does not touch the edge of the orifice, which is garnished all round by a narrow band of teeth as fine as hairs. Teeth on the palatines; branchiostegals five.

Genus XII. Vandellia, Valenciennes. Body elongated, rounded, slenderer anteriorly; snout depressed, prominent; mouth small, situated on the ventral aspect; lips thick, with a fleshy barbel at the corners of the mouth on each side; teeth on the vomer; none, or little visible teeth on other parts of the mouth. Ventrals small, on the posterior third of the body; dorsal standing over the interval between the ventrals and anal. One species, India.

ESOCIDÆ.

By the abstraction of groups formerly included in the Pike family, only a single genus remains to represent it, and of this there is only one European species, viz., Esox lucius, Linn. (the common Pike). During the earliest stage of its life it is of a greenish hue, but in the second year it becomes gray with pale spots, the latter ultimately acquiring a yellowish colour. Its markings, however, are very variable, and instances have occurred of its being perfectly white. It is one of the largest of fresh-water fishes, and indeed, if the accounts which some writers give are not exaggerated, it occasionally attains a size not tion—Ma- was in 1537. Leland mentions that a Pike of great size was taken in Ramesmere, Huntingdonshire, in the reign of Edgar. Pikes are proverbially voracious. There seems, indeed, to be no bounds to their gluttony; for they devour indiscriminately whatever edible substances they fall in with, and almost every animal they are able to subdue. "It is," says M. de Lacépéde, "the Shark of the fresh waters; it reigns there a devastating tyrant, like the shark in the midst of the ocean; insatiable in its appetites, it ravages with fearful rapidity the streams, the lakes, and the fish-ponds that it inhabits. Blindly ferocious, it does not spare its species, and even devours its own young; gluttonous without choice, it tears and swallows, with a sort of fury, the remains even of putrefied carcasses. This bloodthirsty animal is also one of those to which nature has accorded the longest duration of years; for ages it terrifies, agitates, pursues, destroys, and consumes the feeble inhabitants of the waters which it infests; and as if, in spite of its insatiable cruelty, it was meant that it should receive every advantage, it has not only been gifted with strength, with size, with numerous weapons, but it has also been adorned with elegance of form, symmetry of proportions, and variety and richness of colour." A singular instance of its voracity is related by Johnston, who asserts that he saw one killed which contained in its belly another Pike of large size, and the latter, on being opened, was found to have swallowed a water-rat! Its flesh is well flavoured and easy of digestion, and consequently much sought after as an article of food, especially for convalescents, and others of weakly habit. It is most tender and nutritive in young individuals, but full-grown Pikes are occasionally found in which the flesh on the back and near the vertebral column acquires a greenish colour, which is held in high repute, and often purchased at a great price. Sibbald, writing in the reign of Charles the Second, says that the heart of the Pike is a remedy against febrile paroxysms, that the gall is of much use in affections of the eyes, that the dried jaws reduced to powder are a remedy in pleurisy, gravel, and stone in the bladder, and that the ashes of the fish are used to dress old wounds. These and the rest of his statements on medical subjects have the formal approbation of the President and Censor of the Royal College of Physicians of Edinburgh.

Even the names of the Pike is a subject not without its interest. It is the Lucio or Linzzo of the Italians, an appellation evidently descended from the Latin lucius. Ausonius, in using this term, says that it was a despised fish on the Moselle, very contrary to the estimation in which it was held in England ten centuries later—

"Lucius, obscuras ulva cenoque lacunas Obsidet. Hic nullos mensarum lectus ad usum, Fervet famosis olido nidore populis."

In Sweden it is named Gadda, and in Denmark Giedde, Gedde, Gede, or Gei, names differing little from the appellation of the fish in the lowlands of Scotland, "Ged," and showing, with many other instances of Scandinavian words relating to maritime affairs and fisheries, the origin of the population that displaced the Celtic races from the country lying to the south of the Firth of Forth, and on the east coast of Scotland still farther north. M. Valenciennes has printed a long list of the names which the fish bears among the Slavonic and Tartar peoples, none of which seem to have any relation to those by which it is known on the western coast of Europe. The Scandinavian name had probably its origin in the sharpness of the teeth of the Pike, and the consequent danger of injury to those who attempted to handle it; for we find a similar word, Gede or Geede, used to designate a goat in Danish (also lowland Scottish "Gait"), and Gedehams, to signify a hornet. The English names Pike and Pickerel are evidently sprung from the Saxon Pik (sharp-pointed), and the French Canadians term the Lucioperca of that country the Piccarel, which it well merits, as its teeth are no less formidable than those of the Esox lucius.

**Family XIV.—ESOCIDÆ, Mail**

Scaly fishes without an adipose fin, and possessing covered glandular accessory branchiae. Orifice of the mouth formed above in the middle by the premaxillaries, and on the sides by the maxillaries. A simple swim-bladder. Diffuse vascular ramifications exist on the inner surface of the skin, which are peculiar to this family. Stomach siphonal; no pancreatic oes. Type of form the common Pike; inhabitants of fresh waters only, in the northern hemisphere.

**Genus I. ESOX, aus.**

**Gonorhynchus.**

The members of this small family are more interesting from the peculiarities of structure that they exhibit, and which are briefly denoted in the generic characters, than by their importance in an economical point of view. The Chanos, however, has been named Milk Fish, from its delicacy as an article of food.

![Fig. 77. Chanos or Latodactylus salmonoides.]

A scale of this fish has been represented on a preceding page (fig. 40), and the following woodcuts give the portrait of Gonorhynchus Greyi, a fish of Western Australia, and of one of its scales.

![Fig. 78. Gonorhynchus Greyi.]

On the Alepocephalide, we have no remarks to make.

**Family XV.—Gonorhynchide.**

Gonorhynques, Valenc. This small family was constituted by M. Valenciennes for the reception of two genera which want oral teeth, and thus have some affinity with the Cyprinidae.

**Genus I. Chanos, Lacép. (Latodactylus, Van Hass., Rupp.)** The Chanos have an affinity to the Alepocephalide, distinctly belonging to that family, and are separated from the characteristic Herrings by a small belly, not rounded and not carinate, nor denticulated. They resemble the Buteridæ and Gonorhynche in their fatty eyelids, toothless jaws, and scaly appendages in the axilla of the pectorals and ventrals; they have, moreover, a lanceolate scaly fillet above and below the lateral line on each side, extending longitudinally over the caudal, dividing the long acute lobes of the forked caudal from a small central portion. Chanos is further character- Family XVI.—Alepocephalidae, Valenciennes.

This family consists of a single species, of which M. Valenciennes says "the genus Alepocephalus is separated from all others, and forms the type of a peculiar family." The upper jaw is that of the Pike (Esox), with an alimentary canal like that of the Clupeoids, and a spiral valve in the rectum like Aria, but with many pancreatic ceca and no air-bladder, whereas Aria and Chirostomus have remarkable air-bladders and no pancreatic ceca. No desmatacations on the belly like those of the Clupeoids. Body compressed, rounded beneath; long scaleless head. Short premaxillaries bearing teeth, forming the upper half of the mouth; toothless maxillaries lying behind them; palatine and mandibular teeth small. Siphonal stomach with numerous pancreatic ceca; spiral valve in the rectum.

One species.

Genus I. Alepocephalus, Risso.

Cyprinoids.

This large family is a very natural one, but the great conformity of structure exhibited by its very numerous species is a source of difficulty to ichthyologists who have attempted to divide it into genera, and other subordinate groups. It is wholly a fresh-water family, and among the least carnivorous in the class of fishes.

Cyprinus carpio, the common Carp. This well-known fish is of an olive-green, yellowish beneath, having the anal and dorsal spines strong and denticulated, and the barbels short; the pharyngeal teeth are flat and striated on the crown. It is a native of the central countries of Europe; but, owing to its value as an article of food, it was early distributed by human agency over the whole of that Continent. The case with which it can be transported from one place to another, and its speedy growth and propagation in ponds and artificial reservoirs, afforded great facilities for its rapid dispersion. The year 1614 is assigned as the date of its first introduction into England; but it was naturalized in Germany and Sweden nearly half a century before that period. It delights in tranquil waters, preferring such as have a muddy bottom, and the surface partially shaded with plants. Its food consists of the larvae of aquatic insects, minute Testacea, worms, and the tender blades and shoots of plants. The leaves of lettuce, and other succulent plants of a similar kind, are said to be particularly agreeable to them, and to fatten them sooner than any other food. Although the Carp eats with great voracity when its supply of aliment is abundant—to such a degree, indeed, as sometimes to produce indigestion, which occasionally proves fatal—it can subsist for an astonishing length of time without nourishment. In the winter, when the Carps assemble in great numbers, and bury themselves among the mud and the roots of plants, they often remain for many months without eating. They can also be preserved alive for a considerable length of time out of the water, especially if care be taken to moisten them occasionally as they become dry. Advantage is often taken of this circumstance to transport them alive, by packing them among damp herbage, or wet linen; and the operation is said to be unattended with any risk to the animal, especially if the precaution be taken to put a piece of bread in its mouth steeped in brandy! In a similar way, the Dutch preserve them by suspending them from the roof of a damp apartment in a bag-net filled with moss, which is continually kept moist, and they are fed with vegetables and bread steeped in milk—a mode of treatment by which they are not only kept alive, but actually thrive and fatten.

The fecundity of these fishes is very great, and their numbers consequently would soon become excessive, but for the many enemies by which their spawn is destroyed. No fewer than 700,000 eggs have been found in the ovaria of a single Carp, and that too by no means an individual of the largest size. Their growth is very rapid, more so perhaps than that of any other fresh-water fish, and the size which they sometimes attain is very considerable. In certain lakes in Germany and Prussia, individuals are occasionally taken weighing thirty or forty pounds; and Pallas relates that they occur in the Volga five feet in length, and even of greater weight than the examples just alluded to. The largest of which we have any account is that mentioned by Bloch, taken near Frankfort-on-the-Oder which weighed seventy pounds, and measured nearly nine feet in length. M. Valenciennes commends the small figure of the Carp in Mr Yarrell's British Fishes, as being the very best representation of the fish that he had seen.

Cyprinus auratus (Gold Fish). This beautiful species, the most brilliantly adorned of all our fresh-water fishes, and scarcely surpassed even by the more richly ornamented inhabitants of the ocean, is well known to be a native of China, although it is now domesticated, so to speak, in almost every country, both of the old and new world. Like the Carp, it has the dorsal and anal spines denticulated. When young it is of a blackish colour, and it gradually acquires the fine golden red by which it is characterized; but some examples are of a silvery hue, and others are variegated with three different shades of colour. Like most other animals that have been long estranged from their natural habits, and subjected to artificial influences, this species presents a great many varieties, extending even to some important parts of structure. Individuals occur without a dorsal, others with a very large one, others with the caudal greatly enlarged, and divided into three or four lobes; and in some instances the eyes are enormously dilated. The Golden Carp is said to have been originally confined to a lake near the mountain Tsienking, in the province of The-kiang, in China, about N. Lat. 30°. It was first brought to England in 1691, but was very scarce till 1728, when a considerable number were imported, and they soon became generally known. They do not flourish in rivers and open ponds, not, however, because such places are uncongenial to them, but because they are exposed to many enemies, against which they have no means of de- The Tench (Tinca vulgaris) is of a deep yellowish brown, sometimes, however, assuming a fine golden colour. Its usual length is from 12 to 14 inches; but instances are on record of its having reached 3 feet. It inhabits stagnant waters with a muddy bottom; and in the winter conceals itself among the mud, and seems to undergo a kind of torpidity. In May and June it deposits its ova among aquatic plants; these are very minute, of a green colour, and so numerous that 297,000 have been reckoned in one female. The Tench is very extensively distributed, appearing to occur throughout Europe and Northern Asia.

"Quis non et virides vulgi solatia Tinco norit."

Genus XXXIV. Heterobranchus, Geoff. Dorsal shorter than in Clarion, the rest of the back being occupied by an adipose fin; caudal rounded. Head broad and flat; supracranial process of the helmet rounded. Short, fine, crowded villiform or bristle-like teeth on the jaws and arc of the vomer; a complex subpharyngeal apparatus. Six barbels. Three species.

Genus XXXV. Saccombranchus, Valenci. Helmet like Clarion and Heterobranchus. Villiform teeth on the jaws, and two arches of dermal plates on the vomer; a complex subpharyngeal apparatus. Small dorsal far forward; long anal. Seven branchiostegals; the branchial reservoir different in form from that of Clarion or Heterobranchus. Eight barbels. One species.

Genus XXXVI. Plopusus, Lacp. An elongated body, ending in a compressed pointed tail. No hard helmet, the smooth rounded depressed skull being covered with soft skin. Lips fleshy; strong conical teeth on the jaws; pavement-like teeth on the vomer; eight barbels. A short, higher, anterior dorsal, and a long, low, posterior one, uniting with the long anal at the point of the tail, without a distinct caudal. Small branchiostegal, toothed and pointed dorsal and anal spines; a fleshy flap-shaped opercle in a funnel behind the anus; of yellowish hue, existing in addition to the genital aperture at the external opening of the seminal ducts. Nine species.

Genus XXXVII. Aspidura, Linna. Differs from other fish in the gill-covers being fixed and without motion, there being merely vestiges of the three opercular pieces, soldered to the preoperculum. Mouth peculiar; the premaxillaries being articulated longitudinally under the snout, and carrying teeth on their posterior edge only; and the maxillaries ending in barbels, articulated to the nasal anterior to the premaxillaries. Head flat, anteriorly. Body naked, wide at the pectoral region, tapering into a long slender tail, truncate beneath, and terminated by a distinct small caudal. Dorsal small and high; strong, flat, serrated anterior spines; four to six adipose fins; each fin having spines on the ventral surface at certain times. Branchiostegals five. Six species, all American. McClelland describes five Indian fish belonging to a genus named Glyptosternon, which does not seem to differ from Aspidura in the characters that he assigns to it.

Genus XXXVIII. Chaca, Valenci. Head broad and much depressed, as wide before as behind, thus being quadrangular; tail tapering and much compressed at the end. Two dorsals and two anal; posterior ones uniting to form a caudal at the extremity of the tail, or it may be said, caudal running forward on the dorsal aspect to above the front of the head; about half as far on the ventral aspect, so that which part of view them they will be seen anal and only dorsal near the head, and joined by a long conical first ray. Seventeen pectoral spines. The chin ciliated by eight filaments. Air-bladder very large, composed of two lobes separated by the spinal column.

Genus XXXIX. Sisor, Hamilton. Bich. A Hypostomus without lateral pieces of mail; its skin being soft; remarkable for the size of its premaxillary barbels, and the prolongation of the upper caudal ray into a filament as long as the rest of the fish. Body slender, long; the chevron in front of the dorsal three-lobed. Mouth edentate, with fourteen barbels in all. Large gill-openings; four branchiostegals. One species, which attains the length of seven feet.

Genus XL. Malapterurus, Lacp. No anterior dorsal; an adipose fin behind the caudal; very broad beyond the middle of the fish; and an anal occupying about half the distance between them and the rounded caudal; no pectoral spine. Body shaped somewhat like that of a Cobitis or Galaxias, the tail being thickish, but the head is conical and ends bluntly. Lips fleshy, with six barbels; fine villiform teeth on each jaw; none on the vomer. A short oblique gill-opening; branchiostegals seven. Stomach small, siphonal; air-bladder fusiform, pointed posteriorly with two globular lobes in front, in advance of the osicles of Weber. Its outer coat is thick and spongy. A double electrical organ.

Genus XLI. Allia, Gray. A long, greatly compressed, moderately deep fish, with a small head and rounded snout like a Cobitis. Back naked, except near the tail, where there is a small adipose fin; a very broad, oval anal, and forked caudal. Eight barbels. Teeth on the jaws and roof of the mouth minute.

Genus XLII. Trichomycterus, Valenci. Allied to Malapterurus by general form, the depression of the head, thinning of the snout, and construction of the cranium, but distinguished by a dorsal placed in the middle of the back, the absence of an adipose fin, and the want of an air-bladder. Branchiostegals eight. Aspect considerably like that of Cobitis. Six barbels, one at each anterior nostril, and a pair at the corner of the mouth on each side. Tall thickish. Fine curved teeth in a band on the jaws; palate smoothed. Three species.

Genus XLIII. Eremophilus, Humb. Closely resembling Trichomycterus in general aspect, but apodous; connected like that Classificatory genus to the Siluroids by the absence of subopercula; and to Cobitis tention—Malapterur. by the want of ventrals. Jaws armed by a band of long villiform or lacertiform, bristle-like teeth. Branchiostegals eight; no scales. Siphonal stomach and long intestine; no air-bladder.

GONIODONTS.

This family has grown out of the genus Loricaria of Linnaeus, which, as characterized by him, consisted of fishes whose bodies were mailed in hard angular plates or scales, distinguished from Doras and Collichthys by the mouth opening under the snout. Müller considers them to be a separate group of the Siluroid family, and as such they are described by Valenciennes, in the Histoire des Poissons. Lacepede divided the Linnaean Loricaria into two groups, reserving that appellation for the species that have no adipose fin, and giving the name of Hypostoma to those that have a kind of adipose fin but one that is preceded by a hard bony ray. Agassiz, when characterizing and naming the family, adopted Lacepede's generic divisions, and added two others, Rhinelepis and Acanthicus. The premaxillary and mandibular teeth of the Goniodonts are composed of albuminous tissue, like the teeth of the Characoids, and have the same elasticity.

In the Loricaria the top of the skull is prolonged backwards by the extension of the supraoccipital, which forms a kind of first scale, that reaches to the two plates developed from the points of the intercrauls of the first compound vertebra,—the second of the plates being the chevron, on which the spine of the dorsal stands and moves. The mastoids and suprascapulae enlarge the sides of the skull, and form the wide osseous vault, which affords the necessary space and breadth for containing the anterior portion of the abdominal viscera. The diaphyses of the great compound vertebra are plates curved like a sabre, and are supported below by the centra, and above by a styloid process resting on the vertical occipital crest. The scapular arch is very strong and shuts up the fore-part of the abdomen by a bony septum, while the coracoids, in form of the letter V, give the firmness necessary to sustain the dermal shields and spines. The coalescent radius and ulna bent horizontally support the pectoral plates. There are only eight abdominal vertebrae, with ribs as fine as bristles, and sixteen caudal ones.

Family XIX.—GONIODONTIDÆ.

Confederates, Agass.; Loricariini, alcurum. Related to the Siluridæ, but differing from them in possessing pseudobranchia, and in their intestines. Head and body mailed in hard, angular plates; orifice of the mouth on the ventral aspect; absence of the smooth bones; the premaxillaries and maxillaries; long, slender, flexible, with ends ending in hooks on the premaxillaries and mandible, which are separated at the symphyses; a broad, circular, cuticular fold surrounds the mouth. Gill-cover mostly immovable; the styloid epibranchial absent as in the Siluridæ, and represented by a process of the coracoid. The heart lodges in a bony capsule formed by the coracoid. No caecal enlargement of the stomach; intestine long, frequently bent; no pancreatic caeca. Swim-bladder wanting, in which they differ from the Siluridæ. There is much phosphate of lime in the scales.

Genus I. Loricaria, Luct. Body depressed, broader than high. Tail very much compressed. Teeth in both jaws. A single dorsal and no adipose fin.

Genus II. Hemionus, Knor. Body very much depressed. Teeth on the mandible only. Premaxillaries rudimentary; toothless.

Genus III. Acestra, Knor. Body elongated, nearly cylindrical. Teeth in both jaws, furnished with a transverse radical process. Dorsal and anal fins opposite.

Genus IV. Rhinelepis, Agass. Osseous plates resembling scales, imbricated, rough like a file. A short thick body. Lower lip often dilated into a membranous velum, and fringed with filaments. Three branchiostegals. Hooked teeth surrounding the orifice of the mouth in rows; the front ones notched at the point. A single dorsal. Three species. ORDER III.—PHARYNGOGNATHI, Müll.

This order is founded on the character, common to all its members, of the lower pharyngeals being united to form one bone. In external aspect there is no similarity between the families of Scomberesocidae and Labridae, which belong to it.

SUB-ORDER I.—MALACOPTERYGII.

Fins without spines.

SCOMBERESOCIDÆ.

Of this group of Pharyngognaths we may obtain a correct notion from the Garfish or Greenbones of our coasts, named also by the fishermen Mackerel Guides, because they annually come into shallow waters at the time of the Mackerel fisheries. This fish belongs to the genus Belone which contains many species, and among others B. caudimaculata and B. canalicula, which inhabit the fresh waters of the peninsula of Hindostan, and afford an instance, in addition to many others, that generic assemblages are independent of habitat, as to the species being marine, lacustrine, or fluvial. The British seas furnish an example of the genus Scomberesox, also, in the Saury Pike or Skipper. The latter name is given in consequence of the habit these fishes have of leaping out of the water, which is also practised by the Belones. Some species of this genus have an air-bladder, while others want it; a remarkable peculiarity in fishes so similar in aspect, but which also occurs among the Mackerels.

The Exocoeti or Flying Fishes have ever been an object of great interest to navigators. The monotonous and quiet voyage of a ship running before the trade-winds is enlivened by the flights of large bands of these creatures rising before the bows of the vessel, and like a flight of larks or sandpipers glittering in the sun, and often by a simultaneous impulse, changing the direct line for one nearly at right angles, before settling in their native element again. The muscular force by which this progress through the air is effected has engaged the attention of Humboldt. This illustrious and accurate observer states that the Flying Fish move by myriads constantly in a right line, and in a direction opposite to that of the waves. He doubts whether this flight be generally assumed as a means of escape from voracious fishes, and with reason. As we have noticed above, their near allies the Belones and Scomberesoces have the habit at certain times of leaping frequently from the water, and we have observed the same thing to occur in the spawning season among the shoals of Mallotii, which often land themselves in numbers on the dry beach. There seems to be something in the constitution of these fishes which impels them to this movement, and the Exocoeti are organized to carry it to the fullest extent by the size of their pectoral fins and the power of the muscles which move them. There are some who assert that the flight of the Exocoeti is a mere leap, resembling the ricochet of a stone skimming along the surface of the water, but the pectorals are certainly impelled against the air in the course of the flight. The bands frequently undulate in their height above the water before subsiding into it again; and, as mentioned above, it is not rare to see them change their direction, though this is not done till just before the termination of their aerial course. Their flight is rapid, greatly exceeding that of a ship going 10 miles an hour, and we are not inclined to limit it to a distance of 500 feet. It is not easy to form a correct judgment of distance under such circumstances; but having often watched their flights when in a frigate 120 feet long, it appeared to us to exceed the length of the ship many times, and its altitude was such that in the night they frequently fell on board. Many shoals, consisting entirely of small ones, from 2 to 3 inches long, showed a smaller power of sustaining themselves in the air, and more frequently glanced against the summit of the coming wave, but the larger kinds rose vigorously into the air.

FAMILY I.—SCOMBERESOCIDÆ, Müll.

Maxillaries coalescent with or adherent to the elongated premaxillaries at the corner of the mouth, under the nasal, and covered on part or wholly by the preorbital scale bone.

GENUS I. BELONE, Cuv. Upper border of the jaw formed by the premaxillaries, which, together with the mandible, are elongated into a long bill; teeth on these bones forming a narrow stripe, the interior row consisting of taller conical ones; roof of the mouth smooth (except in the species which frequents the Channel); two small patches of teeth in the upper pharyngeals, more pointed than those on the lower pharyngeals, which are short, conical, inclining to the pavement form. Gill-openings large; branchiostegals, twelve. A hard helmet, formed of the cranial bones, is variously sculptured and furrowed. Body elongated. Scales very thin, like those of Scomber, and not easily perceptible, excepting a row of headed ones on each side. Dorsal and anal opposite each other, and far back. No pyloric ceca; large air-bladder. Twenty-six species.

GENUS II. SCOMBERESOX, Lacép.; Sauries, Rafin. Jaws constructed nearly as in Belone, but the mandible is always the longest, and the maxillary, instead of being confluent with the premaxillary, is merely in apposition; the teeth are extremely small, and uniserial on the jaws; none on the roof of the mouth or tongue. Shape of the body much as in Belone. Dorsal and anal far back, opposite to one another, and followed by detached filaments of variable number, according to the species. A very keen sense of smell, which becomes obsolete near the anal, and does not reach the caudal. No pancreatic ceca; the air-bladder present in some species, wanting in others, as in the species of Scomber. Five species.

GENUS III. HEMIRAMPHUS, Cuv. The distinctive character of this genus is expressed by the name, and consists in the edentate, pointed projection of the mandibular symphysis, producing a kind of half bill. The upper jaw is formed by the premaxillaries soldered together, and the maxillaries joined to them at the angle of the mouth wide and form a spur which is concealed by the preorbital. A narrow band of small granular teeth exists in both jaws. In other respects these fishes resemble Belone, except that the gill-opening is enlarged, and is included within the opercular ceca. The air-bladder runs the whole length of the abdomen, between the spine and a tense arch of the peritoneum; and in the species (three) which M. Valenciennes examined, he found its structure cellular, similar to that of Amia. Thirty species.

GENUS IV. EXOCETUS, Linan. (Sub-Family, Exocetinae, Bonap.) Recognizable at once by the large pectoral fins that are capable of being used as wings or parachutes. Head and body scaly, with a scaly keel on each flank. Head flattened above and on the sides. Dorsal opposite the anal. Eyes large. Premaxillaries without nasal pedicels, forming the border of the upper jaw; maxillary not soldered to the premaxillary, but having nearly the same position as in Belone. Gill-openings behind the opercular ceca, juxtasold with small pointed teeth, composed of cement-dentine, and the pharyngeals with crowded teeth, having compressed crowns and several cusps, like those of Oppistodus, Acantilurus, and other genera. Branchiostegals ten to twelve. Intestine straight, without pyloric CHROMIDIDÆ.

This family is included by Müller among the Pharyngognaths with spinous rays in the fins. It is not treated of in the Histoire des Poissons, and the generic characters in the table are from Cuvier's Règne Animal, or from Rüppell's works. The members of this group agree with the Ctenoid Labroids in having only one nostril to each nasal sac.

SUB-ORDER II.—ACANTHOPTERYGII.

FAMILY I.—CHROMIDIDÆ, Bonap.

Chromisde, Moll. Lateral line interrupted. Teeth villiform. One dorsal, a single nostril to each pituitary sac.

GENUS I. CHROMIS, Cuv. General aspect of Labrus, with their lips, protrusible premaxillaries, pharyngeal bones, and the filaments of their dorsal rays; but the entire caudal and the soft dorsal and anal to a considerable height are scaly. Their teeth are disposed in two card-like bands on the jaws and pharynx, with, in front, a row of conical teeth. Branchiostegals six. Lateral line ceasing under the dorsal, and not recommencing on a lower level. Stomach excaec; two pancreatic ceca. The Roht of the Nile has no pancreatic cecum, but its stomach is excaec. Its dentition is that of the Mediterranean species.

GENUS II. CYCLES, Bloch, Schmidt. Have the body more elongated than Chromis, and their teeth in a broad band, and wholly villiform.

GENUS III. SAROTHERODON, Rüpp. General habit of Chromis. Both jaws armed with an outer row of slender chisel-shaped teeth, smaller at their insertion, wider at their edges, behind which a band of brush-like teeth. Palatines and tongue unarmed; at the pharynx fine brush-like teeth, on a single three-cornered plate below, and two roundish transverse plates above. Four gills. Opercula without scales; pretty large scales on the body. Lateral line interrupted. A dorsal fin extending along the whole back, two-thirds of it supported by spines; three spines in the anal; ventrals behind the pectorals. Guinea coast.

CTENO-LABRIDÆ.

A small but very natural family separated from the Scienidæ by their united pharyngeals, and the want of muciferous cellular structure of the bones of the skull. They are denominated in the Histoire des Poissons "Scienoides à moins de sept rayons branchiaux et à ligne latérale interrompue;" and are there said to be beyond the bounds of the Linnaean genus Scienia, and to have analogies with the Labroids. They are small fishes, of a peculiar rounded oval form, and clothed with large scales, a well-marked family likeness pervading the several genera. Their strongly ciliated scales separate them from the true Labroids, whose scales are cycloid. They are edible, but they do not form the objects of special fisheries, not only from their want of size, but because they do not assemble together in numbers. The Glyphisodon and others of the family are prettily banded, and show a pleasing combination and variety of colours.

FAMILY II.—CTENO-LABRIDÆ, Moll.

Compressed oval or oblong fishes, with the head forming part of the general elliptic profile. One dorsal spineless in front; anal also spineless in front, placed with the dorsal on the posterior curve of the oval. Tail between the vertical fins short and moderately high. Scales ctenoid. Air-bladder closed, without appendages. Ovarium closed, with an excretory duct behind the anus. Cranial not cavernous in its outer walls. A single nostril to each pituitary sac.

GENUS I. CAPODON, Schleg. Teeth card-like on both jaws, before which a row of bigger ones; the three fore teeth of the premaxillary on each side being large cutting teeth; front mandibular tooth very large, and pointing backwards; behind it one somewhat smaller; in the middle of the limb of the mandible there stands a large tooth arched backwards, and then follow some more card-like teeth. Branchiostegals five.

GENUS II. AMPHIPIRON, Schmidt. Body oral, compressed. A single dorsal. Lateral line terminating under the end of the dorsal. Head obtuse; uniserial, small, conical, obtuse teeth on the jaws; palate edentate. Five branchiostegals. Preoperculum, operculum, suboperculum, and interoperculum denticulated strongly, and striated on their surfaces. Air-bladder simple. Sixteen species.

GENUS III. PREMNAS, Cav. Form that of an Amphiprion, with interrupted lateral line, and obtuse uniserial teeth, but the opercular pieces are less strongly toothed, and the suborbital scales much more armed, producing under the eye one or two large spines pointing backwards. A few denticulations exist on the ascending edge of the preoperculum, and on the border of the suboperculum; but the opercular pieces are not strongly streaked on the surface, as in Amphiprion. Stomach globular; small; three pancreatic ceca; large globular air-bladder. Three species.

GENUS IV. POMACENTRUS, Lacépé. Form oblong. Head obtuse; incisoral uniserial teeth. Preoperculum denticulated; operculum entire on the border, and without spines; suborbital often toothed. Lateral line ending under the soft portion of the single dorsal; four or five branchiostegals. Twenty species.

GENUS V. DASYLUS, Cav. Resembling Pomacentrus, but the mouth, instead of being trenchant, are in a villiform band, with strong conical teeth in the outer row. Three species.

GENUS VI. GYPSIUSDORON, Lacépé. Having a strong resemblance to Pomacentrus, but the preoperculum is more denticulated. Body compressed, oval, covered as well as the head with large scales. Profile rounded. Mouth small; teeth on the jaws only, uniserial, close together, narrow and straight, trenchant at the crown, and often notched. Lateral line ending under the end of the dorsal. For the most part thirteen dorsal spines (rarely twelve), each with a membranous filament at its tip; two anal spines (rarely three). Stomach very large, excaec; three thick pancreatic ceca; ovaries discharging by a tube behind the anus. Thirty species.

GENUS VII. ETROPLUS, Valenci. Oval compressed form of Glyphisodon. Eye more elevated than in that genus, and the suborbital scale-bone large and not scaly. Snout also destitute of scales. Dorsal (eighteen or eighteen) and anal spines numerous (eleven to thirteen). Three species.

GENUS VIII. HELASSE, Cav. Resembling Glyphisodon in the oval compressed body. Small mouth. Entire or smooth-edged preoperculum. Large scales and short lateral line, and in the number of spines in the dorsal and anal, but having the teeth of Dasyillus. Branchiostegals five, rarely six.

CYCLO-LABROIDS.

The name Labrus applied to a fish is cited by Pliny as occurring in a passage of Ovid which has not been preserved, and the kind of fish it was used to designate cannot now be ascertained. The name was widely and vaguely applied by modern ichthyologists until Cuvier gave the precise characters of the genus which it now distinguishes. Several species occur in the British seas; none of them prized as an article of diet. The Tautog (Tautoga nigra) of New York, however, is a fish in great request for the table, and sells at the rate of $8 lb. for a dollar. It is tenacious of life, and is kept in stews to fatten. In great colds it becomes torpid, and will not eat. When the dogwood (Cornus florida) comes into flower the Black Tautog is in season.

The Epibulus seizes insects by suddenly thrusting out its mouth, and engulphing those that come within the scope of the elongated tube; at least so says Renard; and the accounts of this fish shooting drops of water at its insect prey, like the Chelmonos, does not appear to be based on correct observation. *Scarus* was the name given by Forskal to a group of fishes resembling the *Labri* in all their characters except in dentition, their teeth being incorporated with the substance of their jaws to form convex bones like those of the Tetraodonts. The researches of Cuvier prove fully that the fish so named by the ancients was truly of this genus. It was held in high repute either for the address attributed to it of skilfully withdrawing other fishes from the nets in which they were inclosed, or because the epicures greatly esteemed its intestines, or on account of the vast expense incurred in endeavouring to multiply it on the Italian coasts, that it might administer to the extravagant luxury of the world's capital. Aristotle has several passages respecting its rumination. His assertions have been repeated by Pliny, Ælian, and others, without examination; and Ovid and Oppian have spoken of it as a matter beyond doubt, yet no one has verified the observation of Aristotle. It passed also among the ancients as a fish that had a voice; and Suidas says that it produced sounds by ejecting water in blowing, and that it could not make itself heard when it was deep in the water. Athenaeus, quoting Seleucus as his authority, states that the *Scarus* is the only fish that sleeps and is never taken in the night. Ælian says that it is the most ardent in love of all fishes, and that many males may be enticed into the nets by the pursuit of a female attached to a line. But still it was the most prudent of fishes, and the most active in showing friendship for its companions. If one was caught by a hook, the others endeavoured to cut the line; or if entrapped in the meshes of a net, they tried to drag it out by the tail!

"Sic et Scarus arte sub undis, Contextam si forte levì de vimine nassam, Incilit, assamantaque dolo tandem pavet escam. Non audet radili obliqua occurrere fronte. Averus crebro veniens sed verbere cauda, Laxans subsecutur, tutumque evadit in aquam."

OVID.

It was most plentiful and of the best quality in the Carpathian Sea, between Crete and Asia Minor, but was not unknown even in early times on the Italian coast, though Columella says that it seldom passed beyond Sicily in his day. But in the reign of Claudius, according to Pliny, Optatus Eliphius brought it from the Troad, and introduced it into the sea between Ostium and Campagna. For five years all that were caught in the nets were thrown into the sea again, and from that time it was an abundant fish in that locality. In the time of Pliny it was considered to be the first of fishes (*Nunc Scaro datur principatus*); and the expense incurred by Eliphius was justified, in the opinion of the Roman gourmands, by the extreme delicacy of the fish. It was a fish, said the poets, whose very excrements the gods themselves were unwilling to reject. Its flesh was tender, agreeable, sweet, easy of digestion, and quickly assimilated; yet, if it happened to have eaten an Aplysia, it produced *cholera morbus*. In short, there is no fish of which so much has been said by ancient writers. In the present day the *Scarus* of the Archipelago is considered to be a fish of exquisite flavour; and the Greeks still name it *Scaro*, and eat it with a sauce made of its liver and intestines. It feeds on fucus; and M. Valenciennes thinks that the necessity for masticating its vegetable diet thoroughly, and the working of it with that intent backwards and forwards in the mouth, may have given rise to the notion of its being a ruminant; and it is certain that its aliment is very finely divided when it reaches the stomach. The adjoining woodcut represents *Callyodon chlorolepis*, a fish of the Australian seas, and number 56, gives views of the teeth of the same species. Woodcut 86 is a representation of *Odax lineatus*; and figures 25, 38, and 39, are views of *Classification—Pharyngognaths*.

Labroid scales. The family of *Amblyocidae* was constituted by Agassiz for the reception of a single genus of fishes that frequent the western coasts of North America.

**Family III.—Cyclo-Labridæ**, Müll.

oval, elliptical, or oblong scaly fishes more or less compressed, generally with a proportionally high parallel-sided tail between the vertical fins. Scales cycloid. A single dorsal supported in front by spinous rays, which have frequently minute serrated processes behind their points. Jaws covered by fleshy lips; palatine bones toothless. Three pharyngeal bones, viz., two above and one below, armed with teeth, which are in some species pavement-like, in others lamellated, and in others pointed. No pancreatic cecae; a closed, simple air-bladder; shut ovisacs, with an efferent tube behind the anus.

**Analytical Table of the Cyclo-Labridæ** (Dum.)

Cheeks scaly; preoperculum crenulated.

Dorsal scale at the base.

Mouth protostomate; teeth even..............Clepticus 7. Mouth not protostomate; teeth unequal...Cossyphus 2.

Dorsal not scaly.

Mouth protostomate.

Dorsal with short soft rays.

Scales very large.........................Epibulus 21. Scales of ordinary size....................Coricus 6. Dorsal with long filaments.................Iachnolaimus 8.

Mouth not protostomate.

Teeth equal to one another..............Chenilabrus 3. Teeth unequal..........................Acantholabrus 5. Dorsal scaly.............................Ctenolabrus 4.

Cheeks scaly; preoperculum not crenulated.

Dorsal very long.

Scales very large; teeth uniserial..........Cheilinus 18. Scales of ordinary size....................Suboperculum denticulated..............Malapterus 12. Suboperculum very entire..................Malacanthus 10. Dorsal of ordinary length; rays tasseled...Labrus 1.

Cheeks scaleless.

Snout abnormal, like a beak..............Gomphosus 15. Teeth unequal, reclining, diverging.......Anampses 14. Teeth equally curved......................Chelio 11. Scales very large; posterior..............Tautoga 9. Preorbital denticulated....................Julis 13. Preorbital smooth-edged...................Nyricthys 16. Profile curved, convex....................Novacula 17.

Genus I. Labrus, Linn., Artedi. Lips large, thick, and as if double, 6 branchiostegals. Upper jaw generally considerably protostomate; teeth on the jaws simple, conical in one or more rows. Pharyngeal cylindrical, smooth, and rounded on the crowns. No spine on the preopercular bone. Lateral line almost straight, continuous. Cheek and opercular scaley. Thirty species.

Genus II. Cossyphus, Cuv. and Valenciennes. Maxillaries wide and thick. Behind the exterior row of pointed teeth, small, round, granular teeth crowded together. Opercular pieces scaley. Vertical fins sheathed in scales which rise and fall with the rays, but do not form so deep a sheath as those of the Percoids or Sparids. Almost all have distinct crenatures on the ascending border of the preoperculum, but in some these appear at the angle of the bone only, and are very feeble. Fifteen species. Genus III. Chenilabrus, Cuv. Upper jaw not protractile; preoperculum deeply toothed; lips thickly fleshy; teeth conical, uniseriatus, without the granular band of Corvulinae, and also without the scale sheathing of the head. The continuous lateral line and cycloid scales distinguishing them from Chenilabrus and Chelidra. Thirty-six species.

Genus IV. Chenilabrus, Cuv. and Valenci. A band of villiform teeth behind the outer row of conical teeth on the jaws. Other characters those of Chenilabrus, such as the finely denticulated preoperculum, three anal spines, &c. Ten species.

Genus V. Acantholabrus, Cuv. and Valenci. Dentition of Chenilabrus, but with numerous anal spines, representing the Percoidea Centrarchus. Six species.

Genus VI. Coricus, Cuv. Conical jaw teeth in one row, as in Chenilabrus; jaws greatly protractile, like those of the Menticirrhus. Premaxillaries with long pedicels, and limbs which are thrust out when the mandible is depressed. Preoperculum rounded at the corner, denticulated on the ascending border, but having a smooth lower line. Pharyngeal teeth small, round grains crowded together. Short intestine; stomach siphonal, without dilatation; no pancreatic ceca. Distinguished from Epibulus by its continuous lateral line; representing the Menoid Swarts and Gerres. Four species.

Genus VII. Clepticus, Cuv. Protractile mouth, withdrawing beneath the vault of the preorbital; denticulated preoperculum; continuous lateral line. Teeth in one row, few, and very small; pharyngeal teeth lamellated, the plates serrated. Vertical fins covered in great part by scales like those of the body. One species.

Genus VIII. Lachnolaimus, Cuv. Resembles Labrus in the lips; in general form; in the membrane which descends from the preorbital; in the scaly cheeks, and in the filamentous tips of the dorsal spines; but the tips of the anterior dorsal spines are flexible. Lateral line continuous. Anterior teeth strong, curved, and standing forwards, followed by a series of small teeth of even height. The pharyngeals, instead of being wholly covered with pavement-like teeth, as in Labrus, are only partially so, and the upper part of the bone being clothed with velvety membrane. No pancreatic ceca. Six species.

Genus IX. Tautogla, Mit. Labroids distinguished by a double row of strong conical teeth on both jaws, and the extent of thick, scaleless integument on the face, which reaches to the operculum, suboperculum, and interoperculum, and even on the preoperculum the scales are few. Branchiostegals five. Lateral line continuous. Nine species.

Genus X. Malacanthus, Cuv. Resembling Corvulinae in the length of the dorsal and anal, and in the rays of these fins being nearly as flexible, but allied to Lachnolaimus by scaly cheeks, and a continuous lateral line. The proper generic character is the long dorsal, with only three or four simple rays in front, the others being branched. Body highly compressed, long. Scales small. Anal nearly as long as the dorsal. Mouth tolerably large; lips fleshy; a row of teeth on the jaws; large, and curved in front, much smaller towards the angles of the mouth. Palate and tongue smooth; upper pharyngeal teeth card-like; under pharyngeal teeth in some species wholly card-like, in others partly so, partly pavement-like. A pretty strong spine at the angle of the operculum. Stomach siphonal; no pancreatic ceca. Two species.

Genus XI. Cheilio, Comm. Premaxillaries widening internally into a granular osseous plate peculiar to this genus among the Labroids. Exterior row of teeth triangular, compressed, and trenchant, like those of some Sphoeroides or Cyprinodon; the symphysial pair hooked, and longer than the others, which are of equal height among themselves, and in the interspaces between all these teeth there are small conical ones. The lateral line is continuous; and there are a few scattered scales on the cheeks. Fin rays flexible. Eight species.

Genus XII. Malapterurus, Valenci. Combines many of the characters of Malacanthus and Cheilio, having the flexible rays of Cheilio, teeth of Labrus, scaly operculum of Malacanthus, but not the opercular spine. One species.

Genus XIII. Julis, Cuv. Lateral line continuous; stiff and pointed spines in the dorsal. Head entirely naked, that is to say the suborbital chain, preoperculum, and other bones of the gill-cover, the under surface of the head, and the jaws, are destitute of scales. Teeth conical in the outer row, longer and stronger the nearer the symphyses; within there are some granular teeth, largest in the old fish, being indications of teeth incorporated with the bone, as in Cheilio; and more fully shown in Scorpaena. Some species have a canine at the corners of the mouth pointing forwards, forming the genus Halichoeres of Hippolyte. Pharyngeal teeth as in Labrus. One hundred species.

Genus XIV. Anampses, Cuv. Two teeth on the upper jaw, one on each side of the symphyses, turning from each other, flattened longitudinally; chisel-shaped at the crown and trenchant; the mandibular pair more conical, yet a little flattened at the point; pharyngeals of Labrus for bruising. Branchiostegals six. General form that of one of the higher bodied Julis. Head naked. Lateral line continuous. Six species.

Genus XV. Xenichthys, Lacép. (Holos, Comm.) Body oblong, compressed. Scales large. Head quite naked; eye small; nostrils near the orbit; muzzle slender, elongated, cylindrical; orifice of the mouth formed by the premaxillaries and mandible. Uniseriatus teeth on the jaws, the anterior ones longer; pharyngeal teeth pavement-like, as in Labrus. Gill-covers approaching one another under the throat; gills-openings narrow. Branchiostegal membrane adherent to the isthmus; branchiostegals six. Dorsal and anal but slightly elevated, and of uniform height. Lateral line branching and deflected near the caudal. Stomach and oesophagus straight; no pancreatic ceca; long, narrow air-bladder. Three species.

Genus XVI. Xyrichtys, Valenci. Form that of a Labrus, except that the profile of the face is almost vertical, with the eye high up; this is owing to the growth of the bone directed downwards, while the mandible of ordinary length is horizontal. The resulting aspect is peculiar. Many characters common to it and Labrus or Julis. Head naked, and, from compression, trenchant in the face, which is sustained by the nasal bone. Dorsal long and of uniform height. Teeth in one row, longest near the symphyses; pharyngeal teeth small, pavement-like; palate and tongue smooth. Lateral line interrupted generally as in Scorpaena, but the tubes on each scale simple. A species of double lip is formed by the edge of the preorbital, which descends to the corner of the mouth. Intestinal tube simple, without any stomachal dilatation, and without pancreatic ceca; air-bladder large, pointed anteriorly, rounded behind. Fourteen species. Two species have the three front rays detached as a separate fin, and form the only instance, except Novaculida, of a Labroid with two dorsals.

Genus XVII. Novacula, Valenci. Preoperculum scaly under the eye, with the mandible more ascending in other respects, like Xyrichtys. Generally the first two dorsal rays are somewhats detached from the others, and connected to them by basal membrane only. Six species.

Genus XVIII. Cheilinus, Cuv. Lateral line interrupted under the end of the dorsal. Lips thick; large, uniseriatus, conical teeth on the jaws. Large scales on the cheek; scales of the body broad and thin, advancing on the base of the caudal, but leaving the dorsal rays naked as in Labrus. Splanchnology also as in that genus, but the bones are green in some, if not in all the species, like those of Eulamprus. Twenty-four species.

Genus XIX. Chenilabrus, Cuv. Jaws armed with similar tapering stripes of teeth, succeeded posteriorly by small tufts of teeth; four stout conical canines in front of each jaw. Thick lips. Scales of the operculum and preoperculum of moderate size; on the body the scales are larger. Lateral line interrupted. Spines of the dorsal and anal strong and pointed. Java.

Genus XX. Ctenilabrus, Schleg. A toothed preoperculum; an interrupted lateral line. Scaly gill-cover. Ventrals prolonged into filaments. Branchiostegals five.

Genus XXI. Ephiphius, Cuv. Protractile mouth, the mechanism of which differs from that of Coricus. The nasal pedicels of the premaxillaries play in grooves of the skull, and reach back to the occiput, while the dentary bone branch is attached by a long ligament to the lower end of the maxillary bone, and, consequently, when the mouth opens, draws forward that end of the maxillary together with mandible, which is also connected to the same end of the maxillary. The hypotympanic and mesotympanic unite to form a lever, and assist in this movement. The scales are very large, and cover the cheeks, but are there embedded in the skin, and the face is naked. The large jaws, with the projection of the hypotympanic and angular portion of the mandible, give a peculiar aspect to the fish which otherwise resembles a Glaucostomus. Branchiostegals five. Lateral line interrupted. One species.

Genus XXII. Scarus, Forsk. Labroids of oblong and rather massive form; lateral line interrupted under the end of the dorsal, and remaining low down. Large scales extending to the gill-covers and cheeks. Teeth in the palatine bones of Tetraodon, each divided into halves by a median suture. The teeth are incorporated with the bone, and shine through the glaze, and are in crowded quincuncial order; the oldest form the trenchant borders of the jaw, and as they wear away they are succeeded by the lower pulps, new pulps developing at the base of the jaw to keep up the succession. In some species the quincuncial surface is even and polished, in others it is granular from the prominence of the crowns of the teeth, and in some a few pointed canines protrude from the angle of the upper jaw, or from other parts of it. Pharyngeal teeth trenchant and standing up like verticle tiles, producing in the using, narrow, projecting ellipses of dentine surrounded by enamel; the base of each tooth is osteodentine, and it is bound to the others by cement. Each of the superior pharyngeals carries two or three longitudinal ranges, the number varying with the species; the single under pharyngeal is fixed by a thin vertical plate in the angle formed by Order IV.—Anacanthini, Muhl.

Endo-skeleton ossified; exo-skeleton in some as cycloid, in others acrodont scales. Fins supported by flexible or jointed rays; ventral beneath the pectorals, or none. Swim-bladder without air-duct in the Gobidae; absent in Ophididae, Echeneidae, Macrouroidea, and Pleuronectidae.

Sub-Order I.—Apodese.

Family I.—Ophididae.

Gobus-like fish without ventrals. Body elongated, more or less dagger-like posteriorly; the tail surrounded without a break by the vertical fins.

Genus I. Macharium, Rich. Anus at the termination of the first third part of the length of the fish. Body scaly. Mandible destitute of a barbel; unicarinal teeth on the jaws. Dorsal beginning somewhat behind the pectoral; anal occupying two-thirds of the length of the body. Six branchiostegals. Lateral line running under the tenth ray of the dorsal. No swim-bladder. Two species.

Genus II. Ophidium, Lin. Anus at the termination of the first third part, or of the half of the length of the fish. Body scaly. Two pair of barbels attached beneath the point of the glosso-hyal (or lingual) bone. A swim-bladder. Small sword-shaped fish, with lowly developed dorsal and anal fins, supported by simple rays only. Air-bladder large and oviform, with three proper osicles, the middle one of which is moved by a peculiar muscle. Six species.

Genus III. Gymnalis, Reinb. (Cephalophis, Kaup.) Ophidia without barbels, and destitute of scales; resembling the proper Ophidia in the blunt head. The vomerine teeth do not project forwards, but lie deep in the palate. Anus situated in the fore part of the fin. Pectorals and vertical fins moderately developed. They are distinctly separated from each other so that the anus is not in the pectoral region, but farther back. The body also is less slim, and the tail not so much dagger-like. Two species.

Genus IV. Fierrafer, Cuv. (Echidnae, Thomp.; Oxybeles, Rich., Bleek.) Anus in the pectoral region. Vomer projecting forwards, with blunt or laterally compressed teeth. Seven branchiostegals. No scales. Three species.

Genus V. Enchelophis, Muhl. Abrachial as well as apodial; anus behind the gills. Six branchiostegals.

Gadoids.

This is a most important family, and the fisheries established for the capture of its various members have, more than any other tribe of fishes, been the means of forming great numbers of hardy and able seamen. Its members live in cold or temperate climates, and constitute a very important article of fishery. The greater number are considered wholesome, and form a light and agreeable food,—the flesh separating easily by boiling into white flaky layers. The great sand-bank of Newfoundland is the most famous station of the Cod fisheries, and is resorted to by English fishermen, who chiefly use the hook and line. The fish abound in this place probably on account of the great quantity of the smaller animals which serve as food, viz., mussels, clams, &c.

Morus vulgaris, the common Cod (la Morne, Fr.; Kabelian, Germ.), measures from two to three feet in length. The back is spotted with yellowish brown. It inhabits the whole Northern Ocean, and occurs in vast profusion. This fish dwells in salt water only. It is not found nearer the equator than the 40th degree of latitude. The weight of the common Cod varies from 12 to 80 or even 100 pounds. It is extremely voracious, and its digestive powers are seemingly very great. It feeds upon smaller fishes, such as Herrings, on Mollusca, Worms, and Crustacea, and even on the young of its own species. It has a strong, muscular stomach, and is said to possess the power of rejecting by the mouth substances, such as wood, &c., which it finds indigestible. In spring it comes nearer the shore in order to deposit its spawn. This happens in January in England, in February in Norway, Denmark, and Scotland, and in March in Newfoundland. One female is said to contain from four to nine millions of eggs! The most extensive Cod fisheries... Classification—Ana- canthus.

On our coasts are off the Western and Shetland Isles, but they are still greater in more northern countries. The Cod has been fished on the coast of Sweden since the year 1368 by the inhabitants of Amsterdam. The English resorted to the fisheries of Iceland before the year 1415; and it is stated that in the year 1792, 200 French vessels, of a burden of 191,153 tons, were employed in the Cod fishery. Every year more than 6000 European vessels are engaged in this fishery.

The flesh of the Cod has a good flavour, and may be easily preserved. The tongue, salted and dried, has been considered a great delicacy. The gills are preserved and used as bait. The liver is eaten, and of late years the oil it yields has brought a high price owing to its importance as a medicine. The swimming-bladder affords a very good isinglass. This important species constitutes a principal article of food to the inhabitants in some parts of Iceland, Norway, and other northern countries. In a dried state it is also much used in some papal kingdoms of the south. In the neighbourhood of the Isle of Man, and elsewhere, there is a variety of the Cod named the Red or Rock Cod, the skin of which is of a brightish vermilion colour. Its flesh is much esteemed.

*Morrhua eglefinus*, the Haddock (*Egrefia*, Fr.; *Schollfisch*, Germ.), is as well known, and almost as important, as the Cod in this country; it is of a smaller size, usually eighteen inches long. The back is brown, the belly silvery, and the lateral line black. There is a blackish spot behind the pectoral fin, which tradition assigns to the impression of St Peter's finger and thumb, when he took the tribute money out of the mouth of a fish, the inventors of the legend never adverting to the improbability of a marine fish living in the fresh-water lake of Gennesaret. The Haddock is found, like the Cod, in the Northern Ocean, but does not enter the Baltic. It annually approaches the British shores in February and March, in order to deposit its spawn. The regularity with which it reappears in some districts, on a stated day, is quite remarkable. On the coast of Yorkshire, since the year 1766, it has made its annual appearance on the 10th of December. To this place it comes in such numbers as to form an immense shoal 3 miles broad, and extending 80 miles in length—from Flamborough Head to the mouth of the Tyne. It is in autumn that they visit the shores of Holland and East Friesland, and the neighbourhood of Heligoland. The Haddock frequents our coasts during the greater part of the year, although the largest are taken in the winter. Its flesh is generally best in the months of May and June, and is greatly superior on the east coast of Scotland than when taken in the southern parts of the English Channel. On the coast of Hampshire it is a very inferior fish.

*Morrhua collarias*, the Dorse, is smaller than the Haddock, resembles the Whiting in taste, and is by many considered to be the best fish for the table of all this family. It is in great request on the coasts of the Baltic. It frequents the mouths of large rivers, and ascends them with the salt tide in June. The *Morrhua lusca* and *barbata*, Bib and Whiting Pout, are considered by one so well acquainted with the British fishes as Mr Yarrell, to be but one species, and are well known on the English coast, being brought in considerable quantities to the market. They are in best condition for the table in November and December.

*Merlangus vulgaris*, Whiting (*Merlan*, Fr.), is valued on account of its abundance, and the wholesomeness and fine flavour of its flesh. Its fishery lasts the whole year, but is most plentiful in January and February, and is generally carried on within a mile or two of the shore. *Merlangus carbonarius*, Cole-fish (*Kohlfisch*, Germ.) The flesh of the young is rather delicate; that of the adult is somewhat leathery, but it is used when salted and dried, like the Cod. This is the *Podley*, *Silloch*, *Cuddy*, &c., of our coasts. The young swarm along the British shores, and form a frequent sustenance of the lower orders of the Western Highlands. On one occasion we killed 33 dozen with the rod in a few hours, using a line with 6 small flies. By giving the line one or two additional turns through the water, we frequently pulled 6 ashore at once. It even constitutes an important article of exportation from our northern coasts. In Norway the poor feed upon it; and oil is made from its liver. The adult fish is taken principally in summer; it deposits its spawn in this country in February and March. The Coal-fish is found in the North Atlantic and Pacific Oceans; and sometimes, though very rarely, in the Mediterranean Sea,—for example, near Nice. *Merlangus pollachius*, the Pollock or Pollack, about 18 inches long; resembles *M. carbonarius* in its general form. Its flesh is considered better than that of the Coal-fish, and inferior only to that of the Dorse and Whiting; it inhabits the Atlantic, and is gregarious. It is commonest on the coasts of Norway and the north of England, and sometimes occurs in the Mediterranean in winter. It is easily caught with a white fly.

Of the *Merluccius vulgaris*, or Common Hake, great numbers are taken in the ocean, and in the Mediterranean. On the coasts of the Mediterranean it is called Merlan or Whiting; and, when dried, it receives in the north the name of Stock-fish, in the same way as the Cod. It is said to be very abundant in the Bay of Galway, on the west of Ireland, and at Penzance in Cornwall. The flesh is white and flaky, and its liver is considered a delicacy.

The *Brosmius vulgoris*, Tusk, or Torsk, is common in the Shetland seas, but seldom comes so far south as the Firth of Forth. It is a most excellent fish for the table when newly caught, being far superior to the Cod, but rarely appears in the southern markets. It cures well. *Mola*, or *Lota molua*, is the only fresh-water fish of this family which exists in England, and is very local, being confined to a few rivers mostly of the midland counties. It is named the Barbot and Coney-fish, and its flesh is said to be good. One, or perhaps two species frequent the northern waters of the American continent, but their flesh, though wholesome, is lightly esteemed in a country which abounds in Coregoni and Trout of the richest flavour. The roe, which is remarkable for the smallness of its eggs, makes a substantial bread when pounded and mixed with a proportion of flour. The American fish is named Methy, and furnishes names for many rivers and lakes of that country. It is voracious, and feeds much on fresh-water Cray-fish.

The Gadoid family is scarcely known near the equator, but reappears again in the higher southern latitudes in the same generic forms though differing in species, and doubtless fisheries of these useful fishes will hereafter be established on the Australian coasts, when the submarine sand-banks come to be known, and the increase of population raises a greater demand for fish. The subjoined woodcut represents the *Lota breviceps* from the Bay of Islands, New Zealand.

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**Sub-Order II.—Thoracici.**

**Family I.—Gadidae.**

Body moderately elongated. Scales small, soft. Head naked. Analytical Table of the Gadidae (Dum.)

Dorsal single. Vertical fins separate......................... Bromius 7. Vertical fins united.......................... Brotula 8.

Dorsals several. Dorsals two. Barbels three; one rostral.................... Motella 6. Barbels one. Jugulars of many rays......................... Lota 5. Jugulars of one forked ray.................... Physus 10. Barbels none; one anal....................... Merluccius 4.

Dorsals three. Anal fins two. Barbels conspicuous.......................... Gades L. Barbels none................................. Morhina C. Merlangus 3.

Genus I. Gadus, Linnaeus. (Morhina, Cuv.) Three dorsal fins; two anal; a symphysial mandibular barbel.

Genus II. Garicus, Guich. Resembles Morhina in the fins, but the barbels are wanting, as in Merlangus. Body elongated, compressed. Head small, scaleless; jaw teeth pointed, ranged in many rows. Chiefly distinguished by the height of the eyes, and the want of vomerine teeth; the mandible projects a little. Algiers.

Genus III. Merlangus, Cuv. Gadi, without barbels.

Genus IV. Merluccius, Cuv. Two dorsal fins; one anal fin. No barbels.

Genus V. Lota, Cuv. Two dorsal fins; one anal fin. Barbels.

Genus VI. Merluca, Cuv. Number of fins as in Lota, but the first dorsal scarcely perceptible.

Genus VII. Bromius, Cuv. A single long dorsal reaching very near to the caudal.

Genus VIII. Brotula, Cuv. Vertical fins uniting at the end of the tail to form one pointed fin.

Genus IX. Atelopuss, Schleg. Snout very thick over the mouth, which is protrusive beneath. A band of card-like teeth above and below; vomer and palatines toothless. Ventral on the throat one-rayed; a small dorsal over the pectorals; anal very long; caudal small. Japan.

Genus X. Physus, Artedi, Schmidt. Ventral of a single ray, which is often forked. Head large. A symphysial mandibular barbel. Two dorsals, the second one long.

Genus XI. Ranieps, Cuv. Head more depressed than in other genera of this family. Anterior dorsal almost concealed in the thickness of the head.

Genus XII. Echeneis, Rein. Body compressed, thicker anteriorly. Profile of head bluntly rounded. Tail uniform, tapering to a point. Scales minute, round, imbricated. Lateral line interrupted over the anus. Teeth acute on the premaxillaries, mandible, vomer, and palatines. Branchiostegals eight, the membranes uniting under the isthmus with a free edge; gill-openings very large. Ventral jugular, of one filiform ray, each very long; vertical fins united, without any distinction of the caudal; rays jointed, divided. A very thick, conical, three-pointed papilla projected backwards behind the anus. No pneumatic tube to the air-bladder. One species.

Macrourids.

This family consists of a single genus, which stands next to the Gadoids in the Regne Animal, and certainly has many portions of structure of a similar character, particularly the turning down of the edge of the suborbitars, but these bones are much more developed than in Gadus, and their reverted plates appear on the surface of the cheek covered with rough scales. The Macrourids are inhabitants of deep water like most of the Gadoids, and have not been discovered near the equator, though they exist in both the northern and southern hemispheres, and in the Pacific as well as Atlantic divisions of the ocean. Figures 30, 32, 33, and 34 represent the scales of several Macrouri, remarkable for their discal spines, but differing from the ciliated scales named Ctenoides. The subjoined woodcut represents Macrourus australis.

Family II.—Macrouridae.

Turbinals largely developed, forming, by apposition of their plates, a thin, high, medial crest, and a lateral wing-like process on each side; these, in conjunction with the reverted plate of the preorbital, support a more or less elongated snout, which is generally, perhaps always, acute. Body highest and fullest at the pectoral region, compressed and dagger-shaped posteriorly, or tapering to an acute point. Ventral, pectoral, and first dorsal, in a vertical line; first dorsal base very high; second and second dorsal long and even uniting at the point of the tail; third fin and distinction of caudal. Anal in the anterior quarter of the body. Teeth fine, villiform on the jaws; palatines, vomer, and tongue edentate; mouth horizontal, inferior behind the projecting snout; premaxillaries forming the border of the upper jaw, and protrude directly downwards, their long pedicels moving under a vault formed by the turbinals; maxillaries behind the premaxillaries, gliding partially under the reverted edge of the preorbital. Scales studded with acute spines, varying in form and number with the species. Eye large; head encased by the scaly surfaces of muciferous bones. Branchiostegals six. Stomach globular; numerous pancreatic ceca.

Genus I. Macrourus, Bloch. (Lepidoleprus, Risso.) Nine or ten species in the temperate and colder seas of the northern and southern hemispheres.

Remora Family.

The Echeneidae stand in Cuvier's Regne Animal next to the Discobolidae, but Müller has transferred the latter to Gobiidae, making them a subordinate tribe under the appellation of Cyclopidi, and associating with them generally the fishes that have disks which can be used as suckers. Bonaparte places the Echeneidae as a group subordinate to his Gedi. The absence of spinous rays seems to point out the Anacanthini as their most appropriate order, but the same reason might bring several Gobioid genera with them. One species, however, of Echeneis has bony compressed rays in the pectoral, terminated by a little crenulated disk, and some have considered the disk on the head in this genus to be a modified first dorsal fin.

The extraordinary power possessed by this fish (Echeneis remora), of adhering tenaciously to any flattish surface, was known to ancient writers, as well as to the curious inquirers of modern times. Pliny luxuriates upon it with his usual discursive verbosity, and the reader may possibly be amused by Philoemon Holland's translation of the passages in question—"Having so far proceeded in the discourse of nature's historie, that I am now arrived at the very height of her forces, and come into a world of examples, I cannot chuse but in the first place consider the power of her operations, and the infinitesse of her secrets, which offer themselves before our eyes in the sea: for in no part else of this Classification—Ana- canths.

Inasmuch as we need not seek any farther, nay, we ought not to make more search into her divinity, considering there cannot be found anything equal or like unto this one element, wherein she hath surmounted and gone beyond her own self in a wonderful number of respects. For, first and foremost, is there anything more violent than the sea; and namely when it is troubled with blustering winds, whirlpuffs, storms, and tempests; or wherein hath the wit of man been more employed (seethe out all parts of the known world) than in seconding the waves and billows of the sea, by sail and ore? Finally, is there ought more admirable than the inerrable force of the reciprocal tides of the sea, ebbing and flowing as it doth, whereby it keepeth a current also, as it were the stream of some great river?

"The current of the sea is great, the tide much, the winds vehement and forcible; and more than that, ores and sails withall to help forward the rest, are mighty and powerful; and yet there is one little silie fish, named Echeneis, that checketh, scorneth, and arresteth them all. Let the winds blow as much as they will, rage the storms and tempests what they can, yet this little fish commandeth their furie, restraneth their puissance, and, maugre all their force, as great as it is, compelleth ships to stand still: a thing which no cables, be they never so big and able as they will, can perform. She brideth the violence and tameth the greatest rage of this universal world, and that without any paine that she putteth herself unto, without any holding or putting hake, or any other means save only by cleaving and sticking fast to a vessell: in such a sort as this one small and poore fish is sufficient to resist and withstand so great a power both of sea and navie, yea and to stop the passage of a ship, doe they all what they can possible to the contrarie. What should our fleets and armadoes at sea make such turrets in their decks and forecastles? what should they fortifie their ships in warlike manner, to fight from them upon the sea, as it were from mure and rampier on firme land? See the vanitie of man! alas, how foolish are we to make all this ado? When one little fish, not above half a foot long is able to arrest and stay per force, yea, and hold as prisoners, our goodly tall and proud ships, so well armed in the beakehead with yron pikes and brazen tines; so offensive and dangerous to bough and pierce any enemy ship which they doe encountre. Certes, reported it is, that in the naval battaille before Actium, wherein Antonius, and Cleopatra the queene, were defeated by Augustus, one of these fishes staid the admirall ship wherein M. Antonius was, at what time as he made all the hast and meanes he could devise with help of ores to encourage his people from ship to ship, and could not prevail, until he was forced to abandon the said admirall, and go into another galley. Meanwhile the armada of Augustus Caesar, seeing this disorder, charged with greater violence, and soone invested the fleete of Antonius. Of late daies also, and within our remembrance, the like happened to the roiall ship of the Emperor Caius Caligula, at what time as he rowed backe, and made saile from Astura to Antium; when and where this little fish detained his ship, and (as it fell out afterward) presaged an unfortunate event thereby: for this was the last time that ever this emperor made his returne to Rome: and no sooner was he arrived, but his own soul-dours in a mutinie fell upon him and stabbed him to death. And yet it was not long ere the cause of this wonderfull state of his ship was knowne: for so soon as ever the vessel (and a galliance it was, furnished with five banckes of ores to a side) was perceived alone in the fleete to stand still, presentlie a number of tall fellows leapt out of their ships into the sea, to search what the reason might be that it stirred not; and found one of these fishes sticking fast to the very helme: which being reported unto Caius Caligula, he fumed and faired as an emperour, taking great indignation that so small a thing as it should hold him back perforse, and check the strength of all his mariners, notwithstanding there were no fewer than foure hundred lustie men in his galley that laboured at the ore all that ever they could to the contrarie. But this prince (as it is for certain knowne) was most astonied at this, namely, that the fish sticking only to the ship, should hold it fast; and the same being brought into the ship and there laid, not worke the like effect. They who at that time and afterward saw the fish, report that it resembled for all the world a smalle of the greatest making: but as touching the form and sundrie kinds thereof, many have written diversely, whose opinions I have set downe in my treatise of living creatures belonging to the waters, and namely in the particular discourse of this fish: neither doe I doubt but all the sorte of fishes are able to doe as much: for this we are to believe, that Porcellans also be of the same vertue, since it was well knowne by a notorious example, that one of them did the like by a ship sent from Periander to the Cape of Gnidos: in regard whereof, the inhabitants of Gnidos doe honour and consecrat the said Porcellane within their temples of Venus. Some of our Latin writers do call the said fish that thus staith a ship, by the name of Remora."

Another species, *Echeneis naucrates*, Linn., commonly called the Indian Remora, has usually twenty-two plates upon the head. In its habits it resembles the preceding; but it seems to be more frequent in the seas of India and America than in those of Europe. The manuscripts of Commerson, as quoted by Count Lacépéde, inform us that it is common along the coasts of Mozambique, where it is made use of in a singular way for the purpose of catching turtles. A ring is first fastened round its tail, and then a long cord is attached to the ring. When thus accouered, the fish, placed in a vessel of sea-water, is carried out in a boat; and as soon as the fishermen perceive a sleeping turtle, they row gently towards it, and throw the Remora into the water, with a sufficient length of cord. It seldom fails speedily to attach itself to the unconscious turtle, which by the tenacity of its adherence is immediately drawn towards the boat and captured.

**Family III.—ECHENEIDID.E**, Bonap.

Remarkable and peculiar in having a flat head occupied on the dorsal aspect by a laminated disk that forms an adhesive sucker by which the *Echeneis* can attach itself to ships or other fishes, most commonly to the large Sharks. Body elongated, tapering much towards the tail; scaly. Dorsal single, malacopectoral opposite to the anal. Eyes lateral. Mouth small, horizontal; mandible projecting; teeth on the premaxillaries and mandible villiform or fine card-like; a row of hair-like teeth on the edge of the maxillaries, which form the sides of the upper jaw; villiform teeth on the front of the vomer and the surface of that bone, and of the tongue rough. Branchiostegals eight. Stomach caecal, large; a wide, short intestine; swim-bladder. The lamina of the disk are spinous on the edges, the spines being in most species very short and slender; the number of laminae varies in different species.

**Genus L. ECHENESIS**, Linn.

**Flounder Family.**

Though the *Pleuronectidae* do not require the same armaments for deep-sea fishing that the Gadoids do, yet they are of great importance to our maritime population, and give employment to large bodies of fishermen at most parts of the coast. These fish abound in comparatively shallow water, where the bottom is sandy, though some of the largest, as the Turbot and Halibut, are taken further out to sea. As they feed habitually at the bottom, the Flounders are chiefly captured by trawlers. Mr Yarrell states that London alone pays £15,000 a-year to the Danes for lobsters to make sauce for the Turbots brought to the London market, which amount, according to the same authority, to 88,000 in a season. Pennant has particularly described the extensive Turbot fishery at Scarborough. There are three men in each of the fishing-boats, each man having three lines, and each line 250 hooks. All the nine lines are fastened together, and then extended to about three miles in length; they are laid across the current, and are allowed to remain for six hours before they are hauled in. This fish is called the Water or Sea Pheasant, by the French common people, on account of its fine flavour.

**Family IV.—PLEURONECTIDAE.**

Peculiar among fishes in showing a want of symmetry in the head, the eyes being turned to that side, which is uppermost when the animal swims, and is always darker-coloured than the other side. Body extremely compressed, so that the ventral and dorsal aspects are mere edges, the sides forming disks, round, oval, ovate, or elliptical, differently coloured, the paler one simulating the belly, and being beneath in the usual position of the fish. Dorsal extending along the whole back, and in some running forwards to the nostrils; anal fringing in the same way the ventral edge; jaws and ventrals generally unsymmetrical, being smaller on the pale side. Branchiostegals six. The presphenoid is twisted to one side, and the mid-frontal is one of the most distorted bones in the cranium of these fishes. There is no want of symmetry in the spinal column and its processes posterior to the scapular arch; the interneural and interchondral spines are in pairs, supporting one dermoneural or dermohemal spine. No air-bladder.

**Analytical Table of the Pleuronectidae (Dum.)**

| Body rhomboidal. | | |------------------|---| | **Dorsal over the eyes which are external.** | | | Teeth broad, trenchant. | Platessa. | | Teeth villiform. | Hippoglossus. | | **Dorsal over the upper lip; eyes sinistrals.** | Rhombus. | | Body oval, or much elongated. | | | Pectorals very distinct, on both sides. | Solea. | | Pectorals distinct on one side only. | Monochir. | | Pectorals wanting. | | | Vertical fins separated. | Achirus. | | Vertical fins united. | Plagiusa. |

**Genus I. Platessa, Cuv.** Obtuse, trenchant, uniserial teeth on the jaws; most frequently pavement-like teeth on the pharyngeals. Dorsal not coming further forward than the centre of the upper eye; caudal separated by intervals from the dorsal and anal. Form rhomboidal. Eyes generally on the right side. Pancreatic ceca three, small.

**Genus II. Hippoglossus, Cuv.** Fin of Platessa, with generally a more oblong form. Teeth card-like, often strong and pointed on the jaws and pharyngeals.

**Genus III. Rhamphus, Cuv.** Teeth on the jaws and pharyngeals villiform, or card-like, as in Hippoglossus, but the dorsal comes forward to the border of the upper jaw, and extends like the anal to near the caudal. Eyes for the most part on the left side.

**Genus IV. Solea, Cuv.** Mouth carved and turned almost wholly to the blind side of the head; teeth situated on that side only, finely villiform; form oblong; snout round, and almost always advancing before the mouth. Dorsal commencing at the mouth and extending like the anal to the caudal. Lateral line straight. Blind side of the head often garnished with cutaneous threads like villi. Intestine long, often doubled; no pancreatic ceca. In some the caudal is not distinct from the other two vertical fins. These form the genus Breviceps of Swainson, or Synopterus of Cuvier.

**Genus V. Monochir, Cuv.** Solea destitute of a pectoral on the blind side; mouth large; caudal fin almost imperceptible; vestige of one, the pectoral on the side of the eyes being very small.

**Genus VI. Achirus, Lacep.** Abrachial Soles, with the vertical fins distinct.

**Genus VII. Plagiusa, Brown.** Abrachial Soles, with the vertical fins united.

**Order V.—ACANTHOPTEROUS FISHES.**

This order, the most extensive of all for the variety of forms and number of species, includes fishes under every condition that a fish can exist, whether it be with regard to the freshness or saltness of the water it inhabits, its temperature, depth, altitude above the sea, or other circumstances. There is certainly some connection between the ciliated scales with which the great majority of fishes of this order are clothed, and the spinous terminations or serrated edges of many of the bones of the head and shoulder which appear on the surface, and assume more or less the conditions and functions of dermal productions. The ctenoid scale, however common it may be in the order, is not universal, and the first family, the Uranoscopes have chiefly cycloid scales. The absence of a pneumatic tube to the air-bladder is perhaps a more constant character, but the viscus itself is not always present. The ventral fins are, when they exist, placed, in the majority, near the pectorals.

**Order V.—ACANTHOPTERI, Mull.**

Endo-skeleton ossified; exo-skeleton as ctenoid scales. Fins with one or more of the first rays unjointed or inflexible spines; ventrals in most beneath or in advance of the pectorals. Swim-bladder without air-duct.

**Uranoscopidae.**

The Uranoscopes are remarkable for their power of raising their eyeballs out of their sockets, and of retracting them again within the level of the orbits. They frequent the bottom of the sea, and, like many ground fish, some of them have organs of touch developed in form of barbels, and they have also a peculiar membranous filament under the tongue, which they can protrude at pleasure. The Mediterranean Uranoscope was named Agnus and Callionymus by the ancient Romans, and Pliny says that the same fish was called Callionymus and Uranoscopus. Aristotle remarks correctly that the gall-bladder of this fish is attached to the right lobe of the liver, and is of greater size than in other fishes; and the dramatic poets referred to it proverbially when alluding to an angry man. Its gall was supposed to have some power of rendering the sight more clear, of removing deafness, and of depressing the fungus growths of old sores. The species are more numerous in the Australian seas than in any other quarter of the ocean. Trachinus has some resemblance in external characters to the Sclerogenaide, especially in the simplicity and thickness of the lower pectoral rays, and in the projection of the tips of the anal rays beyond the membrane, but they are distinguished by the second suborbital not crossing the cheek to the preoperculum. The Uranoscopes, indeed, make an approach to this peculiar structure, but in them the suborbital articulates with the upper limb of the preoperculum, and does not buttress its angle, as in the true Sclerogenaide. The projecting tips of the anal rays occurring in many ground fishes are seemingly organs of touch. The family generally, as here assembled, corresponds with Cuvier's group of Jugular Percoids, but we have brought into it Hemerocotes, which is placed at the end of the Gobioids, next Callionymus, in the Histoire des Poissons, and also an Australian fresh-water genus Gadopsis not described in that work. The internal structure of several of the genera must be investigated before the correctness of this grouping can be ascertained. None of the family are of importance as articles of food. The woodcut No. 46 represents Uranoscopus macropogon, an Australian species, which has no first dorsal; the head of Borichthys is represented by No. 45, drawn to show the branching mucoducts; a scale of Gadopsis is shown by No. 26; and one from the lateral line of Hemerocotes by No. 43.

**Family I.—Uranoscopidae.**

Trachinidae, Bonap. Ventrais composed of a spine and five jointed rays, situated before the pectorals (in Trichodon and Siligo a little behind the pectorals). Scales cycloid, or wanting, acanthoptery- Few families of fish have been more fully investigated by ichthyologists than this one, yet the vast number of species that belong to it is embarrassing to students, and the strong external characters which many possess have withdrawn the attention from the more important varieties of structure, to slight serratures of the opercular bones, or the greater or smaller size of the scales on some parts of the head, and other slight modifications of the surface, which are obvious to the eye indeed, and therefore useful for subdividing a genus containing many species, but are not of themselves sufficient to establish generic groups or other divisions of higher importance. These comparatively unimportant external characters have however been too generally employed for this purpose, and the importance of the want of teeth on the roof of the mouth having been too rigidly insisted upon, as a variety of structure of family rank, has caused the wide separation of species nearly connected by aspect, habits, and general conformation. Many Percoids have been placed with the Scienoids merely because the minute teeth of the palate are early deciduous. On the other hand, forms have been brought together by a few technical characters which have comparatively little natural affinity, and an ichthyologist who is intimately acquainted with ichthysc anatomy has a wide field before him where he may render great service by reducing the at present heterogeneous assemblages to more fitting order. In the mean time we shall, with a few exceptions, follow our principal authorities—Müller for the general arrangement, and the Histoire des Poissons for the generic groups. We have found it convenient to introduce into our table, as distinct families, the Percoids of Cuvier which have more or fewer branchiostegals than seven; or whose ventrals vary in composition from the normal number of five articulated rays, or depart from their usual position in this family under the pectorals. The useful analytical table given in the Histoire des Poissons, abbreviated by the removal of these groups, will remain as follows:— The common Perch (Perca fluviatilis, Linn.), one of the most beautiful of the fresh-water fishes of Europe, is too familiarly known to require description. It inhabits both lakes and rivers, but shuns salt water. As an article of food it is still in some estimation, although the character given of it in that respect by Ausonius is higher than accords with modern views. The female deposits her ova, united together by a viscid matter, in lengthened strings, a peculiarity noted by Aristotle. The number of these eggs sometimes amounts to nearly a million. The Perch occurs over all Europe, and most of the northern districts of Asia. Pennant alludes to one said to have been taken in the Serpentine River, in Hyde Park, which weighed nine pounds. But even one half of that weight would be regarded as extraordinary, and Pennant reports the fact on the authority of another.

The fish here represented is the Labrax lupus, Basse or Sea Perch, a fish of a chaste and pleasing aspect, though destitute of the more strongly contrasted colours of the fresh-water species. Its upper parts are gray, with bluish reflections, which gradually shade away into a silvery whiteness on the under surface. The pectoral fins are slightly tinged with red. It occurs along the Dutch and British shores, but is much more abundant in the Mediterranean. It is a voracious fish with a remarkably large stomach, and received from the ancient Romans the appropriate cognomen of lupus. By the Greeks it was highly esteemed: Archestratus, even termed a large kind taken near Milet, "offspring of the gods." They attributed to the lupus a tender regard for its own safety; and Aristotle says that it is the most cunning of fishes, and that when surrounded by a net it digs for itself a channel of escape through the sand.

There is little that calls for attention from the other Percoids with two dorsals. Though interesting from the variety of forms they display, we must leave these to be studied in their leading features as given in the annexed table, and give the space we can allot to species of more importance, either objects of commerce or of large fisheries, or from the associations connected with them.

In the Histoire des Poissons, the Percoids with a single dorsal form a second great division of the family; and, were it not for the break in the close affinities between the two groups that would be caused by making this division a separate family, the number of species that it contains might render such a proceeding expedient as a mere matter of convenience. Cuvier remarks that the Percoids, in which the spinous portion of the dorsal is connected with the soft one by a sufficiently even border, is much more numerous in species than the typical division with two dorsals; and he found it necessary, therefore, in arranging them, to have recourse to characters of a sufficiently minute kind. Bloch drew his from the denticulations of the preoperculum and the spines of the operculum; but he has frequently used them without judgment, and we frequently meet in his arrangement with Labroid and Sciaenoid fishes stuck among the Percoids. The same errors exist, in greater or smaller numbers, in the works of his successors, because they attended more than they ought to have done to external characters, passing over the more essential conformities of internal structure. "Our (Cuvier's) precautions in separating fish whose teeth are supported by different parts of the mouth have saved us from much of this confusion, but yet there remained a considerable number of species which we could divide into groups only by employing subordinate characters. We characterized the primary divisions by the teeth, which in some are villiform and of even height, as in Perca and Labrax; sometimes interspersed with canines, or teeth a little higher and more pointed than the rest of the villiform band. Next we looked to the operculum, the edge of whose bony piece is sometimes smooth or rounded, sometimes terminated by two or three points more or less acute. Next we attended to the preoperculum, whose edges may be either smooth or denticulated, or armed in various ways with spines. Lastly, the bones of the jaws, smooth or scaly, furnish the final subdivisions; and to distinguish certain genera, we take characters from striking configurations of other parts of the fish." These are the rules which the greatest of ichthyologists, whether ancient or modern, framed for his guidance in the distribution of this portion of the finny tribes. Since his labours were brought to a close many new species have been discovered, and not a few new forms described; and we have therefore, as intimated above, relieved the overloaded Percoid group by removing some of the minor assemblages made by Cuvier himself, and placing them under distinct family appellations. It must be kept in mind, however, that the great mass of Acanthopteri, though exceedingly numerous in species, and presenting a great variety of generic forms, vary very little in the more essential parts of structure; and that the subdivisions which their numbers have made necessary are not of the same value in the animal scale as others containing perhaps only one or two species in other parts of the table.

The Serrani, called also Sea Perches, are numerous, still are called by the Roman fishermen by that of Perca, and by the Venetians by that of Sperga. The Anthias was more renowned in classical times. Aristotle says that the fishers of Sponges called it "sacred," because no voracious fishes came to the places which it frequented, and the diver might descend with safety. Pliny reports a singular story regarding it: The fishermen of the Chelidonian Isles, he says, practise the feeding of this fish, always presenting themselves in the same dress until its apprehensions are lulled, and then they introduce a hook into the paste they had daily given it. As soon, however, as an Anthias was deceived so as to allow itself to be hooked, its companions came to its aid, and endeavoured to relieve it by cutting the line with their dorsal spines, shaped like a saw.

"Anthias his tergo qua non vidit ultimae armis. Vim spinis novoque suo verso suplant. Corpores lina secat fixamque intercipit hamum."

Or., Halict., 46.

The modern Greeks give the name of Anthias to the Gymnetrus; and it is probable that the Anthias of Ælian was the Scouberoid alatonga of the modern Italians.

**Family II.—PERCIDÆ.**

**Genus Perca**, Artedi and Linn. Body oblong, scaly; scales ctenoid; opercular bones variously armed. Seven branchiostegals. Teeth on the vomer, and most frequently on the palatines. No barbels; cheek not cuirassed. Ventrales of five jointed rays, thoracic or subbrachial. Fins always amounting to seven in number, often to eight. Stomach cecal, that is, the pyloric opening lateral; pancreatic caeca few in number and not bulky; intestinal canal little folded.

(a.) Two dorsals, or one dorsal with a notch extending to its base; all the teeth villiform; no canine teeth.

**Genus I. PERCA**, Cuv. Preoperculum denticulated; operculum spiniferous; suboperculum feebly denticulated. Tongue smooth. Fourteen species.

**Genus II. Lates**, Cuv. Suborbital and corseid strongly denticulated; coarse denticulations at the angle and lower border of the preoperculum. Three species.

**Genus III. Cnidon**, Mull. and Trosch. Agrees with Lates in the almost total want of pseudobranchiae, but is distinguished therefrom by the entirely smooth under border of the preoperculum, whose hinder border is toothed and sends out a spine beneath. Nostrils remote from each other. Scalpula with only one spine and the suborbital scale bone nearly smooth.

**Genus IV. Psammoperca**, Rich. Body a handsome and regular ellipse, the rather small head forming the acute anterior end of the curve. Ctenoid scales rather large. Dorsal notched nearly to the base, moving in a scaly sheath. Teeth on the jaws; vomer and palatine bones crowded, rounded, granular; tongue smooth; cheeks and gill-covers scaly; preorbital entire on its edge, smooth; angle of the operculum running horizontally into a short strong spine, above which the edge of the bone is set with teeth like a comb; under limb of the bone smooth; a small spine on the operculum. Differs from Perca in the form of the teeth and by the absence of a well-marked preopercular disk; from Percalabrax by its smooth tongue and solitary opercular spine; and from Lates by the absence of angular teeth on the lower limb of the preoperculum, and by the perfectly entire preorbital. This genus might enter the group having a single dorsal. One species, Australia.

**Genus V. Labrax**, Cuv. (Percalabrax, Schlegel.) Suborbital and corseid not denticulated; two opercular spinous points. A disk of villiform teeth on the tongue. Eight species.

**Genus VI. Centropomus**, Linn. Operculum without spinous points. Dorsals separated by a small anal interval. Preoperculum denticulated on its posterior border, with some teeth in the raised anterior edge of its disk. One species.

**Genus VII. Enoplosus**, Cuv. Suborbital denticulated. Preoperculum denticulated and armed by a strong spine; operculum and corseid without spines. Body and vertical fins greatly elevated.

**Genus VIII. Diploprion**, Kuhl and Van Hass. Trispinous operculum; operculum obtuse at the angle, with a denticulated preorbital; preorbital spine three species.

**Genus IX. Grammistes**, Bloch. Scales minute, enveloped in mucoid epidermis. Dorsals near each other. Spinous preoperculum and operculum; no apparent anal spines. Two species.

**Genus X. Aspro**, Cuv. Body elongated. Dorsals at a little distance from each other. Snout thick, smooth, and projecting beyond the mouth. Two species.

**Genus XI. Ambassis**, Commer. (Chondos, Hamilt. Burch.) Both the anterior and the posterior edges of the preopercular limb denticulated; a recumbent spine pointing forward in front of the dorsal; operculum ending in a point; distinguished from Apogon by the contiguous dorsals, and the recumbent spine before the dorsal fin. No pancreatic caeca, in which the genus departs from the ordinary Percoid structure. Fourteen species.

**Genus XII. Propus**, Kuhl and Van Hass. Frontal border of the orbit continuous in other respects like Ambassis. One species.

**Genus XIII. Micropogonius**, Rupp. General aspect and the form and position of the fins as in Propus. Frontal border of the preoperculum not denticulated; an acute ridge extending from the eye dorsal above the scaly operculum. Lateral line commencing under the first rays of the second dorsal; only two stiff rays in the anal. Mandible projecting a little beyond the upper jaw; orifice of the mouth moderately large, armed by a row of wholly fine teeth; no teeth visible on the palate. Gill-openings large; branchiostegals seven. Large scales on the body, easily detached. One species, Sicily.

**Genus XIV. Bogoda**, Bleek. Separated from Ambassis by their entire preorbital scale-bones and conical jaw-teeth, which are bigger on the fore part of the mandible. Dorsals two, united at the base, continuous thoracic. Teeth on the jaws, vomer, and palatines. A recumbent spine before the dorsal. Branchiostegals six. Anal spines three. Pseudobranchiae. Six species. Bengal.

**Genus XV. Niphon**, Cuv. Strong curved spine at the angle of the preoperculum; fine denticulations on the vertical limb, and coarse teeth on the horizontal edge of that bone. The strong, sharp opercular spines; serrated preorbital. Long subelliptical body. Dorsals connected at the base; three anal spines.

**Genus XVI. Potamotus**, Risso. Somewhat of the aspect of Mugil. Eye very large. Two short dorsals near the middle of the back, separated from each other; anal posterior to the last one, also short; back a little keeled in front of the dorsal. Scales elliptical as in the rest of the family, covering the cheeks and gill-covers. Caecid deeply forked. Stomach cecal; twenty-two pancreatic caeca bearing each two groups; air-bladder very large, simple, with red elliptical granular bodies interiorly. One species.

**Genus XVII. Apogon**, Lacq. Scales large, readily deciduous. General aspect of Mullus. Dorsals two short, widely separated. Villiform teeth. A double preopercular border finely denticulated. Pancreatic caeca few.

(b.) Two dorsals, or one dorsal deeply notched. Long canine teeth accompanying the villiform bands on the jaws.

**Genus XVIII. Chelomysticus**, Lacq. Have the characters of Apogon, with the addition of long pointed more or less curved teeth on the jaws, along with the fine villiform bands, which exist also on the vomer and palatines. Preoperculum with a finely den- Classification—Acanthopercoides Fishes.

Genus XXI. Serranoides, Cuv. Preoperculum rounded at the angle, denticulated on the horizontal portion of the curve, as well as on the posterior edge; opercular spine, without spines. Large, readily deciduous scales, and the dorsal well separated. Stomach large, caecal; about three pancreatic ceca. Three species.

Genus XXII. Anthias, Bloch. Serranoides of small size, and generally brilliant colours. Head and jaws scaly, the maxillary being densely covered with conspicuous scales. Six species.

Genus XXIII. Merou, Cuv. Serranoides of larger size generally than Serranoides proper, or Anthias. Operculum with two, or mostly three, spines. Very small scales on the mandible. One hundred and forty species.

Genus XXIV. Plectroptera, Cuv. Serranoides on the lower border of the preoperculum turned obliquely forwards, and somewhat resembling the denticulations of a cock's comb. Upper border mostly entire. In other characters Serranoides. Operculum spinous. Sixteen species.

Genus XXV. Diacanthus, Cuv. Characterized by a rounded notch above the angle of the preoperculum which receives a small knob of the interoperculum. In other characters Serranoides. Forty species.

Genus XXVI. Mesopristes, Cuv. Serranoides in fins, teeth, and preopercular denticulations, but with an unarmed operculum, ending in a smooth point, not spinose, nor pungent. Nearly allied to Diacanthus, and many species have even the knob of the interoperculum and corresponding notch in the preoperculum, but not so distinctly formed. From Diacanthus, which they resemble in external form, they are distinguished by their vomerine teeth and denticulated preoperculum. Fifty-four species.

Genus XXVII. Arripis, Cuv. Canines on both jaws; short villiform teeth on the vomer and palatines. Operculum with two very small spinous points; but the preoperculum smooth-edged. It would be almost an Etheostoma if its dorsal were not single; or a Gyrinoides, if it wanted the canines. Air-bladder ample. One species.

(d.) A single dorsal, with villiform teeth only, and no canines.

Genus XXVIII. Agerina, Cuv. Whole head destitute of scales. Muciferous excavations in the bones of the cranium; five or six in the suborbital chain, and more on the limbs of the mandible; small spinous points with sinuses between, but no serratures on the border of the preoperculum. Two anal spines. Two species.

Genus XXIX. Pentaceros, Cuv. Body oval, high. Preorbitals, opercular pieces, cranium, and coracoid, coarsely striated. Cheek scaly. Blunt conical tubercles over the eye, and on the occiput. Scales of the body striated and granulated, and strongly adherent. Villiform teeth on the jaw and front of the vomer. Ventral wide apart, their spines very large; five anal spines. Caecal stomach; air-bladder large; large air-bladder. One species.

Genus XXX. Centropristes, Cuv. Analogous to the Serranoides in the union of characters derived from a spinous operculum, and a serrated preoperculum. Differs from Polyprion in the absence of a denticulated crest on the operculum, and the want of denticulations on the preopercular. The snout, jaws, and gill-membranes are destitute of scales, but the cranium, cheeks, and opercular pieces are scaly, the scales on the operculum being larger than those of the cheek. Fourteen species.

Bonnemaison divided this genus into three groups: Centropristes proper, having bigger conical teeth mixed with the granular ones on the jaw, and an internal band of vomerine teeth in a chevron. It comprehends C. atrarius, tabacarius, striatus, maculatus, and auratus. Hemodon (Arrigis, Jenyns) has card-like teeth on the jaws; an oblong, three-cornered group of vomerine teeth, and a more elongated body. C. tristis, georgianus (Australian fish). Myriodon, all the jaw-teeth equally minute; vomerine teeth in a chevron. C. scorpioides.

Genus XXXI. Aulacogaster, Schleg. Three spines on the operculum; preoperculum strongly serrated on its horizontal border. Caudal fin rounded. One species.

Genus XXXII. Glauconemus, Schleg., Rich. Aspect Sciuroid. Low spinous part of dorsal, peaked soft part. Head, except the lips and gill-membrane, densely scaly. Scales on the basal half of the soft-rayed vertical fin. Technically Centropristes, but having a very different general appearance. Card-like teeth on the jaws, vomer, and palate. Scales moderately large, ctenoid. Preoperculum circularly crenulated; two flat, bony points to the rounded operculum. Branchiostegals seven, occasionally eight. Two species.

Genus XXXIII. Gyrinoides, Cuv. Centropristes, with a smooth-edged preoperculum. Scales small, thin, embedded in the skin, extending over great part of the fins, and covering the gill-rays, throat, and all parts of the head, except the lips and the folds that shut up when closed. Notch between the dorsals equal to half their height.

Genus XXXIV. Apogon, Cuv. Belonging to the Percoids, with a single dorsal, but distinguished by the total absence of true spines or denticulations on the opercular bones, or those of the shoulder. Teeth very fine, bifid, in a narrow band on the jaws and palatines. Seven branchiostegals. Differs from Centropristes in the want of denticulations on the preoperculum, and from Gyrinoides in having no supracleural spine. Scales thin.

Genus XXXV. Rhytichthys, Cuv. No denticulations on the operculum or preoperculum, but short spines on both. Head smooth, without scales. Scales deeply imbedded in a mucilaginous skin. In other characters much like Serranoides. Few spines in the dorsal. Long caecal stomach, pointed at the end; six or seven pancreatic ceca; air-bladder oval, not large. Two species.

Genus XXXVI. Polyprion, Cuv. Preoperculum strongly and irregularly denticulated, and the anterior border of its limb rough. A strong spinous crest extends along the middle of the operculum longitudinally, and there is a less prominent point below it; the edges of the suborbital and interoperculum are finely denticulated. The preopercular is also slightly crenulated, and there are denticulated crests and tubercular eminences on the upper border of the orbit and top of the cranium, with serratures on the supracleurals and coracoid bones, giving the head some resemblance to that of a Scorpaena. Stomach caecal, obtuse; two pancreatic ceca. One species.

THERAPONIDAE.

The preceding family of Percoids contains the genus Perca, as sketched out by Artedi and Linnaeus. The numerous species discovered subsequent to the days of these naturalists, and accumulated in the rich Parisian museum, brought to the knowledge of Cuvier many new Percoid forms which departed more or less from the typical Perca of the older ichthyologists. In the Histoire des Poissons these are mostly introduced as appendages to the normal Percoids, and contain fishes with fewer branchiostegals than seven, or with more soft ventral rays than five, or with some other striking external peculiarity by which they can be distinguished as minor groups, but which differ little from the true Percoids in essential internal structure. We have separated one large group of these Percoid allies as they may be called, to form the family of Therapontidae, distinguished from the more typical Percoids by the characters indicated in the table. But in the family thus brought together, there are several minor groups very natural in themselves, but which do not retain a general family likeness, extending to all the groups. The first three genera are distinguished from the others by the lower rays of their pectorals being simple, and formed evidently as organs of touch, and the next three genera are American fresh-water fish, of much beauty and neatness of aspect. These are followed by five or six genera, with generally well-armed opercular bones; then there are several newly proposed genera, in which a family aspect is less recognisable; and, lastly, we have placed at the end of the family Macquaria and Latilus, two genera associated by Cuvier with the Sciaenoids, but which, notwithstanding the absence of teeth on the palate in the one, and the wholly toothless mouth of the Family III.—Therapontidae.

Thoracic scaly fishes. Branchiostegals six. Two dorsals, or the spinous and soft dorsals united to form one fin. Scales ctenoid or cycloid. Teeth on the jaws, and mostly generally on the palatines and vomer. Opercular pieces variously denticulated or spinous, or some of them unarmed. Five soft rays in the caudal, with one spine; lower pectoral rays in some genera unbranched, pointed, and prolonged beyond the membrane, but in most of the ordinary forms not. A rather heterogeneous assemblage of Percoids, brought together by the single character of six branchiostegals, but differing in some having cycloid, others ctenoid scales, and even in the same genus in the presence or absence of teeth on the palate, the teeth of that part falling out when the fish is still young.

Genus I. Ctenichthys, Cuv. Resemble Mesopristis in their scales, fins, and in having a denticulated preoperculum, and the operculum ending in a flat, smooth corner, but are distinguished by the lower pectoral rays being thickened, simple, strongly jointed, and elongated beyond the membrane, seemingly to serve as organs of touch, such as exist in many of the Salmonidae. The vomer is armed with villiform teeth, but there are none on the palatines. Stomach rather short; pancreatic caeca four; no air-bladder. Eight species.

Genus II. Aploactites, Cuv. Lower pectoral rays thick, fleshy, jointed, but not branched, and protruding beyond the narrow membrane at the tips. Teeth thin narrow plates lobed at the crown, in many rows on the jaws, the outer row taller than the interior ones, the newest of which are very short, and to the naked eye radiform. General aspect of Grypus. Scales small, striated on the edges, covering most of the head and fins. Interoperculum scaleless; preoperculum smooth-edged. A small, flat, smooth opercular spine. Branchiostegals six. Ventrales posterior to the pectorals, in consequence of the elongation of the public bones, which are attached to the coracoidei. Mouth small, excal, with an ascending pyloric branch exceeding its size; two short pancreatic caeca; a large, simple air-bladder. Three species. Distinguished from Ctenichthys by its teeth, like those of Ctenidium.

Genus III. Chironemus, Cuv. Differs from the Salmonoid Chirostoma in having vomerine teeth on the fore-part of the bone; teeth generally setiform, few and feeble. Scales cycloid; opercular pieces and cheeks covered with scales, not greatly smaller than those of the body. Preorbital high, like that of a Sparoid. Preoperculum smooth-edged, rounded at the angle; operculum with two flat points, scarcely pungent. Caecal stomach, pretty large; four short pancreatic caeca. One species.

Genus IV. Centrarchus, Cuv. (Ichthyella, Rafin.) Oral, compressed body. A single dorsal. Villiform teeth on the jaws and front of the vomer; on the palatines in two patches, and on the base of the tongue; no canines. Preoperculum generally entire; angle of the operculum divided into two flat points. Anal spines from three to nine. Scales ctenoid. Nine species.

Genus V. Pomotis, Cuv. A rounded, skinny, coloured fish prolonging the operculum, whose bone ends in an obtuse angle. Pharyngeal teeth cylindrical, with flat tops, disposed in a pavement-like manner; villiform teeth on the jaws, and a row across the front of the vomer, but none on the tongue. Three anal spines. Stomach caecal, obtuse; pancreatic caeca six. Ten species.

Genus VI. Brytes, Cuv. Pomotes with a narrow band of villiform teeth on the tongue; three dorsal spines. One species.

Genus VII. Ponticola, Guichen. Body depressed, oval, high, covered with eliatised scales. Snout short and conical, but frame a moderate-sized mouth; teeth on the jaws crowded, coarse, acute, the exterior ones somewhat curved. Preoperculum, interoperculum, suboperculum serrulated at the corners. Tongue smooth. Operculum spinous, without a membranous border. Dorsal single; ventrales thoracic. Branchiostegals six. Fresh water, Aleppo. Near Catrorhynchus, Pomotes, and Brytes.

Genus VIII. Pseudanthus, Cuv. Angle of the preoperculum projecting in form of a flat spine, which is denticulated or crenulated on the edges like the rest of the bone; resembling Anthias in the whole mouth and jaws being covered with strongly ctenoid scales, which extend along the median line of the throat. No canines; mouth narrow; teeth villiform; teeth on the jaws, the chevron of the vomer, and along the palatines. Movable projecting at the chin. Eyes large. Six branchiostegals. Posterior end of the tril a vertical slit; anterior one a small round hole. Form oval; the dorsal and anal rounded. Stomach large, caecal, rounded posteriorly; five thick pancreatic caeca; air-bladder of moderate size, rounded anteriorly, pointed behind. Eighteen species.

Genus IX. Dulcis, Cuv. Centropomis by external form and interior structure, but their six branchiostegals have caused us to place them in a separate group. Some have a single dorsal, and three opercular spines; others a notched dorsal, and only two spines on the operculum. Vestiges of serratures on the suborbital, and some very fine and little apparent ones on the preoperculum. Teeth coarsely villiform on the jaws, chevron of the vomer, palatines, and tongue. Twelve species.

Genus X. Therapon, Cuv. Villiform teeth on the jaws; denticulated preorbital; preoperculum, and often the supramaxillary or coronoid, also denticulated. Six branchiostegals. No scales on the cranium, snout, or jaws. Spinous part of the dorsal folding back into a scaly furrow. Air-bladder always divided into two distinct sacs by a contraction as in the Cyprinids, the Characidii, and Mygobius. The palatine teeth are in some deciduous at a young age; they have the outer row of jaw-teeth stronger than the others. Stomach caecal; about twelve pancreatic caeca; anterior division of the air-bladder globular. Twelve species.

Genus XI. Datnia, Cuv., are a group of fishes closely related to Therapon, and differ in having a more elevated body, a straight or concave profile, a pointed snout, and by the dorsal spines being stouter, and occupying a greater length of the back, though not more numerous. The dorsal is slightly notched, and they have no teeth on the palate. Stomach caecal, rounded behind. Three species.

Genus XII. Palates, Cuv., is a third division of Therapon, and is distinguished by a more even dorsal, less notched, and by the opercular spine ending in two feeble points, scarcely to be felt through the integument. Snout somewhat obtuse; mouth small; jaws equal; teeth villiform in three or four rows, but none on the vomer or palatines. Three species.

Genus XIII. Helotes, Cuv. A fourth division of Therapon, having like the first one a deeply-notched dorsal, and an opercular spine. Body oblong. Head small; mouth narrow, as in the third division; exterior row of teeth minutely tricuspid; no palatine teeth. Two species.

Genus XIV. Datnoides, Bleek. Distinguished from Therapon, Datnia, Palates, and Helotes, by the suborbital scale bone not being notched, and by a simple swim-bladder. Dorsal fin simple. Premaxillary and mandibular teeth simple, pluriseriatus; no canines. Vomer and palatines smooth. Preoperculum denticulated, without larger spines; suborbital edentulous. Branchiostegals six; lips membranous, entire, not similitated. Head small; mouth scaleless. Genus XV. Barbus, Bleek. Separated from Nandus by the entire preoperculum and toothless tongue. Dorsal fin single, smooth on the jaws, palatines, and entopterygoids; tongue smooth; suborbital scale bones and preoperculum not toothed. A single opercular spine. Branchiostegals six. Lateral line interrupted; upper jaw protractible; inferior pharyngeals oblong, contiguous, but not united. Genus XVI. Nandus, Cuv. Mouth protractible; teeth villiform, very close and short on the jaws, palatines, and chevron of the vomer. Preoperculum and interoperculum finely denticulated on the edge; opercular spine so small as to be easily overlooked. Body small, cyprinoid. Intestines resembling those of a Labrid; stomach siphonous with a very short ascending branch; no pancreatic caeca; air-bladder simple. One species.

Genus XVII. Catopria, Bleek. Dorsal solitary. Sebacous teeth on the jaws, palatines, and vomer; pterygoid and lingual teeth granular, in an oblong patch. Preorbital scale bone and preoperculum denticulated; two flat spines on the operculum. Branchiostegals six. Lateral line interrupted; upper jaw protractible. Bleeker makes a family group of this genus and Nandus, and indeed the position of Nandus, with its aliphalon stomach, and want of pancreatic caeca, does not seem to be with Therapon.

Genus XVIII. Anoplus, Schleg. Distinguished from Datnia by having vomerine teeth; from Nandus by the want of palatine teeth. Breeds in all the three species, A. barbus.

Genus XIX. Bolcomystax, DeKay. Two dorsals. Smooth-edged preoperculum; operculum scaly, with a spine. Branchiostegals six. Nape narrow, compressed. Rivers, New York.

Genus XX. Pilloma, DeKay. Two separated dorsals. Smooth preoperculum. A flat, weak, opercular spine. Ventrales with five soft rays. Teeth of equal size. Lake Champlain.

Genus XXI. Leptosoma, DeKay. Body and fins scaly. Fleshy appendages along the lower edge of the head and round the eyes. One dorsal. Branchiostegals six. Teeth on the jaws, vomer, and palatines. Ventrales before the pectorals. One species. Florida.

Not having access at present to the works in which Dr DeKay has described these three fresh-water genera, we merely give the genera as they are quoted in the Archiv für Naturgeschichte for 1844; and cannot therefore, without more data, fix their proper place in the system. Along with these genera, ranged in the family of Therapontidae, we place part of the Salmonoids, "with fewer than six branchiostegals," described in the Histoire des Poissons. Their abstraction from the Salmonoids renders the characters of that group more precise, and they are separated from the Therapontidae. more by the toothless palate than any difference of form or general structure.

**Genus XXII. Lophotes, Cuv.** Branchiostegals six. A single dorsal; thoracic ventrals with five soft rays. Body, opercular pieces, and cheeks scaly. Snout short; prominent mandible; profile of face somewhat concave. Very coarse denticulations on the preoperculum. Soft portions of the anal and dorsal prolonged in such a manner that posteriorly the fish appears to be trilobate, the rounded caudal forming the middle and longest lobe; entire form oval and thickish. Spines of the fins strong, and those of the back reclining in a scaly furrow when at rest. Four pores, or four groups of minute pores towards the end of the mandible. Scales ciliated. Lateral line continuous. Stomach excaul, very large, and fleshy; three pancreatic ceca; large oblong air-bladder. Four species.

**Genus XXIII. Scopelides, Cuv.** Connected with the Scin- noids, and especially with Pristigaster and Diapogon by the den- ticle-like teeth of the preoperculum, but these are either not present on the end of the mandible or only very minute ones, easily overlooked. The peculiar generic character consists in the second suborbital scale bone ending in a spinous point, close under the orbit, pointing backwards; and the third bone of the chain frequently sends out one in the opposite direction which meets it. Body oval or oblong. Dorsal continuous in outline. Eye large. Mouth moderate. Scales pretty large, extending to the occiput, opercular pieces, cheeks, and throat. Dorsal spines reclining on a scaly furrow, and having their broader sides turned alternately to the right and left, as in many Scinnoids and Sparoides. Caudal notched or forked. Stomach excaul, rounded, very small; pancreatic ceca six thick, as long as the stomach; air-bladder simple. Twenty-two species.

**Genus XXIV. Haemulon, Cuv.** Small fishes. Dorsal solitary. Branchiostegals five. Rays of the pectoral entire. Suborbital scale bones smooth, without spines. Preoperculum denticulated; a solitary opercular spine. Premaxillary teeth bristle-shaped, pluriserial, with four canines anteriorly; mandibular teeth also pluriserial and bristle-shaped, with two canines, and a row of conical teeth behind. Batavia.

**Genus XXV. Macquaria, Cuv.** General form Percoid, with the muciferous excavations of the bones of Acetaria. No teeth. Branchiostegals five. A pit and two small pores beneath the end of the mandible as in many Scinnoids. Preoperculum, subpercu- lum and interoperculum, suprascapular and coracoideally denticulated or serrated; operculum terminated in two thin, flat, bony points, separated by a cleft. Stomach excaul; eight pancreatic ceca; air-bladder either absent or very small. One species.

**Genus XXVI. Latilus, Cuv.** Forms in the division of Scin- noids, with an undivided dorsal, as given in the Histoire des Poissons, a genus remarkable for its arched profile descending almost vertically, the very short snout and large eye, near the profile. Horizontal mouth reaching the front of the eye, and a general form of the tapering body, resembling Cyprinidae. Teeth, a cross band in front of the vomer, none on the palatines; four or five larger curved teeth in front of the villiform band on the jaws. Branchiostegals six. Preoperculum very finely denticulated; operculum ending in a single point. Suprascapular smooth. Dorsal rays slender, flexible. Scales minutely ciliated. Lateral line straight, continuous. Stomach excaul; one pancreatic cecum only observed; air-bladder simple, large. One species.

**Poly nemids.**

This small family has relations with the first group of the Theraponidae, in the existence of long feeler-like rays in the pectorals. In one species of Poly nemus, the long free pectoral rays have obtained for it the appellation of Paradise-fish, from the resemblance these filamentous rays bear to the tail-feathers of a bird of Paradise. Poly nemus is also remarkable as being a genus, otherwise natural, of which the species exhibit great varieties in the form of the air-bladder. In some, that viscus is lobed posteriorly, and fringed on the sides with many pointed processes; in other species, the air-bladder, though large, is quite simple, and in others there is no air-bladder at all, just as it is wanting in some species of Scom- ber. The Poly nemus indicus, which has a large air-bladder with from twenty-eight to thirty-five of these lateral appendages springing from it, and also a very great number of pan- creatic ceca divided into two bundles, furnishes most of the isinglass that is procured at Penang. The weight of this fish is commonly from 4 to 6 lbs., and seldom exceeds 20 lb. The air-vessel of a good-sized fish when dried and ready for the market weighs upwards of two ounces, and the isinglass is considered to be very good, and fetches from 25 to 30 Spanish dollars the pikul. The prepared air-vessels are known in eastern commerce by the name of "Fish-maws," and in 1842 between 12,000 and 13,000 dollars worth were exported from Prince of Wales Island (Singapore). They are not obtained exclusively from the Poly nemus, though its isinglass is among the best. Dr Cantor, from whom these particulars are quoted, says that the fishery is carried on in a very rude manner, chiefly by the Chinese, and might be almost indefinitely extended by European capital and skill.

**Family IV.—Polynemide.**

Acanthopterygians with abdominal ventrals, a position resulting from the elongation of the public bones which are suspended to the coracoids. Teeth on the jaws, front of the vomer, and palatines. Two dorsals; scaly appendages in the axilla of the pectorals and ventrals. Scales ctenoid, feebly ciliated. Pancreatic ceca.

**Genus I. Polynemus, Lian.** Body oblong. Head covered, even to the branchiostegal membrane, with deciduous scales. Preoperculum denticulated. Villiform teeth on the two jaws, front of the vomer, and on the palatines; tongue short and broad, smooth. Wide gill-openings; seven branchiostegals. The two openings of each nostril near to one another and near the end of the snout. Dorsals widely separated, the second one being distant also from the caudal, and corresponding in position with the anal; caudal forked, generally unequal. Small scales on the three vertical fins, and on the base of the pectoral; a number (varying with the species) of the under pectoral rays free, long, and filiform, separated from the fin by a fairly space. Pancreatic ceca two, four or three; stomach obtusely cecal; one pancreatic ceca (six or more); air-bladder large, pointed, and entering among the muscles of the tail; in some species the air-bladder is wanting, in others that viscus has many (from twenty to thirty) processes on the ventral surface. Sixteen species.

With this we associate a Scinmoid genus, which has had no other more appropriate place assigned to it as yet, and which has many characters in common with Polynemus.

**Genus II. Cheilodactylus, Lacep.** Scinnoids with an oval compressed body; small mouth; villiform teeth, or conical, scarcely acute, on the jaws only, and not on the palate. Preorbital and preopercula without denticulations; opercular and suprascapular vertebrae attached only to the inside of the pectorals, but with the public bones suspended from the coracoid. Branchiostegals six, more rarely five only. Stomach excaul; pancreatic ceca two, short; rectum dilated, muscular. The lower pectoral rays, to the number of six or seven, are simple, and one of them commonly thicker than the rest, is elongated into a filiform tip, which often reaches the end of the anal. Caudal forked. Many have a slight prominence before the orbit, and in one or two species it rises in a conical form. Eight species.

**Genus III. Latris, Rich.** A division of Cheilodactylus, with generally more-elongated elliptical bodies, and none of the simple rays of the pectoral passing the membrane. The ascending limb of the preoperculum is minutely serrated in some, and smooth in others. Three Australian species.

**Surmullet Family.**

The fishes of this family were denominated πράγλα by the Greeks, and mullus by the Romans. The Greek name is said to have originated in the three spawning seasons attri- buted to the Surmullets, and they were dedicated to the tergeminos or tricipitous goddess Hecate. The Latin name had another origin according to Pliny—a colore mul- leorum calceamentorum, from the red-coloured shoes or buskins worn by the kings of Alba, and afterwards by the consuls, praetors, and curule ediles. By the luxurious Romans, the Surmullets were held in such repute that they sought for them far and wide, and without regard to expense. They seldom exceeded 2 lb. in weight, and the purchase of a large one, the price augmenting in a greater ratio than the size, was considered to be an act of magnificence. A Surmullet of 3 lb. weight was an object of admiration, and one of 4 lb. entailed ruin on the purchaser. Seneca relates the history of a Surmullet that was presented to Tiberius, and which that emperor, in a fit of economy, sent to the market. Apicius and Octavius were competitors for it, and the latter became the purchaser at the cost of 5000 sesterces, or upwards of L.40 sterling. Asinius Celer paid 8000 sesterces for one in the reign of Caligula. The high-priced fish were brought from a distance, as they did not thrive in ponds, and increased little there in weight, though extraordinary pains and expenditure were employed in the endeavour to rear them. It was one of the luxuries of a giver of feasts to cause these fishes to swim down streams led through the banqueting room, that his guests might enjoy the sight of their brilliant colours during their repast, or to let them die in glass vessels, that all the varying hues of the expiring fish might glint their eyes. Seneca says the fish swim under the very couches of the guests, and they are caught under the table that they may be the sooner placed upon it, no Surmullet was considered to be fresh unless it expired in the hands of the guests. They were exposed in vessels of glass, that the different colours they assume during a slow and painful agony may be noticed. Nothing was considered to be more beautiful than a dying Mullet. The struggles of the fish to escape death bring out the most brilliant scarlet tints, which are followed by a general paleness; and in the passage from life to death these two extreme tints mingle, says the author from whom we borrow, in the most agreeable manner. The liver of the Surmullet was considered to be the most delicious part, and was bruised in wine to make a garum for the flesh. Even in the present day the Surmullet is considered to be one of the best of sea-fishes—its flesh being white, firm, tender, of an agreeable flavour, and easily digested because it contains little fat. The scales of the Surmullets are strongly ciliated.

**Family V.—MULLIDÆ.**

*Les Mullus, Cuv.* A perfectly natural family, distantly allied to the Percoids, but readily distinguishable from other Acantopterygii by the two dorsal widely separated from one another, by the large and easily-detached scales of the head and body, and by the pair of external bars of the mandible which retire between the limbs of that bone when not in use. Body oblong, little compressed. Fins of moderate spread. Profile more or less convex above and below. A high narrow preorbital; small mouth, with feeble teeth. Gill-opening wide; four branchiostegals. Mucoiducts forming the lateral line divided into a cluster of branches on each scale. Siphonal stomach; numerous pancreatic ceca.

**Genus I. Mullus, Linn.** No teeth on the upper jaw; a disk of pavement-like teeth on the front of the vomer. No spine on the operculum. No air-bladder. Two species.

**Genus II. Upeneus, Cuv.** Short teeth on both jaws, sometimes closely villiform (Upeneoides, Bleek.) sometimes distinct and unserial (Upeneus, Bleek.) Some have villiform teeth on the palate or vomer; in most these bones are destitute of teeth. Thirty-eight species.

**Genus III. Acropoma, Schleg.** General aspect of Mullus, but distinguished by the want of barbels. Anal nigh the ventrals, at a wide distance from the anal fin. Jaw-teeth pointed, the foremost being canines. Branchiostegals seven.

**HOLOCENTRIDÆ.**

This small family consists of that division of Cuvier's Percoids whose members have more than seven branchiostegals, and whose soft ventral rays exceed five. The group is a natural one, all the species having a common likeness which is very recognisable. They are the only Acantopterygi which have this unusual number of rays in the ventrals, and are fishes remarkable for the brilliancy of their colours, the neatness of their forms, and their very ctenoid scales. They are not the objects of any special fishery.

**Family VI.—HOLOCENTRIDÆ.**

*Holocentridæ, Bonap.* Acanthopterygians, with more than five branching rays in the ventrals, and seven branchiostegals. A natural group, recognizable by the large, very strongly toothed or serrated scales, the furrows and streaks on the sides of the cranium, face, and gill-cover, the serratures on the edges of the opercular pieces, and the general stoutness of the spines of the fins. Cheeks scaly. Dorsals single, or deeply notched, or two contiguous dorsals. Small spines above and below the caudal; dorsal spines falling back into a furrow. Otolites large. Air-bladder connected with the otocrane by an osicle and a tympanum closing the orifice; stomach caecal; numerous pancreatic ceca (eight to twenty or more).

**Genus I. Myripristis, Cuv.** Somewhat of the aspect of Apogon. Cranium sculptured. Dorsals two, contiguous, or one deeply notched. Preoperculum with its border serrated, and also a serrated line in front of the limb, but no spine at its angle, by which it is distinguished from Holocentrus. Villiform teeth on the jaws and front of the vomer, with a few big ones coming from the jaws of a short obtuse conical form. Tongue smooth. An acute opercular spine. Stomach caecal, reaching the middle of the cavity of the abdomen; nine pancreatic ceca; fibrous exterior coat of the air-bladder, which is large, and divided into two by a contraction. Fourteen species.

**Genus II. Holocentrum, Cuv.** *Myripristis* with a strong spine at the angle of the preoperculum. Dorsal slightly notched. Third anal spines generally very large. Otocrane not always connected with the air-bladder, which is simple and extends the whole length of the belly, and is not forked anteriorly. Stomach caecal; eight pancreatic ceca. Twenty species.

**Genus III. Pterois, Cuv.** Holocentrus with a very large eye, but differing in having a single dorsal, with only slender spinous rays in front, and without any notch of separation. Anal spine not remarkable for size. Stomach caecal, cylindrical, obtuse; ascending branch fleshy. Long, slender, numerous pancreatic ceca; air-bladder wide, and running the whole length of the abdomen. Four species.

**Genus IV. Rhynchichthys, Cuv.** General habit of Holocentrus, but with the cranial crests prolonged anteriorly into an acute snout, somewhat resembling that of Macrouros. A projecting spine at the angle of the preoperculum; strong denticulations on its borders, and also round the posterior edge of the operculum, but no strong spine in the latter. Two species.

**MAILED CHEEKS.**

The three Liancan genera, Trigla, Cottus, and Scorpaena, are the foundations of this numerous family, so remarkable for the variety of forms it offers; for the beauty of some, from the splendour of their colours, the elegant arrangement of their tints, or the gracefulness of their fins; and for the ugliness of others of disagreeable shapes, and having loose disgusting skins. Few fishes are so handsome, or more delicate in appearance than *Pterois*, whose fins resemble the long feathers of the gayest birds, while *Pelor* and *Synanceia* are about as ugly as a fish can be. The following table of the genera is taken from the *Histoire des Poissons*. The Trigle or Gurnards are too well known to need a description; at the same time they convey a good idea of the general form of one of the leading tribes of the family, and one in which the characteristic development of the second suborbital scale bone is well seen. This bone in all the Selengonoids either covers the whole cheek, or sends a process across it to the curve of the preoperculum opposite to the spine at the angle, to which it serves as a point of resistance when the spine is used as a weapon. This elongation of the suborbital is often crested by an acute ridge, and most commonly armed with spinous points. The air-bladders of the Gurnards are variously lobed, and some of the species have been noticed to emit a grunting noise when caught, which some observers have supposed was produced by that organ; but it is the character of the order to have no air-duct to the swim-bladder. The flesh of the Gurnard is very white, firm, and wholesome.

The common Dactylopterus or Flying-fish of the Mediterranean (Trigla volitans, Linn.), is a species too remarkable for its functions, so opposite to those of its class in general, not to have attracted from an early period the attention of mankind. It is extremely common, and has been mentioned by all the authors who have treated of the fishes of that inland sea. The ardour with which it is pursued by the Dolphins and Bonitos, the sudden effort which it makes to escape these predaceous creatures by vaulting into the air, the new and probably unthought of dangers which there await it from gulls and other aquatic birds, render it an object of the highest interest to the unaccustomed landsman, somewhat wearied with the monotony of a sailor's life. "It is by the extension of the pectoral rays and membrane that the fish is enabled to raise itself from its proper element to the regions of the air, though this is by no means a continual flight, for the utmost it can do is to describe an arc over the surface of the water extending to a distance of about 120 feet, and sufficiently elevated for the fish sometimes to fall on the deck of a large vessel. This power of flight or momentary suspension would be much greater if the pectoral membrane could preserve its humidity longer, but it is soon evaporated in the heat of the tropics; and the membrane, as it becomes dry, loses its buoyant power, and the fish falls. They are sometimes so numerous as to afford much pleasure to the spectator by their repeated flights; and at particular times, especially on the approach of rough weather, in the night, numbers of them may be seen, by the phosphoric light they emit, marking their arched passages in apparent streams of fire." Such is the current account of the flights of this interesting fish, and of the causes of it; but it is probable, as has already been observed of the Exoceti, that the Flying-fishes do not soar into the air merely when pursued by their enemies, for this would only be incidente in Syllam cupiens ritare Charpydim, but also to subserve some purpose in their economy.

The Cotti are characteristic members of another group of the Mailed Cheeks. The fresh-water species of this genus have the head almost smooth, and only a single spine to the preopercle. Their first dorsal is very low. The most common is the river Bull-head (Cottus gobio, Linn.), sometimes called the Miller's Thumb. It is a small dark-coloured fish, 4 or 5 inches in length, and frequent in most of the streams of Europe and the north of Asia. It usually lies concealed beneath stones, from whence it darts with great rapidity upon its prey. It is said to be extremely prolific; and the female, when with spawn, becomes so greatly enlarged, that her ovaries protrude like mammae. The Bull-head, like the Salmon, has a reddish hue when boiled. It affords a good and wholesome food, much sought after by the mountain tribes of several countries.

The Scorpaena are found in all seas in considerable numbers, and present a great variety of aspects, some being nearly as ugly as a Pelor, while others passing, as it were, into the nearly allied genus Sebastes, have a Percoid neatness of appearance. The species here figured is an Australian one, Scorpaena Stokesii.

The Platyccephali may be considered as elongated and form of one, which, however, is not so flatly depressed as many others of the genus. They are common ground-fish in the southern hemisphere. Fig. 42 gives a view of a scale from the lateral line of the same species. *Synanceia horrida*, as the title implies, exhibits by no means an inviting aspect. It is named *Ikan-swampi*, or Sorcerer-fish, by the Malays. *S. brachio* of Cuv. is the species called *Fi-fi*, or *Hideous*, by the Negroes of the Isle of France, who hold it in great abhorrence. In fact, nothing can be conceived more frightful. At first sight no one would consider it a fish, but rather as a mass or unformed lump of corrupted jelly. "Totum corpus," says Commerson, "muco squamidum et quasi ulcerosum." Its head and members seem enveloped in a sack of thick, soft, spongy skin, warty and wrinkled like that of a leper, and irregularly blotched over with various tints of brown and gray. Sometimes it appears entirely black; but it is always gluey and disgusting to the touch. The little eyes are scarcely discernible in the large cavernous head. This species is said to possess great tenacity of life, and survives for a long time out of the water. The skin, in fact, forms a little ring like that of *Pelot* above the point of the operculum, through which the fish can respire at pleasure, leaving the remainder of the gill-opening closed, and the gills consequently little exposed to exsiccation. The inhabitants of the Isle of France regard this fish as a reptile, and dread its sting, meaning the wounds inflicted by its spines, more than that of snakes or scorpions.

The genus *Apistes* was so named by Cuvier from the treacherous way in which these fishes conceal the moveable preorbital spine, by laying it along the cheek, and on any one attempting to seize them, raising it suddenly so as to inflict a disagreeable wound. The Greek word from whence the name was derived signifies "perfidious." Since Cuvier's time several species have been discovered possessing this suborbital weapon, but varying considerably in the rest of their form from *Apistes*, as described by him. One of these new forms is *Choridactylus multibarbus*, of which a figure (fig. 9) has been given. Some of these *Apistes*, having large pectorals, are able to sustain themselves in the air for a time, as Flying-fishes. One of the remarkable forms of the family is represented by fig. 14. It is the *Monocentris Japonica*.

The *Gasterostei* differ from the rest of the family in having the spines of the dorsal free and detached. The species are small fishes familiarly known under the name of Sticklebacks (Scotice, *Benticle*), and extremely common in all the fresh waters of Europe. Gesner indeed asserted that they did not occur in Switzerland; but the contrary has been long since ascertained. Our most common species is *G. aculeatus* (Linn.), under which name, however, it is supposed that more than a single kind has been confounded. It is an active and greedy little fish, extremely destructive of the fry of other species, and consequently injurious in ponds where these are sought to be preserved. Mr Henry Baker informs us that it will spring not less than a foot perpendicularly out of the water and to a much greater distance in an oblique direction, when it desires to overcome any opposing obstacle. "It is scarcely to be conceived," he adds, "what damage these little fish do, and how greatly detrimental they are to the increase of all the fish in general among which they live; for it is with the utmost industry, sagacity, and greediness that they seek out and destroy all the young fry that come in their way, which are pursued with the utmost eagerness, and swallowed down without distinction, provided they are not too large; and in proof of this, I must assert that a banquet which I kept for some time, did, on the 4th of May, devour, in five hours' time, seventy-four young dace, which were about a quarter of an inch long, and of the thickness of a horse's hair. Two days after it swallowed sixty-two; and would, I am persuaded, have eat as many every day, could I have procured them for it." The Stickleback sometimes swarms in prodigious numbers. Pennant states that at Spalding, in Lincolnshire, there are once in seven years amazing shoals, which appear in the Welland, coming up the river in the form of a vast column. This concourse is supposed to arise from the multitudes which have been washed out of the fens by the floods of several years, and which collect in deep holes, till, overcharged with numbers, they are obliged to attempt a change of place. The quantity may perhaps be conceived from the fact, that a man employed in collecting them, gained for a considerable time four shillings a-day by selling them at the rate of a halfpenny a bushel. Some of the *Gasterostei* live indifferently in salt or fresh water, and the one represented by figure 13 was taken by Sir Edward Belcher, in the sea at the north end of Wellington Sound, in Lat. 7° N. M. Coste, who studied the manners of these small fishes in the Mediterranean, relates that on the approach of spawning time, the male builds a nest of stalks of grass and other matters in a hollow of the bottom, a little above three feet wide and about six inches and a half deep, creeping over the materials on his belly and cementing them with the mucus that exudes from his skin. The bottom of the nest is first laid, then the sides are raised, and lastly, the top is covered over. A small hole is left on one side for an entrance. When the erection is complete, he seeks out a female, and conducting her, M. Costa says, with many caresses, to the nest, introduces her by the door into the chamber. In a few minutes she has laid two or three eggs, after which she bores a hole on the opposite side of the nest to that by which she entered, and makes her escape. The nest has now two doors, and the eggs are exposed to the cool stream of water which entering by one door flows out at the other. Next day the male goes again in quest of a female, and sometimes brings back the same, sometimes finds a new mate. This is repeated until the nest contains a considerable number of eggs, and each time the male rubs his side against the female and passes over the eggs. Next the male watches a whole month over his treasure, defending it stoutly against all invaders, and especially against his wives, who have a great desire to look at the eggs. When the young are hatched and able to do for themselves, his cares cease. Mr Lecoq made similar observations at another place, but the Italian society to whom the papers of the two observers were transmitted, after inquiring fully into the case, decreed that the right of priority belonged to M. Coste. (Archivien für Naturg.)

**FAMILY VII.—SCLEROGENIDÆ.**

*Jones curvirostris*, Cuv.; *Catophractoides*, Cant.; *Tripida*, Bonap.; *Catophractis*, Heck.; *Scleropari*, Buceroticus, &c.

The distinctive character of this group is the prolongation of the second suborbital scale-bone across the cheek to be articulated with the preoperculum in its curve, so as to serve for a fulcrum to the spine, which issues from the angle of that bone. Forms exceedingly variable, but having a family resemblance in their prevailing monstrous character. Several genera have fewer than five rays in the ventrals, an uncommon occurrence among Acanthopteri. Genus I. Trachys, Linn. Cheek wholly covered by the enormous second suborbital, which is articulated by an immovable structure to the preoperculum, the two moving together; sides of the head smooth and vertical. Body scaley. Two dorsals. Three free unbranched articulated rays under the pectoral. Scoot formed by the union of the prefrontals, turbinals, and point of the nasal, by nature; the preorbital making a more or less salient projection before them. Branchiostegals seven. Branchial rakers in form of tubercles; villiform teeth on the jaws and pharyngeals, but the vomer and tongue are edentate. Lateral line straight to the caudal, on which it forks; it is variously armed. Stomach cecal; pancreatic ceca numerous (eight to twelve), dividing into two or three lobes anteriorly. Eighteen species.

Genus II. Pterichthys, Cuv. Triplette with very large pectorals and villiform palatine teeth. Body scaley. Eight species.

Genus III. Periactisodon, Lacép. Body clothed in scaly armour; a long projection of the preorbital on each side of the scoot. Mouth beneath; dentition of teeth, as are also the vomer, palatines, and pharyngeals. Under lip bearded. Body octagonal, with tapering spines on its eight angles. Two free rays under the pectoral. Pancreatic ceca seven; air-bladder pretty large, simple. Two species.

Genus IV. Dactylopterus, Cuv. Head flat above, rounded off into a nearly vertical face; helmet granulated. Eye very large. A very long spine continued from the lower border of the opercular column. Suprascapula emitting a long spine; articulation of the suborbital and preoperculum moveable. Teeth villiform-like on the jaws; no teeth on the vomer or palatines. Branchiostegals six; four articulated rays only in the ventrals in addition to the spine. No free rays in the pectorals, but the fin is divided into a smaller anterior part, and a posterior very broad and long part with the tips of the rays going beyond the membrane; some of the anterior dorsal rays are free. Scales of the body hard and firm, those on the flanks keeled, forming, by their close succession, trenchant crests. Stomach cecal; about thirty pancreatic ceca in two bundles; air-bladder small, deeply bilobate. Two species.

Genus V. Cephalacthys, Lacép., is a Dactylopterus without the wing-like supplementary pectoral, or a Triplette without the free rays. Head and body like Dactylopterus, of which it is said by Dumeril to be merely the young. An acute and very long spine from the angle of the preoperculum, and another from the suprascapula, both serrated, the dorsal divided into two nearly equal lobes by a fissure. A pointed cecal stomach; innumerable pancreatic ceca; air-bladder. One species.

Genus VI. Cottus, Linn. A large rounded or depressed head, variably armed with spines and tubercles. No scales. Two dorsals. Teeth on the fore-part of the vomer; no teeth on the palatines. Six branchiostegals. Five, four, or fewer rays in the ventrals; inferior rays of the pectoral unbranched as in Trachysoma. Pancreatic ceca few in number; no air-bladder. Thirty-five species. Various dismemberments of this genus have been made, and the fresh-water and marine species have been separated. Ursidium being the name given to an American fresh-water species, and Acanthocetus to the marine ones.

In the fully armed head of a Cottus there are ten spinous points more or less produced on each side of the head; one on the tubercle; five on the preoperculum, the one at the angle being a long spine; and the others angular points of the inferior limb; one on the inferior, anterior angle of the suboperculum; a spine at the point of the operculum, and acute points or spines on the suprascapula and coracoid. There are also four eminences placed in a quadrangle on the top of the head, one behind each orbit, and another on the occiput on each side. In some these are blunt and smooth; in others spinous; in others rough tubercles, much elevated or even branched. In other species many of the spinous points are obsolete.

Genus VII. Trachydoros, Heck. (Cottusdendrophilus, Rich.) General form that of Cottus; head less depressed. Turbinals, preoperculum, and inferior angle of the suboperculum spinous; the principal preopercular spine hooked. Beneath it two acute spines and a blunt third. Preoperculum and preopercular unarmed. Villiform teeth on the jaws, palatines, and chevron of the vomer; pharyngeal teeth rather coarser, the upper ones forming a tuft on each side. Dorsals contiguous; pectorals like those of Cottus, with simple rays below (seven); ventrals having four jointed rays and one spine. Branchiostegals six. Body covered with slender reticulate spines, each springing from a minute cuticular tubercle. Head, belly, axillae of the pectorals, and a narrow line along the base of the anal, smooth. A genital papilla; pancreatic ceca. Species Tr. omanu, China.

Cottus argus (Fauna Bore. Amer.) seems to be a second species of Trachydoros, with the spines on the same bones of the head, but less prominent, so as to be concealed in the recent fish by the integuments, and the point of the principal preopercular spine not hooked. It is the type of the genus Cotogaster, Girard.

Genus VIII. Triglopsis, Gir. Head smooth. Many muciferous canals developed in the bones of the skull and face, as in Classification. Acarina. First dorsal shorter and much lower than the secondaries, and distant from it. No palatine teeth; teeth on the cheeks of the Acanthopterous, and also down the median line. Four short preopercular spines; shorter and more slender than is usual in Cottus. Gill-openings connected on the throat without an isthmus. Branchiostegals six. All the pectoral rays united. One species, Lake Ontario.

Genus IX. Pristurus, Kroy. Cottus destitute of vomerine teeth, resembling Cottus Scoparius in general aspect. Acute small turbinal spines. Principal preopercular spine snagged; three acute points on the bone beneath it; operculum destitute of both the usual median rib and spine. A small spine pointing downwards from the lower angle of the suboperculum, and crossed by a smaller interopercular spine. Suprascapula unarmed. Two small cranial tubercles on each side. No orbital ridges. Lateral line composed of cutaneous mucoiducts. Fins large.

Genus X. Icelus, Kroy. Body somewhat compressed, higher than thick. Head large; distantly separated eyes; armed with spines on the snout, preoperculum, and nape. Teeth minute, setaceous on the jaws, vomer, palatines, and pharyngeals. Branchiostegals six. Two dorsal rays; ventrals consisting of four rays under the pectorals; rays of the fins undivided. On each side from the nape to the caudal fin a continuous series of bony shields, running near the dorsals. Lateral line composed of bony tubercles. Ciliated scales on the sides and belly, few and scattered; the rest of the skin naked. Three species, I. homatus, I. bicirris, I. unicirrus.

Genus XI. Caracanthus, Kroy. Body higher than in other genera of the family, greatly compressed, oval. Scoot very short, truncated; small slender teeth on the premaxillaries and mandible. Branchiostegals six. Preorbital scale short armed with a spinous point anteriorly. Two low dorsal fins; short pectoral fins, with simple rays; ventrals entirely rudimentary; two spinous anal rays, set apart from the soft portion of the fin. No scales, but many cutaneous papillae. One species, Osteithele.

Genus XII. Podarchus, Rich. 1848. Scaleless. Lateral line of simple cutaneous mucoiducts, arched abruptly over the pectorals. Ventrales of a spine and two soft rays; two dorsals approximated; rays of all the fins, except the caudal, unbranched; none free. Villiform bands of sabulose teeth on the jaws, vomer, and palatines, and in hemispherical tufts on the pharyngeals, also on the preopercular rakers. Tongue smooth. No armature on the preopercular, suboperculum, or interoperculum, nor on the cranial or suprascapulae. Slight unevenness of the skin concealed by the soft parts. A narrow, thin process projects from above the corner of the preoperculum; and the operculum ends in a thin flexible point, but there is no pungent corner, and the integuments of the cheek conceal the second preorbital as it crosses to the hollow of the preoperculum. One species has the aspect of Centropomus, another of Cottus, both are more compressed than Cottus. Two species, China seas.

Genus XIII. Aspidophorus, Lacép. Palangista, Bloch. Schneider. Many of the characters of Cottus, such as the depressed head, simple rays, six branchiostegals, but with the body enlarged by a series of large bony scales that extend from the head to the caudal fin, forming a pyramid with many faces. No vomerine teeth. Ten species.

Genus XIV. Platycephalus, Bloch. Head very much depressed; spinous. Body more or less depressed; elongated; scaley. Acute teeth on the palatines. Seven branchiostegals. A spine and five articulated rays in the ventrals, which are under the middle of the branchiostegals, and therefore abdominal in position, and are widely apart from each other laterally, owing to the breadth of the public bones. Dorsals contiguous or approximated. Thirty species.

Genus XV. Oligolepis, Cuv. Head depressed, and with the operculum very spinous as in Platycephalus. Body enlarged as in Aspidophorus. Ventrales more jugular, and having a spine and five soft rays. One species, Japan.

Genus XVI. Hemilepidotus, Cuv. Two dorsals, the first one deeply notched. Many cutaneous filaments on the uneven head and mandible. Large pectorals advancing far under the throat; the lower rays thickened, but none free; ventrales jugular of a spine, four broad. Tongue smooth. Branchiostegals six. Two species, genus of Cottus, but with the dorsals united, though notched between the spinous and soft portions. Teeth on the jaws, vomer, and palatines. Two ranges of scales on the sides with soft integument between them; scales round, finely denticulated, and rising into a little crest. Stomach small; pancreatic ceca five.

Genus XVIII. Hemilepidotus, Cuv. Head, serrated crests, and spines, nearly as in Platycephalus, but not depressed. Ventrales rather before the pectorals, with five articulated rays and the usual spine, and as in Scorpaena there are villiform bands of teeth Genus XXVII. Choridactylus, Rich. (Voy. of the Sulphur, 1848). This genus combines the characters of various Scorpaenidae in union with the preorbital spines of Apistus or Minous; it has the hollow cheeks, prominent orbits, tall, slender, elongated spines, filaments of the fins, three free pectoral rays, and ventrals limited to the belly, and composed of five soft rays and a spine, all as in Peler. It has not, however, the elongated body, depressed head, and horizontally protruding muzzle, nor the vomerine teeth of Peler, and of the Scorpaenidae generally; it is distinguished from Symaceria by its free pectoral rays, but resembles that genus in general form. Skin scaleless. Many filaments on the head, mandible, and fins. One species.

Genus XXVIII. Stenopus, Rich. (Ibid., supra cit.) Aspect of Peler, with a less extraordinary-shaped, though large head, and three higher rays in the dorsal, advanced to the orbits, but connected at the base by filaments to the remainder of the fin. Only two soft rays and a spine in the small ventrals which are under the base of the pectorals. No pungent points on the bones of the head and face, which are clothed with soft, thick, leathery integuments. Skin of the body destitute of scales, but covered in certain parts, especially along the lateral line, with small cutaneous filaments, which extend also to the head, pectorals, and dorsal. Pectorals attached differently from those of Symaceria. Teeth on the jaws and chevron of the vomer; none on the palatines. The second suborbital, which traverses the cheek, is a narrow plate that descends from the orbit to the curve of the preoperculum; the preorbital is subulate with a cartilaginous tip. One species.

Genus XXIX. Velox, Cuv. Head as it were broken down above, with prominent orbits approximated to each other. High and almost isolated dorsal spines. No scales. Bands of fine villiform teeth on the jaws and front of the snout; none on the palatines or tongue. Two free rays under the pectorals. No preorbital; no preorbital spine of the preorbital of Apistus is absent, by which they are separated from the species of that genus with naked skin; but there are angular points on the preorbital, and still more prominent ones on the preoperculum, operculum, supracaudal, and cornoid. Stomach caudal; four thick pancreatic caeca; an air-bladder scarcely as big as a pea placed near the pylorus. Seven species.

Genus XXX. Symaceria, Bloch, Schmid. Destitute of spines on the head, which is not more compressed than that of many Coti. Teeth on the jaws, but none on the vomer or palatines; no free rays under the pectorals, but the tips of the anterior rays project considerably in some species. Mouth vertical as in Urocerus; the mandible being in front when shut; this form of mouth, five soft rays in the ventrals, and the want of vomerine teeth, distinguish the genus from Sibagonus. Skin scaleless, smooth and slippery. Eyes in some lateral, though high on the head; in S. asterocera very small, and on the dorsal aspect of the head. Stomach oval, caudal; four thick pancreatic caeca; air-bladder simple, small in the fore part of the abdomen. Twelve species.

Genus XXXI. Apogon, Cuv. One of the least armed of the family, and the second suborbital does not articulate opposite the angle of the preoperculum, but to the upper part of the ascending limb of that bone. A long single dorsal, with strong spines advancing on the cranial to between the orbits, with its anterior rays flanked by elevated uneven cranial crests. Mouth projecting, small, furnished with scarcely perceptible teeth; no teeth on the palate or tongue. Five branchiostegals. Pectorals low down, the membrane between the lower rays prolonged into ventrals with a spine and five soft rays; caudal rays subdivided; rays of all the other fins simple. Skin scaleless, smooth, or finely reticulated. Stomach siphonal, without a dilatation to distinguish it from the esophagus; no pancreatic caeca; air-bladder oral, occupying half the length of the abdomen. This genus and Pterois seem to link the Scorpaenidae and Gobiidae to each other. Four species.

Genus XXXII. Monocentris, Lacép. Very different in aspect from the other members of the family, but having the distinguishing character of the group in the suborbital crossing the cheek to the preoperculum. Body thick and short, encrusted by enormous rough scales or keeled scales. Four or five thick spines not connected with membranes form an anterior dorsal; ventrals having one enormous spine, and four, four small, almost invisible rays in its axilla; Face bulging. Villiform teeth on the jaws and palatines; none on the vomer. Eight branchiostegals; soft dorsal and anal opposite, and far back. One species.

Genus XXXIII. Trachichthys, Shaw. (Hoplostethus, Cuv.; Hist. des Poissons, iv., 470, and iii., 229.) Form oval, to which the tail behind the anal is to be added. Face very convex; mouth terminal, descending obliquely. Eye very large. Top of the head and cheeks cellular, from the prominence of branching bony crests, which on the cheeks radiate from the suborbitars. Operculum and disk of the preoperculum striated; a spine from the angle of the mouth; a small spine terminating a ridge on the upper part of the operculum; a flat rough spine on the supracaudal, and one on the mastoid. One species; ventrals under the pectorals of six soft rays and a spine; the free rays of all the fins branched. Belly serrated behind the ventrals. Caudal deeply forked. Two species.

Genus XXXIV. Chirus, Steh. Pretty long compressed scaly fishes, with a small unarmed head. Scales elutinant. Cheek traversed. by the second suborbital, as in the other Seleneidae; distinguished by having several (generally five) lateral lines at various heights. Mouth small. Dorsal nearly even, extending all along the back; its spinous rays slender; ventrals of five rays and a spine. No pancreatic cecae. Frequently a tufted filament on the eye-brows. Ten species.

The genus Stickenia of Reinhardt (Overzigt over det Kongelige Danske Vid. Selsk., etc., 1825-6) should come in here, but we have not at present access to Reinhardt's paper.

**SCOLENOIDS.**

Several genera have been removed from this family as it was presented in the *Histoire des Poissons*, particularly the groups which have a lateral line broken or interrupted under the distal end of the dorsal fin. These form the Ctenoid Labroids in the order of Pharyngognaths already treated of. We have also associated the genera that have fewer branchiostegals than seven with the Theraponidae, and Cheilodactylus with the Polynemidae. These being removed, the remainder present a more perfect family aspect.

**TABLE OF GENERA.**

Two dorsals, or one dorsal deeply notched.

No mandibular barbels.

No strong canines.

Denticulated preopercula.

No large smooth rounded teeth.

Smooth convex, bulging.

*Selena, Corvina, Leistomus, Johnius.*

Snout not convex nor high and rounded.

*Larimus, Lepidurus.*

Large pavement-like teeth on the jaws.

*Boridia, Conodon.*

Preopercula not denticulated.

*Nebrius, Eleginus.*

Strong canine teeth.

*Otolithus, Angeldon.*

One or more mandibular barbels.

*Umbra, Longchirus, Pogonias, Micropogon.*

One dorsal only.

*Hemulon, Pristipoma, Diagramma.*

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This woodcut represents a fresh-water Corvina, common in Lake Huron. We have, however, some suspicion of its belonging more properly to the Theraponidae than to the Sciaenidae, notwithstanding Cuvier's weighty authority. It has only six branchiostegals.

Many members of this family have curious air-bladders with fringe-like appendages. The subjoined woodcuts represent that of *Corvina acrepa*, and of *Pogonias chromis*. One of the most remarkable of the Sciaenae is the *aquila*, called *Udorina* by the Romans, and held in high esteem in the Mediterranean even at the present day. It is very rare on the British coasts. Dr Patrick Neill records one instance of its capture off Ugea in Northmavine, Shetland, in November 1819. When first seen, it caught the attention of the fishermen by its endeavours to elude the pursuit of a seal. It measured five feet four inches, and when lifted into the boat made its usual "purring sound." Mr Yarrell mentions some subsequent instances of its being taken on the Northumberland and Kentish coasts. It is much more common in the Mediterranean, and Paul Jovins says that many were taken at the mouth of rivers in the Roman states, along with Sturgeons. They swim in troops, and are said to utter at times a low bellowing sound. On one occasion, the fishermen, guided by this sound, dropped their net with such success as to secure twenty fine fish at a single cast. The noise may be heard from the depth of twenty fathoms, and is often very perceptible when the ear is placed upon the gunwale of the boat. Its tone seems to vary, as some have compared it to a dull buzzing, others to a sharp whistle. Some fishermen allege that the males alone are musical during spawning time, and that it is quite possible to capture them without any bait, merely by imitating this peculiar sound. One alluded to by Cuvier as having been entangled in a net spread along the shore at Dieppe, was at first found sleeping; but on being handled it roused itself so suddenly, and with such violence, as to precipitate the fisherman into the water, and force him to call for assistance before he could become its master. High, though of course imaginary virtues, were formerly attributed to the stones which occur in the ear of this, as of other osseous fishes. They were worn on the neck, set in gold; and Belon says they were called colic-stones, being renowned for the cure, and even prevention of that complaint. It was necessary, however, that they should be received as a gift, such as were purchased being found to lose their virtue.

The *Pogonias* grow to a great size, some of them weighing occasionally above a hundred pounds, and the singular sounds uttered by them have gained them the vulgar name of *Drums*. Mr John White, an American lieutenant, who (in 1824) published *A Voyage to the China Seas*, relates, that being at the mouth of the River Cambodia, himself and crew were greatly astonished by certain extraordinary sounds, which were heard from around and beneath the vessel. They resembled a combination of the bass of an organ, the sound of bells, and the guttural cries of a large frog, with certain tones which the imagination might

Genus II. Otolithus, Cuv. Scienoid also with feeble anal spines and no barbels, but having long canine teeth or canines among the others. Air-bladder having a horn-like projection on each side in front; four pancreatic ceca. Eighteen species.

Genus III. Anguillon, Cuv. Otolithus with a very short snout, excessively long canines, and a pointed tail. Two species.

Genus IV. Corvina, Cuv. Scienoid with wholly villiform teeth and no barbels, but differing from Scienoid and Otolithus in the great size of the second anal spine. Nineteen species.

Genus V. Johnius, Bloch. Considered by Cuvier to be like Corvina and Otolithus, a subdivision of Scienoid, and distinguished chiefly by the second anal spine being weak and shorter than the soft rays of that fin. Eighteen species.

Genus VI. Lepidostomus, Cuv. Johnius in having a small anal spine or feeble denticulations in the preoperculum; but the teeth of the jaws so fine as to be with great difficulty seen; pharyngeal teeth pavement-like; mouth large; horns of the air-bladder smaller and more slender than in Otolithus. Two species.

Genus VII. Larimus, Cuv. One of several anomalous Scienoid forms, which have characters different from those of the foregoing groups. Two dorsals. Villiform teeth. Forehead not arched; snout short; preoperculum slightly denticulated. Stomach caecal, narrow; eleven pancreatic ceca; air-bladder large, simple. Two species.

Genus VIII. Nibbles, Cuv. Scienoids with two dorsals. Villiform teeth. Profile nearly straight; snout short; mandible ascending. Lips of the third preoperculum membranous, and merely striated, and the fin less more or less scaly. One species.

Genus IX. Lepidurus, Cuv. Scienoids with villiform teeth, prolonged snout, profile rather concave, and very scaly vertical fin. One species.

Genus X. Boridius, Cuv. Corvina with smooth blunt teeth on the jaws. One species.

Genus XI. Conodon, Cuv. Scienoids distinguished from the others by having a row of conical teeth on the two jaws. One species.

Genus XII. Eleocharis, Cuv. Scienoids with an entire preoperculum. Mouth small. Anal long. Two short conical horns in the fore part of the air-bladder. Three species.

Genus XIII. Equus, Bloch. Resemble Scienoid, Corvina, Johnius, in their convex snout, scaly throughout, like the rest of the head; in the mucous pores and pits of the lower jaw; in the upper jaw being able to retire under the edge of the preorbital; in the length of the second dorsal; in the shortness of the anal, both of them scaly as well as much of the caudal. Teeth villiform, and not elongated like those of the Chondrostomus. Eques the body is compressed, and by the convexity of the nape assumes a semicircular outline. Branchiostegals seven. Faint cremastrae on the preoperculum; the bony frame of the operculum ends in two flat points. The first dorsal is high and peaked with mostly flexible rays; second dorsal low and long; caudal rhomboidal; ventrals longer than the pectorals. A small membrane in front of the snout, with a pit on each side between it and the high preorbital. A small pore beneath the mandible on each side of the median line. A large silvery air-bladder (air-sacs); four pancreatic ceca. Three species.

Genus XIV. Umbrina, Cuv. Scienoids having one barbel under the mandibular symphysis. Thirty species.

Genus XV. Lophurus, Cuv. Umbriae with two mandibular barbels and a pointed caudal. Two species.

Genus XVI. Pogonias, Lacép. Umbriae with many small mandibular barbels. Lower pharyngeal teeth and middle upper ones large like those of Labeus. Two species.

Genus XVII. Micropogon, Lacép. Scienoids with a prominent nape like Corvina. Moderate-sized anal spine, and very small and numerous barbels. Distinct denticulations on the ascending limb of the preoperculum, those at the angle being larger; operculum ending in two flat points. Membrane at the end of the snout four-lobed. Mouth moderately protrusible; pretty broad bands of villiform teeth; pharyngeal teeth villiform, the middle ones being larger, with obtuse serratures. Under the mandible there are symphyses two large pores and three small ones; three or four little barbels attached to the limb of the mandible. Scales slightly rough and oblique as in the Scienoids in general. Dorsal spines not very strong; slender ventral spine, and the anal spine shorter than the soft rays; caudal nearly even at the end. Three species, America.

(a.) Two dorsals, or one deeply notched.

Genus I. Scienoides, Cuv. Head convex, with cellular bones. Two dorsals, or one dorsal deeply notched; and the soft part much longer than the spinous one; a short anal. Preoperculum denticulated; operculum ending in points. Seven branchiostegals. Otolithes larger than in most fishes, and the air-bladders large and complicated. The proper Scienoides have feeble spines in the anal, and are destitute of canines and barbels. Stomach caecal; ten pancreatic ceca or more. Four species.

(b.) A single dorsal; preoperculum always denticulated.

Genus XVIII. Hamulon, Cuv. Body oblong, pretty high anteriorly, somewhat compressed. Profile descending almost in a straight line, and forming a snout that projects tolerably. Preorbital large, but not denticulated, covered with skin and scales, joining the cheek as in the Scienoides in general, and forming a ledge under which the moderately protrusible upper jaw retires. Lips fleshy. Mandible articulated under the eye, having an oval pit The best-known species inhabits the Mediterranean. It is the *S. Rondelii* of Cuv. The American shores produce several others, one of which (*S. ovus*) is called the *Sheep's-head* by the Americans. Dr Mitchell speaks in the most eulogistic terms of the superexcellence of its flesh, and of the high esteem in which it is held at the tables of New York. It yields in his opinion to few fishes, and is worthy of being served at the most sumptuous entertainments. The price varies from a dollar to a dollar and a half; for a middle-sized individual, and above that size the price ranges even so high as from L4 to L7 sterling. They sometimes weigh from 14 to 15 lbs. The fishery of this species forms an object of importance along the coasts of the state of New York. It approaches those of Long Island in the hot season from the month of June till the middle of September, after which it seems to seek retirement in the deep abysses of the ocean. As they swim in troops, they may be advantageously fished for with the net, and many hundreds are sometimes taken at a single cast. With the great nets used at Rayner Town, and the two islands, thousands are drawn ashore. They are immediately packed in ice, and despatched during the cool of the night to the markets of New York. It is difficult to take the *Sheep's-head* with a line, because it contrives to snap the very hooks asunder with its cutting teeth.

The species of *Chrysophris* are numerous, and extended through many seas. Those of the Mediterranean are only two in number, and are called *Daurades* by the French, no doubt from the Latin *Aurata*, a term applied to them by ancient authors. The Greeks named them Chrysophris, which signifies golden eye-brow, in allusion to the brilliant spot of gold which the common species bears between its eyes. That the *Aurata* of the Latins was identical with the *Chrysophris* of the Greeks, may be inferred from a passage in Pliny, which is obviously borrowed from Aristotle, and where the former word is used as the translation of the latter. According to Columella, the Aurata was among the number of the fishes brought up by the Romans in their *vivaria*; and the inventor of these vivaria, one Seranus Orata, is supposed to have derived his surname from the fish in question. Ælian tells us that the Chrysophris is the most timid of all fishes, and that branches of poplars planted in the sand so terrified a party of these fishes which had been carried upwards by the flood, that in the succeeding reflux they did not dare to pass the poplars, but allowed themselves to be taken by the hand. The *Chrysophris aurata*, or *Gilt-head*, seldom quits the vicinity of the shore, and grows extremely fat in the salt ponds. We owe to Duhamel whatever information we possess regarding its habits. The fishermen informed that author that it agitates the sand forcibly with its tail, so as to discover the shell-fish, which may lie beneath concealed. It is extremely fond of mussels, and its near presence is sometimes ascertained by the noise which it makes while breaking their shells with its teeth. It greatly dreaded cold, and many were observed to perish during the severe winter of 1766. The Gilt-head is a British species, but of extremely rare occurrence.

The Dentex vulgaris, a fish of a silvery hue, shaded into blue upon the back, with reddish pectoral fins, and sometimes attaining to the weight of 20 lbs., has occurred upon the Sussex coast. The specimen figured by Donovan (pl. 73) was obtained in Billingsgate market.

Fig. 31 represents a scale of Lethrinus cynocheilus, and may give some idea of the general character of a Sparoid scale, alluded to in the table of genera at the bottom of the page.

**Family IX.—SPARIDÆ.**

Sparoid scales; a large elongated scale in the axilla of the pectoral. Gill-cover shining, without proper spines or denticulations. Maxilla capable of being received in part under the preopercular scale bone, which is generally high. Spinous rays of the dorsal and anal fins bare, mostly lodging in a furrow; pectoral and ventral fins sharp pointed; caudal fin notched in an angle at the end. The Sparoid scales are generally thin, broader than long, and the centre of growth is near the posterior border, the lines being parallel to the anterior border, and becoming straight laterally. Their peculiar structure is described more fully in Agassiz, *Pisces*, l. p. 88, and in Trochel's *Arch.* for 1849, p. 382. Smoot not projecting nor protractile, destitute of palatine teeth, and distinguished from the Scombrids by the want of any denticulations or armature of the gill-covers, and of cavernous or cellular structure in the cranium; from the Chondrosteidae, by the want of scales on the vertical fins; and by the size and nature of the scales from the Scorpaenidae (*Hist. des Poissons*). Branchiostegals generally six, sometimes five, rarely seven.

(a.) Round molar teeth, with trechant or conical front ones.

**Genus I. Sargus, Cuv.** Several rows of molars; incisorial front teeth. Cheek scaly. Sixteen species.

**Genus II. Charax, Risso.** One row of very small molars almost granular; incisorial front teeth. Cheek scaly.

**Genus III. Chrysophrys, Cuv.** Several rows of rounded molars; front teeth conical. Cheek scaly. Twenty-four species.

**Genus IV. Pagellus, Cuv.** Rounded molars in two rows; front teeth conical, with a villiform card-like band behind them. Cheek scaly. Fifteen species.

**Genus V. Pagellus, Cuv.** Two or more rows of rounded molars; front teeth villiform. Cheek scaly. Twelve species.

(b.) Teeth conical, with larger ones, or canines.

**Genus VI. Lethrinus, Cuv.** Teeth villiform, mixed with long curved ones, and occasionally one or two rounded molars. Cheek naked (without scales). Twenty-eight species.

**Genus VII. Dentex, Cuv.** At least four large canines among villiform or card-like teeth. Cheek scaly. Thirty species.

**Genus VIII. Pentapodus, Cuv.** Cheek scaly. Teeth villiform, with only two canines; mouth small. Caudal more scaly than in Dentex. Eight species.

(c.) Teeth all villiform.

**Genus IX. Cantharus, Cuv.** Villiform teeth, the exterior ones stronger. Twelve species.

(d.) Trechant teeth without molars, sometimes accompanied by villiform bands, sometimes without them; no rounded molars.

**Genus X. Box, Cuv.** A single row of thin vertical teeth notched or crenated on the edge. Six species.

**Genus XI. Orata, Cuv.** Crenated cutting teeth as in Box, with a villiform band behind them. Two species.

**Genus XII. Bonodon, Guich.** Body elongated, roundish, covered with small scales. Snout short; mouth small, not protractile. No teeth whatever. Opercular bones not denticulated nor serrated. Eyes large. Dorsals two, with many free spines between them; ventral fin minute, situated on the thorax. Branchial opening wide; branchiostegals six. Valparaiso.

**Genus XIII. Scatharus, Cuv.** Cutting teeth not crenated in a single row. One species.

**Genus XIV. Creidens, Cuv.** (*Girella, Gray; Melanichthys, Schleg.; Fusca Jap.*) Oval scaly fishes, with a nearly even dorsal having many spinous rays. Convex profile; terminal small mouth and head wholly unarmed. Ventrales consisting of a spine and five soft rays under the pectorals. Scales ctenoid, in some covering all the head except the disk of the preoperculum, mandible, and lips; in other species have more or most of the opercular pieces scaleless; narrow vertical bands of scales exist on the fins in some species, but are easily deciduous. Teeth compressed, curved, crenated with three or more disks, rarely entire, forming two rows on the jaws, and separated by a furrow from an interior band of minute teeth appearing to be granular, but when examined with a lens showing the same forms with the exterior older ones which they are destined to succeed. Vomer and palate generally toothless. In C. simplex, a species with entire incisorial teeth, the vomer is furnished with a patch of minute teeth invisible to the naked eye, and there is a similar plate on the front of the palatines. Pharyngeal teeth small, short, subulate, and densely crowded. Branchiostegals six. Six species.

**MENOIDÆ.**

This family is distinguished from the Sparoids by the protractility of the mouth, and by a greater thickness of the face and of the body generally. The Mediterranean species were known to the ancients, and their Greek name is Latinized by Pliny to *Menia*, and adopted by Cuvier as a generic term. They are mostly small fishes, despised by the ancients, and held in no great esteem now.

"Putisse gerres aut inutilis maxenas, Odor impudicus uroel fatetatur."

**MARTIAL.**

The following table of the genera is from the *Histoire des Poissons*, the source from which our observations generally are drawn:

### TABLE OF GENERA.

**Menides.** Form sparoid, but having occasionally teeth on the palate, or denticulations on the preoperculum. Mouth in all cases very protractile.

No scales on the dorsal fin.

**Menia, Smaris.**

Scaly dorsal.

**Cesio, Gerres.**

The other genera are characterized by ichthyologists who have written subsequently to the publication of the volume of the *Histoire des Poissons*, which contains the *Menidae*. The genus *Emmelichthys* is one of those which combines the characters of several groups. It has much affinity to Cassio, but differs in having seven branchiostegals, a deeply and widely notched dorsal, approaching more nearly to two dorsals than Gerres, scaly sheaths to the vertical fins of a different character from the scales that invest the fins in these two genera; and the snout, gill-covers, and maxillaries more strongly and more completely scaly. It is not without a resemblance to several of the genera assembled under the head of Theropoidae. To Glaucomoma it approaches in the extent of scaliness of the head and fins, but differs greatly in aspect, dentition, branchiostegals, and especially in its protractile mouth. From the typical Percoidea, with which it agrees in having seven gill rays, it is kept distinct by its unarmed head; the want of mandibular pores will not allow it to associate with Hemulon, Pristipomaa, or Diagramma; and it bears little resemblance in its spiny scales to the oblique-scaled typical Sciaenidae, from which also its elongated face distinguishes it. The want of teeth is a character which it has in common with Boaxodon and Macquaria, but the latter has only five branchiostegals. It is a genus recently discovered in the Japanese and Australian seas. Fig. 18 shows the protractile mouth of Emmelichthys mitidus, with the scales on the maxilla; Fig. 105 gives a figure of the entire fish, and Fig. 106 represents one of the scales.

Concerning the Pseudochromide we have almost nothing to say. The genera are not described in the Histoire des Poissons, and but little is contained in the Regne Animal concerning them. Indeed, a brief notice of the names of the genera composing the family given in the Archicon fur Naturgeschichte, is our only authority for introducing it here. In the Regne Animal, Plesios and Cichlops were placed among the Labroids, but M. Valenciennes states, in 1839, that having studied at Leyden the fish sent from Java, by Kubl and Van Hasselt, he was convinced that the Plesios and Cirrhipteri of these naturalists could not remain in the Labroid family. Willughby had already noticed the existence of two small pancreatic caeca in Chromis (Sparus chromis, Linn.) ; and M. Valenciennes finds it to agree so nearly with Plesios, as not to be generically distinct. Their teeth, the interrupted lateral line, constitution of their scales, and the filaments of the spinous dorsal rays are alike in both. Cuvier, in stating that the Chromides had no pancreatic caeca, had in view the Bolti or Labrus niloticus, which, in fact, wants these organs. In conclusion, M. Valenciennes is inclined to place the genera in question with the Glyphodonidae and their allies. Muller, finding a coalesced pharyngeal in Chromis, has introduced it as the type of a family among the Pharyngognathi, referring the Pseudochromide to the Acanthopteri.

Family X.—Menidae.

Les Menides, Cuv. Distinguished from the Sparidae, which they resemble, by the protractility of the mouth. Villiform teeth on the jaws more or less short. Premaxillary pedicels long, admitting of the body of the bone being thrust out horizontally when the mandible is long in proportion, but when that bone is abbreviated then downwards. Some genera want teeth on the palate, others have small ones on the vomer. Body scaly. Ventra situated under the pectorals; dorsal furnished with very fine scales. Stomach of moderate size; pancreatic caeca varying from four to seven; air-bladder large, simple, and rounded anteriorly, divided for the most part into two lobes posteriorly.

Genus I. Menidi, Cuv. Aspect of a Sparoid, but occasionally having teeth on the palate, and a denticulated preoperculum. Mouth invariably very protractile. Four species.

Genus II. Smaris, Cuv. No scales on the dorsal. Palate toothless. General form of Menida. Ten species.

Genus III. Cassio, Cuv. Mouth but little protractile. Dorsal far back, and in a great part covered with scales. General shape inclining to fusiform. Twelve species.

Genus IV. Gerres, Cuv. Mouth very protractile, descending when thrust out. Dorsal capable of being concealed in a basal scaly sheath. Small villiform teeth on the jaws, none on the palate. Preoperculum finely denticulated. Body compressed, elevated. Scales large, deciduous. Ventra under the anterior third of the pectorals. Classification—Twenty species.

Genus V. Emmelichthys, Rich. (Emmelichthys, Schleg.) Acanthopterous fishes. Forms of the body that of Saeris or Cassio. Dorsal more deeply notched than that of Gerres, the last two or three spinous rays being almost detached. Very slender saecaceous pharyngeal teeth; none on the mouth. Jaws moderately protractile directly forwards. Head and body, and bases of the vertical fins, scaly. Scales ctenoid. No spines on the head. Preoperculum and suboperculum very minutely crenulated. Supraoccipital irregularly denticulate. Branchiostegals seven. Two species.

Genus VI. Ditrema, Schleg. Jaw teeth minute, pluriseriatus, with a few conical ones in front; no vomerine or palatine teeth. Snout a horizontal protractile tube. Opercular pieces and suborbital scale bones not denticulated. Dorsal single, low; anal and ventral apertures separate; dorsal having three spines and numerous simple rays. Branchiostegals six. Macasar.

Genus VII. Apogonoides, Bleek. Saecaceous maxillary teeth; no teeth on the vomer or palatines. Opercular bones not toothed; no opercular spine. Mouth little protractile. Dorsal two, remote, not scaly. Branchiostegals six. Macasar.

Genus IX. Mendosoma, Guichen. Body oblong, compressed, scaly, with the aspect of Menida. Head small; mouth protractile, with a very small opening; many conical teeth near the premaxillary symphyses only; no teeth on the mandible or vomer. Dorsals two, continuous, or one fin notched to its base. Ventra thoracic, destitute of the long scaly scales. Branchiostegals six. Batavia.

Genus X. Pentapodus, Bleek. Dorsal solitary. Mouth protractile downwards; teeth on the jaws only. Spinous anal rays five. Branchiostegals six. Batavia.

Genus XI. Velifer, Schleg. Near Cassio and Gerres. Body very high and compressed. Dorsal and anal fins excessively large, and supported by soft, thick, unjointed rays. Japan.

Genus XII. Acharnus, Mull. and Troesch. Distinguished among the Mesidae by the interrupted lateral line. Teeth on the jaws cardlike; no palatine teeth. Preoperculum wide. Five branchiostegals. Dorsal deeply notched; denticulated pharyngeals. No armature on the gill-covers or preoperculum; no accessory gills.

Genus XIII. Aphareus, Cuv. A genus of uncertain affinities, and placed by the authors of the Histoire des Poissons, after the Menidae, merely because no more fitting position occurred to them. They were acquainted only with a dried specimen which seemed to have some resemblance to Cassio, but differed from it in having an obtuse gill-cover and large mouth with an elevated ray at the ends of the dorsal and anal fins. A very narrow band of villiform teeth on the jaws. Palate smooth, but the vomer projecting and producing two rounded eminences. No scales on the forehead, the lips, or jaws; but the cheeks, gill-cover, and top of the head scaly. Seven branchiostegals. Supraoccipital denticulated. Ventra attached a little behind the base of the pectorals. One species.

Genus XIV. Chetopterus, Schleg. Comes nigh to Aphareus in habit, but is furnished with vomerine teeth, and possesses four branchiostegals.

Family XI.—Pseudochromide, Mull. and Troesch.

Scaly fishes. Dorsal fin long. Jaw and palatine teeth; no armature of the opercular bones; interrupted lateral line; double under pharyngeals and hackle-formed pharyngeal teeth. Six branchiostegals; pectinated accessory gills.

Genus I. Cichlora, Mull. and Troesch. Generic characters of Pseudochromide, only the card-like (or hackle-formed) teeth of the palatines are wanting; there is a row of vomerine teeth. The stomach is sacal, the sacal part short; pancreatic caeca absent; swim-bladder present.

Genus II. Plesios, Cuv. Aspect of Chromis. Eyes approximated. Ventra very long.

Genus III. Pseudochromis, Rupp.

Labyrinthibranchs.

The peculiar structure of the pharyngeals in this family, by which a quantity of water can be retained in their complicated folds, is compared by Cuvier to the leaflets of a camel's paunch. The apparatus is covered by convex gill-covers that fit closely to the shoulders; so that even when the fish is out of the water the inclosed liquid cannot eva- The license to exhibit fish-fights is farmed, and brings a considerable annual revenue to the King of Siam. The species abounds in the rivulets at the foot of the hills of Penang. The inhabitants name it *Pla kat*, or the "Fighting-fish;" but the kind kept specially for fighting is an artificial variety cultivated for the purpose" (Cantor). The *Trichopodus trichopterus* is also very pugnacious; and the exquisite beauty of its varying iridescent metallic tints make it a great acquisition to garden tanks. The *Tr. nobilis* inhabits the rivers of Sikkim, in northern Bengal.

The *Oxyphromenus olfax* is well known in Batavia under the name of *Gourami*, for its excellent flavour when brought to table. It attains the size of a large Turbot, and Commeron relates that he had never eaten anything more savoury and delicious, neither among fresh-water fish nor among marine ones. He adds, that the Dutch residents in Java rear this fish in large jars, renewing the water daily, and feeding it wholly on river plants, especially the *Pistia natans*. But M. Dupetit-Thouars declares that he saw those kept in a stew crowding to the mouth of a drain to feed on human excrement. The *Ophiocarpi* are very tenacious of life, and the Chinese bring them to market yet alive, though their entrails have been removed, and sell them in slices. When the irritability of the flesh is so much exhausted that it no longer quivers under the knife, its value is greatly depreciated. This Chinese practice, however much it may shock the feelings when described, is not worse than the crimping of Cod on the London fish-stalls. The *Ophiocarpi marginatus*, Cuv. (*gachus* of Buchanan) is often seen travelling among wet grass in the beginning of the rainy season.

**Family XII.—Labyrinthibranchidae.**

*Poeciliopsidae pharyngeus labyrinthiformis*, Cuvier; *Labyrinthichthys chui*, Owen; *Anabatidae*, Cantor. Upper pharyngeal bones furnished with leaf-like folds, including cavities capable of retaining water. Gill-covers convex, and fitting tightly to the shoulder. Scales large, those on the head scarcely inferior in size to those on the body. Body in most rather elongated, in some an oblong oval. Mouth, cleft past the eye in one genus only, in most little more than half way to the eye, in all terminal. Gill-membrane generally shut up under the scales. Ventral sometimes without a spine, of from one to five or six soft rays, generally under the pectorals, sometimes farther forward. Lateral line interrupted or continuous, curved, deflexed, or straight. ANALYTICAL TABLE OF THE ANABASIDÆ (Dum.)

Classification—Acanthopterous Fishes.

Fin-rays much prolonged. In the ventraals only. A solitary one. Dorsal long .................................................. TRICHOCEPS Dorsal long .................................................. COLIBA Several, one of them very long ............................................. OPHIOPHENGUS In all the fins, except the pectorals ........................................... MACROPODUS Fin-rays not elongated. Palate toothless. Opercularia and subopercula acutely toothed ANABAS Opercularia and subopercula not toothed. Teeth on the lips .................................................. HELOSTOMA Teeth on the jaws .................................................. POLYACANTHUS Teeth on the palate .................................................. POLYACANTHUS Dorsal with spinous rays .................................................. SPINOBRANCHUS 10. Dorsal without spinous rays .................................................. OPHICHEPHALUS 11.

GENUS I. ANABAS, Cuv. Preorbital, operculum, suboperculum, and interoperculum serrated, or strongly denticulated; preoperculum smooth-edged and not visible, being covered with the suborbital scales. Form anteriorly elliptical. Mouth small, terminal. Maxillary slender, and retiring under the narrow serrated preorbital; the rest of the suborbital, large and flat, cover the cheek, temples, and preoperculum. Many pores on the head and mandible. Villiform teeth on the jaws, the outer ones a little stronger; in front of the vomer or on the palatines, but far back on the vomer among the three upper pharyngeals, there is a group of teeth; pharyngeal teeth crowded, conical, and pretty large. Branchiostegals six. Dorsal and anal nearly of equal height throughout. Lateral line broken under the last two dorsal spines, recommencing two scales lower. Scales large, hard, and strong. Stomach small; pancreatic exca few; air-bladder forked behind, its points filling recesses on the sides of the tail. Two supplementary upper pharyngeals, complicated for holding water. One species.

GENUS II. HELOSTOMA, Kuhl and Van Hass. Mouth small, compressed, and protrusible, seeming to issue from, and recede under the preorbital. Teeth seated in the lips. Branchiostegals five. Pharyngeal complications very curious.

GENUS III. POLYACANTHUS, Kuhl and Van Hass. Named because of the presence of dorsal and anal spines. Distinguished from Helostoma by the jaws being armed with teeth; from Anabas by the absence of denticulations on the operculum; and from Coliba by the existence of five soft rays in the ventrales. Stomach small, excal, placed vertically across the long axis of the fish; pyloric caeca two; air-bladder of moderate size. Three species.

GENUS IV. CTENOPOMA, Pet. Gill-cover with two crescentic notches, and three pectinated toothed lobes. Teeth on the vomer and palatines. Many spines in the dorsal and anal fins.

GENUS V. BETTA, Bleek. Teeth on the premaxillaries, maxillaries, and mandible. Palate smooth; mouth small. Opercular pieces and suborbital scale-plates serrated; branchiostegals denticulated. Branchiostegals six. A small spine in the dorsal, anal, and ventral; the other rays joined, and flexible; short dorsal opposed to the long anal; ventrales under the pectorals. Java, 1500 feet above the sea.

GENUS VI. COLIBA, Cuv. Body oblong, elliptical, compressed. Back and belly equally curved. Dorsal and anal long, the soft portions conical; ventrales before the pectorals, of one long, villiform, soft ray, without any membrane. Preorbital pectinately toothed. Anal situated before the middle of the fish. Branchiostegals five. Scales ciliated. Stomach small; intestinal canal rolled up in a spiral; two pancreatic caeca. Ten species.

GENUS VII. MACROPODUS, (Ctenophora, Middel.) Pharyngeal apparatus as in Colibas. Pectorals five. Anal long; its soft part and the dorsal also ending in a long tapering point; ventrales consisting of a spine and five articulated rays, the first a long simple filament, the others branched. Branchiostegals four. Two species.

GENUS VIII. OPHIOPHENGUS, Comm. Distinguished from Polyacanthus and Coliba, chiefly by the shortness of the dorsal and the more complicated upper pharyngeal leaflets. Ventrales situated a little behind the pectorals, of a moderate spine, and five articulated rays, the first of which is simple and very long. Branchiostegals six. Stomach cecal, shaped like a retort; pancreatic caeca two, preoral; air-bladder simple. Three species.

GENUS IX. TACHYSURUS, Lacép. (Trichopogon, Schmidt.) Differs from Ophionemus in having a more convex profile, and an abbreviated dorsal of five spines instead. Lateral line having a slightly sigmoid curvature. Anal long, with many small scales along its base; five ventral rays, one elongated. One species.

GENUS X. SPINOBRANCHUS, Cuv. The labyrinthiform pharyngeals less complicated than in other genera; approaching Anabas in form, and in the comparative fowness of the anal spines, but leading to Ophicephalus by its possessing palatine teeth. Stomach cecal; two pancreatic caeca; no air-bladder. One species.

GENUS XI. OPHICEPHALUS, Bleek. Resembles a snake somewhat in their elongation, and in their depressed but rounded head being covered by large scales. Acanthopterygians merely in having an anal spine, the other fins being destitute of spinous rays. They are distinguished from other Acanthopterygian fish with thoracic ventrales in the cranium and face being covered, as in the Macrodus and Anabas, with polygonal scales or plates. Body elongated, nearly cylindrical anteriorly, somewhat compressed posteriorly. Head more or less depressed, a little wider than the body. Dorsal extending far along the back; caudal rounded. Lateral line continuous. Jaws, vomer, and palatines furnished with villiform or card-like teeth, some of them longer than others. Branchiostegals five. Ventrales with a spine and five soft rays. Stomach cecal, long, and obtuse; intestines rather short; pancreatic caeca two. Twenty species.

MUGIL FAMILY.

The English name of Mullet, applied both to the Mulli and Mugiles, is apt to occasion some misapprehension; and we have therefore, in our notice of the Mullidae, spoken of them always as Surmullets, an appellation hitherto proper to one species only. The two French names of Mugles and Mullies are not so liable to be confounded. Cuvier traces the name from the Spanish Mugel, where the g sounds in the Castilian dialect like the Scottish or Irish aspirated h. This is softened on the shores of Biscay to Mouille, whence the English Mullet. They are mentioned by Aristotle and others of the ancient authors by the names of Chalones or Chelones, Myxos, Kephalos, Sphenicus, and Kestreus. Cefalo remains in use at Naples to designate a species. There has been much confusion among British ichthyologists with respect to the proper application of the specific names to the species that frequent the British seas, but Mr Yarrell has thrown a flood of light on the obscurity by his excellent figures. Mr Yarrell, say the authors of the Histoire des Poissons, has given a charming figure of our Capitons (Mugil capitos, Cuv.) on page 200 of his first volume, under the name of the Grey Mullet; and at page 207 a figure not less good of Mugil chelo; and a third distinct species of a different aspect, named by him Mugil curtus.

The Mugil cephalus, or Mediterranean Grey Mullet, is distinguished from the English species by its eyes half covered by two adipose veils adherent one to the anterior and the other to the posterior margin of the orbit, and by the peculiar concealment of the maxillary bone, which, when the mouth is closed, is completely hidden beneath the preorbital. The base of the pectoral fin is surmounted by a long carinate scale. This is the best and largest of the Mediterranean kinds. It weighs about 10 or 12 lbs., and does not appear to have been yet detected in the seas or estuaries of Britain, nor along the oceanic shores of France. It is very common on the coast of Spain, especially around the island of Iviça, where the fishermen are said to recognise two varieties under the names of Mugil and Lisso. When surrounded by a net, it endeavours, and often successfully, to effect its escape, by leaping over the edges into the open sea.

Its hearing is very fine, as has been noticed by Aristotle, and it feeds on worms and small marine animals; but it is doubtful, though it has been advanced, that it can live on vegetable substances. It appears to be of a stupid character, a fact which was known in the time of Pliny, for that author tells us that there is something ludicrous in the disposition of the Mullets; for if they are afraid they conceal their heads, and thus imagine they are entirely withdrawn from the observation of their enemies.

When, towards the end of spring and the commencement of summer, the fishes of this species, excited by the necessity of living in the fresh water, approach the shores and advance towards the mouths of the rivers, they form such numerous troops that the water, through which they are seen without being clearly distinguished, appears to be bluish. This particularly happens in the Garonne and the Loire at these periods. The fishermen there adopt the plan of surrounding these legions of Mullets with nets, the inclosure of which they gradually contract, taking care to make a noise to frighten the fish and oblige them to press together, and heap themselves, as it were, one upon the other.

Of the Mullets thus taken, some are eaten fresh, others are salted and smoke-dried. It is with their eggs salted, washed, pressed, and dried, that the preparation called bo-taracha is made, which is a condiment greatly in request in Italy and the southern provinces of France. The flesh of this Mullet is tender, delicate, and of an agreeable flavour; it is fitter and more in estimation when it is taken in the fresh water. The ancients, who from the time of Aristotle were acquainted with this fish, had it in great request; and the consumption of it is still very considerable in most of the southern countries of Europe. According to the report of Athenaeus, those Mullets were formerly in very high esteem which were taken in the neighbourhood of Sinope and Abdera; while, as Paulus Jovius informs us, they were very little prized which had lived in the salt marsh of Oritiello in Tuscany, in the lagoons of Ferrara and Venice, in those of Padua and Chioggia, and such as came from the neighbourhood of Commachio and Ravenna. All these places, in fact, are marshy, and the streams by which they are watered are brackish, and communicate to the fish which they support the odour and the flavour of the mud."

A common mode of fishing in the sea for Mullet, practised at the present time on the shores of the Mediterranean, is to select a point of rock overhanging a considerable depth of clear still water. The fish are attracted to this place by being fed for some time with granulated macaroni, and then the fisherman in the gentlest manner lets down a small hook concealed in a pellet of paste and attached to a very fine line. Skill is exerted in withdrawing the fish, which is speedily hooked, without disturbing the others, but a practised fisher will soon obtain a good load. He must neither show himself nor permit his shadow to appear on the water.

In the Histoire des Poissons, Tetragonurus is placed at the end of the Mugilidae, with an intimation that the true place of the genus in the ichthyic scale has not yet been ascertained. We shall mention it again when we come to speak of the Notacanthide.

Family XIII.—MUGILIDÆ.

Mugiloides, Cuv. (Mugil, Linn.) Body cylindrical; back broad. Scales large, and extending to the head like those of the Opisthopteri. The dorsal widely separated, the first one having only four stiff, stout spines; when small in the adult males. Teeth, when present, so fine as to be almost invisible; maxillaries small, and mostly concealed by the thick premaxillary lip that presses against the preorbital when the mouth is shut. Mandible shrinking with a small symphysial cutaneous tubercle that fits a notch between the premaxillaries. Pharyngeals greatly developed, and closing the gullet so that only soft and thin matters can enter the narrow angular opening of the oesophagus. Branchiostegals four, five, or six, as in the Pharyngobranchii. Stomach caecula like a gizzard, with a thick muscular ascending branch.

Genus I. Mugil, Cuv. Abdominal Acanthopteri, with two widely separated dorsals. External aspect somewhat like that of a Danaus Chrysippus. Mouth small, with a transverse opening and a medial fold or crease on the under lip, which forms a corresponding notch in the upper one. Teeth exceedingly slender, often scarcely to be seen. Preorbital on the side of the snout finely pectinated, and receiving a slender maxillary more or less completely beneath it. Gill-cover large and convex, covering a complicated pharyngeal apparatus, which prevents any coarse matters from reaching the oesophagus, through the tortuous channel. Stomach gizzard-like; gut long and folded; pancreatic ceca few. Sixty species.

Genus II. Cestreaus, Cuv. Snout pointed. Mouth cleft longitudinally. Mandible short, without a medial tubercle, and toothless; rudimentary teeth concealed in the thick lip of the upper jaw; no teeth on the roof of the mouth. General form of Mugil, with four spinous rays in the first dorsal, but with the last ray of the second dorsal elongated. Teeth in a narrow band on the upper jaw only. Stomach caecal, large, not muscular like that of Mugil; two pancreatic ceca; air-bladder simple, with very thin coats. Two species. Celebes.

Genus III. Dajaus, Cuv. Snout projecting. Mouth a little more longitudinal than that of Mugil. No symphysial tubercle on the mandible. Villiform teeth on both jaws, the vomer, and palatines. Stomach less muscular than that of Mugil, the ascending branch being reduced to a tube, but little more fleshy than the caecal portion; intestinal canal doubled five times; two pancreatic ceca. One species, Jamaica and St Domingo.

Tasmannia, proposed by Cuvier, intermediate between Dajaus and Mugil, having the longitudinal mouth of the former, but the rough plates on the palate and tongue, which, unlike the Mugilis, have very little coarser than in that genus, and scarcely deserving the name of teeth. It is the Dajaus Bicrenatus (Rich.)

Genus IV. Nestus, Cuv. Form of a Cyprinoid Barbel. Head more compressed than that of Mugil; gill-covers flatter. Preorbital not covering the whole maxillary, which is not decurved so as to show itself below the mandible. Teeth on the two jaws, front of the vomer, and pharyngeals; none on the palatine bones. Lower lip very thick, doubled back, callous and trenchant. Stomach differing from that of Mugil in being wholly membranous and otherwise fleshy; intestine long, six times folded; pancreatic ceca two; air-bladder simple with thin coats. Two species.

ATHERINE FAMILY.

We are obliged, say the authors of the Histoire des Poissons, to leave isolated among the fishes a group composed of a single genus, which it is impossible to divide otherwise than into small tribes, and which does not associate closely with any other genus or family. Some species have teeth clearly visible on the jaws, vomer, and palatines, such as Atherina Boieri, and its allies, which have a large flat head; others, like A. saucelot have the teeth on the palatines so minute that they are barely perceptible; thirdly, there is a large number of extra-European species which have the roof of the mouth perfectly smooth and toothless; these are mostly American, and have a peculiar physiognomy resulting from the singular position of the pedicels of the premaxillaries and the curvature of the maxillaries. The latter bones are slender, and have a structure very uncommon among fishes, but which exists usually in the Mugil family, that is, to have the posterior end of the maxillary more slender than its anterior or articular end. Another affinity to Mugil may be found in the small number of rays in the spinous first dorsal, and in the abdominal position of the ventrals. We cannot, however, unite them to the Mugil family as Pallas advises, since none of the anatomical details which distinguish the Mullets from other fishes are found in the Atherrines. They have neither the notch between the upper lips, nor the symphysial prominence of the lower jaw; nor the pectinated denticulations of the preorbital; nor the unusual pharyngeal apparatus; nor the gizzard stomach. The premaxillary is much more protractile than with the Mullets, almost as much as in the Menoid Smaris. The teeth require to be examined through a lens to be properly seen, and the pharyngeals, which have the usual form of those of other fishes, are crowded with minute teeth.

The Atherines live in large shoals in all the localities that they frequent; and notwithstanding their small size, rarely more than six inches, they are esteemed as a delicate food. The young, for some time after they are hatched, cling together in dense masses, and in numbers almost incredible. These are taken and prepared in the lump by frying or by boiling in milk. The inhabitants of the Mediterranean coasts of France call these newly hatched Atherines nonnat (unborn). In some places the adult fish is so abundant that they are employed to feed animals; at Venice for instance, where they swarm by myriads in the canals that traverse that city, and are sold in the streets. Classification—Acanthopterous Fishes.

The family of Notacanthidae, says M. Müller, includes those Acanthopterids, with or without abdominal ventrals, which have many isolated dorsal spines, and the coracoid bones suspended to the vertebral column and not to the head. The same structure exists in Notacanthus as well as in Mastacembelus, but it still remains to be ascertained whether Tetragnomurus belongs to this group or not. There is little to add regarding the family to the facts collected in the table. The Notacanth or Campylodon of Otho Fabricius and Reinhardt is a Greenland species, and Bloch has been much blamed for describing it as an Indian fish; but the fact is, that a very similar species inhabits the Australian seas, and one of these may have come into Bloch's hands. Tetragnomurus Cuvieri of Risso, the only known species of the genus, inhabits great depths in the Mediterranean, and is consequently more rarely seen. It is named Courpata, has a black colour, and hard scales, deeply chiseled and ciliated. Its flesh is said to be poisonous. We have seen no specimen, but think from the structure assigned to the scales, that it should be compared with the Elopidae or Amiidae.

Family XV.—Notacanthide, Mull.

Scales cycloid, covering the head, body, and partially the fins. Snout prominent; mouth beneath, horizontal; nostrils near the eye. Branchiostegals seven or eight; gill-openings beneath, closed directly behind. Head slightly armed; opercular pieces nearly concealed by the integument. Body elongated, sword-shaped posteriorly. Spinous dorsal not continued by membrane; soft dorsal in some one or two rays, or altogether absent; in others of three rays. Coracoidei suspended to the vertebral column in the Eel, and not to the head as in most bony fishes. Ventrals abdominal, or pectoral; when present composed of a spine and eight soft rays. Stomach cecal; pancreatic exca few.

Genus I. Notacanthus, Bloch. Dorsal spines free, with a divided soft ray in the axilla of the last one; anterior anal spines detached, each with a low membrane; anal joined to a distinctly-formed caudal. Body much elongated, sword-shaped, and tapering posteriorly. Snout prominent, obtuse. Small cycloid scales covering all parts of the body, head, and face, except the lips. Abdominal ventrals of two spines and seven articulated rays, united on the basial line by membrane into one continuous fin. Branchiostegals short; the maxillary teeth small, closely set, and arranged in a free edge. No armature on the head except an acute spine issuing from the maxillary above its posterior extremity. Teeth slender, with lanceolate tips uniserial on the upper jaw, whose border is formed wholly by the premaxillaries; an internal concentric curve without a break is formed on the vomer and palatines by more subulate teeth, which in one species are pluriserial in front; the mandibular teeth are uniserial or pluriserial; all the teeth curve backwards. Two species, Greenland and Australia.

Genus II. Rhychochelodella, Bloch. Scolecoid. (Macromaculatus.) Body elongated, compressed; snout pointed, projecting; fleshly or membranous, visible and situated underneath, forming a proboscis used as an organ of touch. Branchiostegals seven; teeth mere sacralities on the premaxillaries, mandible, and fore end of the vomer. No armature on the head. Scales cycloid, covering the body, bases of the fins, gill-covers, cheeks, cranium, and borders of the eyes. Spinous dorsal not continued by membrane; soft one long and far back; anal corresponding to the soft dorsal, with two free spines in front. Stomach cecal, obtuse; two pancreatic exca; a long narrow air-bladder. One species.

Genus III. Mastacembelus, Kuhl and Van Hass. Elongated, but with a less elongated snout, which is merely conical and not striated beneath. Teeth rather stronger than in Rhychochelodella. A single spinous spine at the rounded corner of the preoperculum. Vertical fins in some species united, in others the caudal is merely contiguous to the other two. Ten species.

Genus IV. Tetragnomurus, Risso. Ventrals a little behind the pectorals. Body elongated, fusiform. Scolecoid obtuse. Mandible a little shorter than the premaxillaries. Upper lips thick, giving the face the aspect of Mugil. Teeth uniserial, conical, and a little recurved on the premaxillaries; mandibular teeth also uniserial, more curved, compressed and pointed posteriorly; vomerine teeth on the chevron and along the median line; tongue smooth; hyphryngal teeth in cardlike plates. No armature on the head. Body clothed in hard scales, lying in oblique rows, and exposing disks which are grooved. Genus Latodactyla, of the family of Ganocephalidae, to which genus this one has some other external similarity, especially in the remarkable character of two elevated scaly keels on the base of the caudal on each side. First dorsal composed of a series of very short spines, each with its membrane, which folds into a dorsal groove; soft dorsal more elevated, not long, opposite to an anal of similar height and shape. Stomach very long, cecal, conical; pyloric exca numerous, ranged along the sides of the ascending branch of the stomach, and along the duodenum; no air-bladder. One species. The proper place of this genus is undecided. M. Muller thinks it may be here.

Scomberoids.

In the periodicals of the day we read, that in 1855 the Herring-fishery of Scotland alone employed very nearly 70,000 people, made up as follows:—40,350 fishermen, 113 coopers, 21,832 women employed as cleaners and packers, 3,730 labourers, and 1,127 fish-curers. What the Herring-fishery is to the northern nations, the capture of the Scomberoids is to the maritime population of the Mediterranean, and to the Mackerel boats of the British Channel, and both sides of the Atlantic, down to the 30th parallel of latitude. The Tunny, Bonito, and Mackerel fisheries are known, by report at least, to all. These well known fishes, remark the authors of the Histoire des Poissons, are easily characterized, if we regard the typical forms only. In regard to them, the detachment of the posterior rays of the second dorsal would suffice, but these are merely the chiefs of numerous genera and sub-genera, in which the characteristic forms pass by insensible gradations into others which retain little of the primary types. Scales in general very small, and so thin, that they cause the greater part of the skin to appear quite smooth. Vertical fins without scales; gill-covers destitute of spines and denticulations. Numerous pancreatic exca;—and behold all is said that can be announced; yet a family aspect is recognisable in all, adhering to them in every modification, and we cannot subdivide them into separate families, but merely into groups of less value.

The following analytical table is not to be considered as separating the numerous genera into natural groups, but merely as a means of facilitating the labours of the student in discovering the generic name of any Scomberoid that he is investigating. The apodial Rhychochelodellus and Mastacembelus, and the abdominal Notacanthus, have been removed from the table as presented in the Histoire des Poissons, to form the family of Notacanthide. The fishery of the common Mackerel (Scomber scombrus) is described in detail, and with much accuracy, by Mr Yarrell, to whose pages we refer the reader, for we shall not now make lengthened quotations from a work which is in the hands of every one who is interested in British Ichthyology. We shall merely repeat from him, that on the 30th of June 1824, these fish were so abundant off Lowestoffe, that the catch on that day, by sixteen boats, amounted in value to L5252, and it is supposed that the owners and men concerned in the Mackerel fishery on the Sussex coast, realised altogether L14,000. The common Mackerel, though destitute of an air-bladder, takes a bait readily a few inches below the surface, and is a general inhabitant of all the northern seas, from Greenland and the Baltic, through the North Atlantic, to the Mediterranean, the Black Sea, and Sea of Azof. Very similar species exist in the Australian and Australasian Seas, the Cape of Good Hope, and Seas of China and Japan. Most of these have air-bladders.

The Tunny (Th. vulgaris, Cuv.; Scomber thynnus, Linn.), fig. 110, is one of the largest fishes of the ocean. When it weighs only a hundred pounds, the Sardinians give it the name of Scampirro, a diminutive derived from Scomber. When above that weight, and onwards to three hundred pounds, it is called Mezzo-tonno, or Half Tunny. The larger individuals frequently weigh a thousand pounds; and Cetti asserts that old males are taken occasionally weighing eighteen hundred pounds. The fishery of the Tunny dates from the most remote antiquity; and the city of Byzantium was more especially enriched by it. The shoals which entered the Bosphorus were said to meet near Chalcedon with a white rock, which so terrified them that they turned into the Gulf of Byzantium, now the port of Constantinople. It was, according to Cuvier, in consequence of this abundance of Tunneys, that the gulf in question received the name of the Golden Horn; and the oracle of Apollo designated Chalcedon as the City of the Blind, because its founders did not perceive the inferiority of its site in relation to these valued fish. Gibbon, however, tells us that "the curve which the gulf describes might be compared to the horn of a stag, or, as it should seem, with more propriety, to that of an ox. The epithet golden was expressive of the riches which every wind wafted from the most distant countries into the secure and capacious port of Constantinople." The same prodigious quantities of the Tunny are still seen there as in ancient times. According to Syllius, twenty vessels might be filled by a single cast of the net; and they might frequently be taken by the hand without the aid of nets. When ascending towards the port, they might be killed with stones; and even women took them in quantities, merely by suspending a large basket by a cord from the windows. The Tunny fishery was of still more ancient practice in the West. The Phoenicians established it at a very early period on the coasts of Spain, both within and beyond the columns of Hercules. It is thus that we find the Tunny on the Phoenician medals of Cadiz and Carteia. Its salted preparation was known to the Romans as an esteemed article, under the name of Saltamentum Sardicum. The Tunny fishery does not seem to be now car- ried on at Constantinople on a great or systematic scale, but is chiefly concentrated in the interior of the Mediterranean. The species sometimes wanders along the British shores; and a fine specimen, measuring 9 feet in length, was killed in the beautiful Gairloch, opposite Greenock, in July 1831. It is preserved in the Andersonian Museum, Glasgow.

The fish known to navigators under the name of Bonito belongs to our present genus. It is the *Th. pelamys* of Cuv., and sometimes occurs along the British shores. Resembling the Tunny in form, it is a great deal smaller, seldom exceeding the length of 30 inches, and is celebrated in the tropical seas for its eager pursuit of the Flying-fish. The Bonito of the Mediterranean, however, is the *Auxis vulgaris*.

It is a singular thing, as Cuvier has observed, that a fish so generally met with as the great *Lepidopus argyreus* of the European seas, so handsome, and so large, should have remained unknown to naturalists so recently as the end of the eighteenth century, and that it should have been afterwards successively described by various writers, under a new name, and by each in ignorance of the labours of his predecessor. If we figure to ourselves a large and broad ribbon of silver, swimming with a wavy motion through the water, and casting from it in its progress the most beautiful reflections of light, we may form some notion of the general aspect of this creature in its living state. Its length, as described by Montagu (under the name of *Zyphothecus tetradens*), was 5 feet 6 inches, with a depth at the gills of 4½ inches; it gradually decreased from the vent to the commencement of the anal fin, where it measured only 2 inches in depth; at the end of that fin the form was nearly round, and the diameter only half an inch. The weight, without the intestines, was about six pounds. Montagu's specimen was taken in Salcombe Harbour, on the coast of South Devon, on the 4th June 1808. It was swimming with astonishing velocity, *with its head above water*, going, as the fishermen said, "as swift as a bird," and was killed by the blow of an oar. It occurs occasionally on most of the European coasts; is more frequent in some parts of the Mediterranean; and has been captured as far south as the Cape of Good Hope.

The very singular form, *Nemichthys scolopaceus* (Rich.), captured in the Southern Atlantic by Mr. Adams, surgeon, H.M. ship Samarang, seems to be more nearly allied to *Trichiurus* than to any other genus, but as its internal structure has not been investigated, its proper position in the system must remain for the present doubtful. It is remarkable, above all other fishes, for the extreme length of its thread-like tail and long jaws, compared to its abbreviated body, many times shorter than the gape of the mouth. It is apodous, with the anus on the thorax, a range of spinous rays, each with a triangular membrane, not connected to the following one, running along the whole back, and a ventral equally long, but with taller simple flexible rays, and a more connected membrane. There is no caudal, though, as the tip of the tail was slightly damaged, this fact was not fully established. When newly caught the fish had a dull white colour, with brown spots. The editor of the *Archiv für Naturgeschichte* is inclined to place this fish among the Tunniidae, but it seems to us to associate better with *Trichiurus*, and we place it here without inquiring whether *Trichiurus* be a real Scomberoid or not.

*Nauacrates duxor*, the famous Pilot-fish of navigators (*Gasterosteus duxor*, Linn.), so named from its habit of keeping company with ships at sea, and frequently swimming beneath their bows. It would seem, from early indications of a similar instinct, to be the *Pomilus* of the ancients, described as pointing out the way to dubious or embarrassed sailors, and as announcing the vicinity of land by its sudden disappearance. It was thus regarded as a sacred fish. The other story of its serving as a guide to the Shark does not appear to have been transmitted to us from so remote a source. It is not mentioned even by the ichthyologists of the sixteenth century; and Cuvier regards as the first allusion to it, that of Dutertre in his *Description of the Antilles*, printed in 1667. Since that period it has been carefully repeated by all voyagers and compilers; and Osbeck even makes it a subject of pious reflection on the wonderful ways of Providence. We are told by a greater than Osbeck that "they that go down to the sea in ships, that do business in great waters; these see the works of the Lord, and his wonders in the deep;" but the fact in the present instance seems reducible to this, that the Pilot accompanies both ships and Sharks, sometimes swimming before, sometimes behind, for the sake of preying upon whatever may be thrown overboard in the one case, or left uneaten in the other. It is true that the Shark never attacks it; but it is also true that the hawk does not attack the swallow; and in both instances the reason is the same; the Pilot being too nimble for the unwieldy Shark in the water, just as the feebler but more agile bird is too swift in its movements for *falco* in the air. It is thus that the apparent alliance of these dissimilar fishes may be explained even upon general principles, to say nothing of Bosse's observation, who assures us that he has seen hundreds of Pilot-fish, that they always keep at a respectful distance from the Shark, and swim about swiftly in different directions, that they may more certainly avoid it. If any food be thrown overboard, the Pilot stops to seize it, and abandons both the Shark and vessel. Geoffroy no doubt tells a story of two Pilot-fish having been seen to take a great deal of trouble, swimming to and fro, in order to conduct a Shark towards a baited hook: but admitting the truth of the details, it is clear, that whatever advantage might eventually accrue to the conductors, the probable result to the Shark was a cruel death, and one is consequently the more inclined to admire how the narrative itself should find place in a Memoir sur l'affection mutuelle des quelques animaux! The Pilot-fish in question is chiefly a Mediterranean species, although it also spreads into distant oceans, having been found by Daldorf under the equator. A great extent of geographical distribution may indeed be expected in reference to a species which is said to suffer itself to be led away immense distances in its eager pursuit of ships. Dutertre records that he saw one which followed his vessel for more than 500 leagues. Whether he kept his eye upon it night and day during all that time, or in what other way he ascertained it to be the same individual throughout so long a traverse, is what he does not state, and we therefore cannot explain.

In further illustration of the subject, we shall subjoin a short extract from a recent publication, Dr Meyen's *Reise um die Erde*: "The Pilot swims constantly in front of the Shark; we ourselves have seen three instances in which the Shark was led by the Pilot. When the Sea-Angel neared the ship, the Pilot swam close to the snout, or near one of the breast fins of the animal; sometimes he darted Classification—Acanthopterous Fishes.

rapidly forwards or sideways, as if looking for something, and constantly went back again to the Shark. When we threw overboard a piece of bacon fastened on a great hook, the Shark was about twenty paces from the ship. With the quickness of lightning the Pilot came up, snelt at the dainty, and instantly swam back again to the Shark, swimming many times round his snout, and splashing, as if to give him exact information as to the bacon. The Shark now began to put himself in motion, the Pilot showing him the way, and in a moment he was fast upon the hook. Once we watched a Pilot for many days, who kept constantly swimming close before the keel of the ship. The sailors say, as of a thing well known and familiar, that such a fish so situated has lost his Shark, and is seeking another. Upon a later occasion, we observed two Pilots in sedulous attendance on a Blue Shark, which we caught in the Chinese Sea. It seems probable that the Pilot feeds on the Shark's excrements, keeps his company for that purpose, and directs his operations solely from this selfish view." The reviser of this article has seen many Sharks caught in the Bight of Benin. They were frequently accompanied by one or two Pilot-fish, pretty objects with their light-blue bands, more often by troops of the disgusting-looking Echeneis, and not seldom without either of these fishes. The Pilot-fish swam gracefully round the head of the fish, but quickly struck off on one side when the monster, urged by his voracious appetite, turned up to take the bait. This bait was approached both by the Pilot-fish and Remora—by the one with an easy and elegant motion, by the other with a wriggling of the taper tail that conveyed the notion of swimming with difficulty. It seemed to us that both these attendants had no other object than that of procuring food for themselves. The Remora very commonly deserted the Shark, even when it was not caught, and attached themselves to the ship's bottom, darting off when any greasy water was thrown overboard by the cook, to pick up the morsels of fat from the clear blue water, returning again to their resting-place to be borne through the water without trouble.

The generic term Coryphaena is derived from κορυφή, vertex, or top of the head, in reference to the height of the crest of the cranium. This division contains the famous Dolphin of the Mediterranean (Cor. hippurus, Linn.), so celebrated for the beauty of its versatile tints.

"Parting day Dies like the Dolphin, whom each pang imbues With a new colour as it gasps away, The last still loveliest, till—'tis gone—and all is gray."

The species are still in some measure indistinctly characterized. They occur in the Pacific and Atlantic Oceans, and the Mediterranean Sea, and are remarkable, among other things, for their keen pursuit of Flying-fish, which, in the first place, they force to leave their native element, and then following swiftly in a corresponding track, receive with open mouth the moment they descend exhausted to the surface. The Coryphaene may be regarded as among the most brilliant inhabitants of the sea. It is necessary, according to Bose, to have seen them following a vessel in troops, before we can form a proper estimate of their beauty. When they swim embodied near the surface, and beneath the light of a cloudless sky, they seem effulgent with the richest gold, combined with the sparkling lustre of the topaz, the emerald, and the sapphire,—and every brilliant hue in perpetual change, accordant with the vivacity and varied grace of their movements. It is indeed a spectacle sufficient anywhere to excite our unfeigned admiration; and when seen suddenly amid the waves of the lonely and monotonous ocean, it comes upon us like a glad surprise. The beauty of these fishes has in every age attracted the wonder

"Of all who on the wide deep wandering are;" and it is so far to be regretted, that their fugitive colours have been the chief object of attention,—their more precise description and specific discrimination having been greatly disregarded.

The Coryphaene are strong, active, and voracious fishes. While swimming rapidly, they seem rather as if impelled or projected forwards by some exterior force, than by any exertion of their own. But, on attentive examination, a strong and rapid muscular movement may be detected by the constant undulation of the long dorsal fin, a movement which greatly contributes to the throwing off of those lustrous metallic reflections for which they have so long been noted. The Mediterranean species, Cor. hippurus, if not the most beautiful, is the largest known. It sometimes attains to the length of five feet. Its colours, so far as they are capable of description, are silvery blue above, with markings of a deeper azure, and reflections of pure gold—the lower parts citron yellow, marked with pale blue. The pectoral fins are partly lead colour, partly yellow; the ventrals are yellow on their under surface, and black above; the anal fin is yellow. The iris of the eye is made of apparent gold. This description is from the recorded observation of the living fish by M. Biberon. Another eye-witness, Colonel Bory St Vincent, describes the back as being of a sea-green colour, sprinkled with orange spots; the abdomen silvery; the lateral line yellow; the dorsal fin celestial blue, with golden-coloured rays; the caudal fin surrounded by a green hue; the other fins yellow.

One or two other kinds, not so distinctly known, occur in the Mediterranean, and many others in more distant seas. The Portuguese name more than one species Dorade, a term which, from its similarity to Daurade (a frequent appellation of our Gilt-head, Chrysophrys aurata), has produced some confusion. Not less ambiguous is the name of Dolphin, which appears to have been first misapplied to the Coryphaene by the Dutch. It is scarcely necessary to observe, that the English word Dolphin, as synonymous with the Greek Δελφίς, the Latin Delphimus, and the French Dauphin, was originally, and is still correctly, applied only to designate a group of cetaceous animals (allied in structure to the Whales), to which the classical Dolphin of antiquity assuredly belonged. But by some conversion, into the history of which it is not worth while to inquire, the term has been applied by most modern writers, particularly poets, to a creature of another class, a genuine fish, of the genus Coryphaena. No fault, therefore, can be imputed to the naturalist, if the general misapplication of the term is now found to occasion any misconception. There is no doubt, however, that the animal beloved by gods and men, the Hieros Ichthys of the heroic Greeks, and the revered symbol of the Delphic Apollo, was nothing more than a Pellock or Porpoise.

Xiphias (Sword-fish), though by no means uncommon, are seldom captured, owing to their extreme vigilance. Cap-

tain Beechy informs us, that while in the Pacific Ocean, near Easter Island, "as the line was hauling in, a large Sword-fish bit at the tin case which contained our thermometer, but fortunately failed in carrying it off." Their mode of capture in the Mediterranean may be likened to Whale-fishing in miniature, and is said to be a very amusing and exciting sport. A watchman placed upon a mast, or standing on the summit of a neighbouring rock, gives warning by signal when he sees a fish approach. The fishermen then row towards it; and, being so skilful as frequently to strike the fish from a great distance, they throw a harpoon into it attached to a long line. An arduous struggle then commences, during which the aggressors are sometimes pulled about by the fish for many hours before they can get it into the boat. The sword-like prolongation of the snout in *Xiphias* is formed of the condylent premaxillaries, firmly and immovably articulated with the prenasal and maxillary bones as in the *Scomberesox*.

![Fig. III. Histiocephalus paleothenus.]

We cannot give more space to the more remarkable forms of this large and important family of fishes. The peculiarities of their structure, such as the loose texture of their bones, the glandular-like assemblages of pancreatic cæca which they possess, and the papery-like scales, scarcely to be distinguished from the smooth skin, with the neat tapering tail and large crescentic caudal, together with the delicacy of the cutaneous fold or membrane, in which the other two vertical fins are developed, and which, from its early disappearance, leaves many of the rays detached in form of finlets, are all prominent characters of the more typical species, and give such an unity of aspect to the whole group, that it might rank as an order, and not as a mere family division. The family is generally distributed in all districts of the ocean, and the *Temnodon solitarius* is especially a cosmopolitan fish, being found in all the temperate and warmer districts of the Atlantic and Pacific Oceans.

In concluding, we must express our regret that M. Valenciennes should have adopted the word *Rhombus*, first used by Lacepède to distinguish a Scomberoid genus, but which has been generally employed by ichthyologists to designate the Turbots among the *Pleuronectidae*. Cuvier had given the Scomberoid genus the name of *Peprilus* in the second edition of the *Regne Animal*, and this being also a Lacépéedian name of this genus, the continuance of it would have avoided the mistakes that are likely to arise from two very different genera retaining the same appellation.

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**Family XVI.—Scomberideæ**

Scales generally small, tender, smooth, seldom extending to the vertical fins; bones less solid than in most other osseous fishes. Tail and caudal fin, generally, very vigorous. Pancreatic cæca numerous, and frequently united in bunches. No armature on the opercular pieces. In many, the sides of the tail are keeled and armed with keeled, often acute scales. The posterior rays of the second dorsal and anal are often detached from the rest of the fin. Sometimes the spines of the first dorsal are not connected by membrane. The front anal spines are detached in most; the caudal is very frequently large. These characters are variously combined, none being common to all, but they serve to divide this numerous family into tribes.

**Tribe I.—Finlets, and no Armature on the Lateral Line.**

First dorsal continuous, the rays of the second detached, forming finlets. Body fusiform. Caudal large and vigorous. Tail becoming very slender, and more or less keeled. In some there is an interval between the first and second dorsal, in others these fins are contiguous; in some the scales of the thorax are large, forming a corset. Most, or all, have seven branchiostegals.

**Genus I. Scomber**, Linn. Detached finlets behind the dorsal and anal; a large interval between the dorsals. Tail with a slight ridge on each side, but no acute keel. Generally an air-bladder, though in some species that organ is absent. Fourteen species.

**Genus II. Thyrsus**, Cuv. Mackerels, but with contiguous dorsals; the scales of the thorax larger and stronger, forming a corset which ends posteriorly in pointed spines; finlets more numerous; no free space in front of the dorsal. An air-bladder, a pharyngeal projection on the lateral caudal ridge. Thirteen species.

**Genus III. Auxis**, Cuv. Dorsals separated by an interval. Tail keeled on the sides; intermediate between, and connecting the Mackerels, having widely separated dorsals, to the Tunnies and Bonitos, with small teeth, numerous finlets, keeled tail, and contiguous dorsals. Three species.

**Genus IV. Pelamys**, Cuv. Differs from Auxis in having contiguous dorsals and strong pointed teeth, standing rather widely. Two species.

**Genus V. Cyphus**, Cuv. No corset. Compressed lance-pointed tranchet teeth. Detached finlets and long first dorsal of Thyrsus. Elongated body, keeled tail, and pectoral cuirass; this last character distinguishing them from Pelamys. Very short uroform teeth on the chasms of the vomer, palatines, tongues, and branchial arches. Sixteen species.

**Genus VI. Thyseites**, Cuv. No lateral caudal keel; no pectoral corset. First dorsal contiguous to the second. Body elongated, much compressed. Small but perfect ventrals. Teeth pointed, compressed, tranchet; longer and stronger anterior premaxillary teeth; palatine teeth small, pointed. Four species.

**Genus VII. Gemphus**, Cuv. Thyseites with rudimentary ventrals. No palatine teeth. Two species.

**Genus VIII. Rovettus**, Bonap. (*Rovetta*, Cocco; *Tetragnathus*, Lowe; *Aphorus*, Isid.) Body elongated, compressed. Head covered with a scaly or leathery skin. Belly keeled on the ventral edge. Gill-complex without a lateral keel. Head unarmed; mouth somewhat oblique. Gill-openings very wide. Mandible shorter than the premaxillaries. A row of equidistant conical, slightly recurved, serrated teeth on the jaws; some of them long, especially the premaxillary ones near the symphyses, which are the longest; a unilateral range of smaller ones on the vomer and palatines. Two dorsals, with finlets above and below the tail. Caudal forked. Branchiostegals seven. Many pancreatic cæca; small air-bladder. One species.

**Appendix to Tribe I.**

**Genus IX. Lepidopus**, Cuv. (*Aplodactylus*, Lowe.) Form of Gemphus and Thyseites, even more elongated; but they have no soft dorsal or finlets, the spinous rays running all along the back. Vestiges of ventrals in form of a little squamoid appendage, with the styloid public bone felt through the skin. Teeth like those of Thyseites on the jaws; none on the vomer, and very fine ones on the palatines. Branchiostegals six. A long caecal stomach; twenty-three pancreatic cæca; air-bladder long and narrow. One species.

**Genus X. Trichiurus**, Linn. Head, body, and dentition of Lepidopus, but without a vestige of ventrals. The dorsal, also, is spinous throughout like that of Lepidopus; while the anal consists of a series of spines that scarcely protrude through the skin, and the tail ends in a filiform point without a caudal fin. Four species.

**Genus XI. Nemichthys**, Rich. (Fey. of the Salpther, pl. X., 1848.) Form greatly elongated, and tapering posteriorly into an exceedingly long filamentous-looking tail. Head longer than the body, excluding the tail. No ventrals. Elongated jaws formed as in Scomberoides; the edge of the maxillary touching the angle of the long gape of the mouth, which is bounded by the very slender premaxillaries and mandible. Branchiostegals nine or ten, as fine as a hair. Anal between the small pectorals. Eye large. Dorsal spines isolated, each with a membrane in its axilla, extending from the occiput to very near the point of the tail, where they can no longer be traced for their minuteness; anal fin with more numerous and taller spines, and apparently a continuous membrane, disappearing also near the hair-like point of the tail; no caudal. None of the spines strong enough to be pungent, but none of them jointed. Teeth arranged in very close, fine, file-like bands, on the premaxillaries and mandibles; individually, when viewed through a lens, they appear to be semi-lanceolate with the points turned backwards. One species.

Group of Sword-fish. Muzzle in form of a sword or dagger. No detached finlets.

Genus XII. Xiphias, Linn. Allied to Thysan by their very small scales; the keels on the side of the tail, and interior organization. Their distinctive character is the elongation of the beak, composed chiefly of the premaxillaries and vomer, supported at the base by the frenum, nasal, and maxillaries, and which is a great offensive weapon. Their branchial laminae are peculiarly formed. The caudal, having the distinctive form of the family, is a powerful instrument of natation. No ventrals. Branchiostegals seven. Stomach cecal, conical; pancreatic ceca numerous; air-bladder large. Though the difference between these and Scomberoides and Nemichthys is so vast, as respects size, they seem with regard to the structure of the jaws to bear much the same relation to that small fish that Hemiramphus does to Scomberoides. One species.

Genus XIII. Tetrapurus, Rafin. Scomberoids with elongated and pointed bill as in Xiphias, but which have ventrals, and instead of a keel on each side of the tail, have little crests as in Scomber. Two species.

Genus XIV. Marahira, Lacép. With the pointed bill and the small lateral caudal crests of Tetrapurus, but without ventrals. One species.

Genus XV. Histiopterus, Lacép. (Notesthes, Herm.) Approaches nearly to Xiphias. The bill, and lateral caudal crests of Tetrapurus, but the dorsal is very high; and their long slender ventrals are composed of two rays. Branchiostegals seven. Stomach cecal, a great bag as long as the abdomen; ceca in a mass like a pancreas. Five species.

Tribe II.—Centreonott, Lacép. Scomberoids, with the first dorsal composed of isolated spines.

(i.e., No continuous membrane to the spines dorsal; with or without finlets behind the articulated dorsal or anal; and the lateral caudal keel present in some genera, wanting in others. Ventrals present in almost all.

Genus XVI. Nauchates, Cuv. A fusiform body, small uniform scales, and a keel on the side of the tail as in Thysan. Two free spines before the anal, and the above characters of the tribe. Four species.

Genus XVII. Elevate, Cuv. Nemoctes, except that the two spines before the anal are wanting, also the lateral caudal keel. The head, moreover, is depressed. Five species.

Genus XVIII. Lichia, Cuv. Body oblong, compressed, without keel or lateral ridges along the tail. Dorsal spines isolated, with each a membrane in its axilla, and a documbent spine in front of all. Four species.

Genus XIX. Pardopsis, Jen. Differs from Lichia in the total want of ventrals.

Genus XX. Chorinemas, Cuv. (Scomberoides, Lacép.) Lichia with the rays of the second dorsal or of the anal either wholly isolated or connected by a low membrane so tender that it disappears easily. Branchiostegals seven or eight, in some only four or five. Sixteen species.

Genus XXI. Trachinotus, Cuv. Differs from Lichia in having a more elevated body, and steeper profile before the eye, and in the anal and dorsal being more acutely falciform anteriorly. Some American species have the lower bodies of Lichia, and differ from that genus chiefly in the short, almost truncated snout. Twenty-four species.

Genus XXII. Apolegus, Cuv. Trachinoti with ventrals attached to the throat. One species.

Genus XXIII. Palmarus, De Kay. Rays of the dorsal not free, but connected by a low membrane; a spine before the anal.

Preoperculum and operculum serrated. The last-mentioned character seems to remove this fish from the Scomberoides, with which, however, its entire habit accords. One species (Trachinotus urgentus, Storer).

Tribe III.—Scomberoides, with a cuirassed lateral line; the scaly shields being themselves keeled and acute. This kind of armour becomes feebler in certain genera, so that it would not be noticed but for the smallness of the other scales.

Genus XXIV. Caranx, Cuv. Keeled scales on the lateral line strong and acute. Two separate dorsals. A couchant anterior spine; two free spines before the anal. No appearance of the corset of Thysan. Posterior dorsal and anal rays sometimes very slightly connected, or even forming detached finlets. Seventy-one species described in the Histoire des Poissons, and there divided into—

Trachinoti, which have the whole lateral line strongly cuirassed. Caranx, with only the posterior part of the line cuirassed. Body lanceolate. Finlets.

Carangus, low backers, low bodies, profiles nearly straight, and no finlets.

Citha, Carangii, with the tips of the dorsal and anal much prolonged.

Bleeker subdivides the genus into—Megalops, equivalent nearly to Caranx; Decapterus, of which C. kuroa is a type; and Caranx, the type of which is C. jerra.

Genus XXV. Carangichthys, Bleek. Premaxillary and mandibular teeth pluriserial; those forming the external row longer, with some canines in front of the mandible; teeth on the vomer, palatine, and tongue. Preoperculum denticulated. Lateral line armed with spinous shields. Branchiostegals seven. Kema.

The genus Caranx is succeeded naturally by small groups of Scomberoids, having a compressed body and an elevated trenchant profile leading up to a keel, in which this compression and elevation are at a maximum. In these the keeled scales of the lateral line are comparatively feeble.

Genus XXVI. Olisth, Cuv. Resemble the Citha in their falciform acute dorsals and anals, and have in addition the middle rays of the dorsal and anal prolonged into long, simple, articulated filaments. Two species.

Genus XXVII. Syrus, Cuv. Citha, with high trenchant profiles. The first or spinous dorsal concealed beneath the integuments; its spines lying against the internurals. Anterior soft rays both of the dorsal and anal prolonged. Two species.

Genus XXVIII. Blepharis, Cuv. Rhomboidal form. Spines of first dorsal very short; anterior rays of soft dorsal, and corresponding ones of the anal, prolonged into unbranched articulated filaments; long ventrals. A convex trenchant profile of moderate height. Three species.

Genus XXIX. Gallichthys, Cuv. Differs from Blepharis in having a higher profile, convex forehead, and vertical face. Body compressed, high. Ventrals long; caudal forked; first dorsal very low, in some reduced to a series of very short spines; anterior rays of the second dorsal and of the anal prolonged. Three species.

Genus XXX. Argyropelecus, Lacép. Profile descending in an oblique straight line from the occiput; not gibbous on the forehead. The dorsal line between the nape and the second dorsal, instead of ascending, like that of Gallichthys, is almost horizontal, and on its posterior half it supports the first dorsal; the general form is therefore less rhomboidal. Ventral, second ray of the first dorsal, and anterior part of the second dorsal and anal, long and pointed. Two species.

Genus XXXI. Pomera, Cuv. Oval form, but the gibbous profile of the forehead over the eye projects out of the oval, and the face is rather concave. From the forehead to the second dorsal the back is but slightly convex, being almost horizontal. The ventral curve is part of a regular ellipse. First dorsal very low and weak, and its posterior spines not connected by membrane; second dorsal and anal prolonged into falciform. One species.

Genus XXXII. Hypnus, Cuv. Like Pomera, but without a vestige of the first dorsal. Branchiostegals eight. Differs much from Pomera in its skeleton. Stomach simple, the pylorus being at the point of a dilated, compressed, triangular sac; pancreatic ceca numerous; very large air-bladder prolonged into two conical processes, one on each side of the tail. One species.

Tribe IV.—Scomberoids, having no detached finlets, no isolated dorsal spines, and no lateral armature of the tail; divided into genera having two dorsals, and those which have only one. (a.) Two dorsals.

Genus XXXIII. Seriola, Cuv. Differs from Caranx in wanting the armature of the lateral line, and from Lichia in the dorsal spines are alike remarkable for their singular forms and splendid colours.

The seas of the torrid zone have indeed no cause to envy the productions of those famous lands, the shores of which they have so long bathed with their translucent waters. If the equatorial regions of Africa and America possess, among their feathered tribes, the brilliant Soulimangas, the lustrous Humming-birds, and the gorgeous Chatterers, the intermediate ocean and the Indian seas contain countless thousands of the finny race which surpass even these in splendour. The Chatodonts, in particular, form a family on which nature has bestowed her ornaments with a lavish hand. The deep purple of the iris, the paler richness of the rose, the azure blue of the crystalline sky, the darkest velvet black, and deepest violet tint of the pansy, are seen combined with metallic radiance on the pearly bodies of this resplendent group. The eye of man receives the greater pleasure from their contemplation, in that, being of moderate or small size, and haunting habitually the coral basins of the transparent tropical seas, they disport themselves in the beams of a vertical sun, as if desirous of exhibiting their splendid liveries to the greatest advantage in the blaze of day.

### TABLE OF GENERA.

**No palatine teeth.**

Brush-like teeth on both jaws. Tribe I.

*Properculum not spinous.*

Dorsal single, wholly scaly.

None of the dorsal spines ending in filaments.

**Chatodon, Chelmon.**

Some of the dorsal spines with filamentous tips.

**Heniochus, Zanclus.**

Dorsals two, the soft one alone scaly.

Three anal spines; scales large.

**Ephippus, Dippane.**

Four anal spines; scales small, imbedded.

**Scatophagus.**

Dorsal merely notched.

**Taurichthys.**

*Properculum bearing a strong spine.*

**Holocanthus, Pomacanthus.**

Exterior teeth tricuspid; interior ones villiform.

**Platax.**

Fine and short villiform teeth on the jaws.

**Pettus.**

Palatine teeth present.

Trenchant teeth on both jaws. Tribe II.

**Pimelepterus, Dipterodon.**

Card-like teeth on both jaws. Tribe III.

**Beama.**

Villiform teeth.

**Pempheris, Toxodon.**

These genera are placed in tribes in the *Histoire des Poissons*. The first tribe being the Squamipennes with brush-like teeth, forming the Linnaean genus *Chatodon*, whose name is framed to describe this kind of dentition, in which the individual teeth are longer and stouter than villiform teeth, and resemble the strong bristles of a clothes-brush. In fig. 53 the coarse brush-like teeth of *Histiopterus recurvirostris* are well shown. The tissue of the teeth of most Chatodonts is albuminous, they have a yellowish colour, and are flexible and elastic, but when dry easily broken.

When once a person has seen several typical fishes of this group, he readily recognises the family character. The dense scaliness of the fins, which gradually taper out of the thickness of the body, so that one cannot tell without dissection where the one ends and the other begins, is very different from the small scales which creep on the membrane or rays of the vertical fins of some Scienoids, as *Nebrius, Lepiotes*, &c., and these never have the flexible, bristle-formed teeth of horny texture with which the true Chatodonts are furnished; and, moreover, show more or less of the muciferous development of the bones of the head and face characteristic of Scienoids, giving them their blunt facial profile. The Haemulons come nearer to the Squamipennes, but the bases of their vertical fins are set on abruptly on the back and belly, and do not slope off into the sides. The Chatodonts of the Red Sea were known to the ancients. Ælian speaks of them under the name of *Citharodus*. None of the species come into the seas of Europe, except the *Brama Ralli*, which wanders occasionally to the coasts of England. The Chelmons are Chatodonts with a tubular prolongation of the premaxillary and mandible, in form of a long, slender snout.

The species here figured was unknown to the authors of the *Histoire des Poissons*, but its habits, from the great similarity of its conformation, may be considered as similar to that of the two species described in that work. *Chelmon rostratus*, or *encladus*, is an inhabitant of the sea and rivers of Java, and has the instinct of throwing a drop of water from its bill, so as to light upon any insect resting on a leaf or blade of grass near the stream, and thus make it fall that it may instantly dart upon it. This was observed recently by M. Reinwardt, and an account of the same import is contained in the *Philosophical Transactions* for 1764. The Chinese residing in Java keep this fish in jars, and tempt it to practise its peculiar art for their amusement, by placing an insect on a rod or thread within range of its shot.

*Zanclus cornutus* of Cuv. has become, on account probably of its singular form and horned front, an object almost of superstitious reverence among the fishermen of the Moluccas. It is alleged, that when they happen to capture one of this species, they immediately salute it by certain genuflexions, and then cast it into the sea. It is, however, an excellent table fish, which attains a weight of 15 lbs., and resembles the Turbot in flavour. It is rather widely diffused, occurring both in the Indian seas and Pacific Ocean.

Baron Cuvier has remarked, that among all the strange and fantastic fishes preserved in the representations of Ruyesh, Renard, and Valentyn, and which have so long excited the mistrust of naturalists, none seems more likely to provoke that feeling than the species which these writers designate by the Malay name of Skankarbaune, or Buffalo-fish; and yet it now turns out that none is more accordant with the truth of nature. Its sharp recurved horns, the protuberance above the head, the compressed and unequal spines, and the singular distribution of colour,—all exist in a species recently received from the Indian Archipelago. It has accordingly been named Taurichtys by Cuvier—the Greek translation of the Malay name. The species here figured is *T. varius*, which is from four to six inches long, with a height almost equal to its length.

The species of *Holocanthus* are remarkable for the great beauty and symmetrical distribution of their colours, and for their excellence as articles of food. They are numerous both in the Indian and American seas. One of the most celebrated for the splendour and singularity of its aspect is that named the *Emperor of Japan* by the Dutch, and the *Chetodon imperator* of Bloch, figured in many works. Its body is deep blue, traversed all over by about two and thirty narrow bands of orange yellow. The pectoral fins are black, and the entire tail bright yellow. It is a large fish of its kind, sometimes attaining the length of 15 inches, and, as an article of food, is one of the most esteemed of all the Indian species, resembling our own much-prized Salmon in flavour. Another and more recently discovered species is *H. semicircularis*, Cuv. It occurs both at Timor and New Ireland. Its colours are white and blue; its length from 4 to 5 inches. The inhabitants of Waigou call it *Mami*.

Many fish of this family are remarkable for bony enlargements of some part of their skeleton, very often of the interneural bones. In the *Ephippus gigas* the top of the skull is swelled out into a solid mass, which hangs forwards like the crest of a helmet, or like the skull of a Rhamphastos, and the interhaemal which supports the first two anal spines is also curiously swollen. *Platax arthriticus* is another member of the family which derives its name from these gout-like swellings of some of its bones. *Psettus argenteus* is a Chinese and Australian species, represented by fig. 116; and *Scatophagus multifasciatus* is another handsome fish of the southern seas.

The *Toxotes jaculator* (fig. 118) is a small Javanese species, measuring 6 or 7 inches in length, remarkable for possessing the same faculty as that mentioned in our notice of *Chelmon rostratus*. When it perceives a fly or other insect upon an aquatic plant, it dexterously drives it into the water by a shower of drops. Cuvier received a specimen from Batavia, the stomach of which was entirely filled with ants. This species has been erroneously multiplied in systematic works. It is twice described by Shaw under two different names (Scarus Schlosseri and Labrus faciatus), neither of which is the right one; and there is no doubt of its being identical with Hamilton Buchanan's Coius char- terus, a supposed new species from the Ganges. It seems pretty widely distributed throughout the Indian Archipelago, and is known to the Malays by the name of Javan-sunpit.

**Family XVIII.—CILIEFODONTIDAE, Boas.**

_Synapomorphies, Cuv._ The most apparent character of this family is the incrustation of the soft portions of the dorsal and anal fins, and often of the spinous parts also, with scales. Scales strongly ctenoid. Body generally greatly compressed. Intestines long, and pyloric caeca numerous. Dentition various, giving rise to generic subdivisions.

(a.) **Ciliefodontini**, Bonap. Brush-like teeth on the jaws, none on the palate.

**Genus I. Ciliefodon**, Linn. Preoperculum not spinous. Dorsal single, entirely scaly; no prolongations of its spinous rays, but the soft dorsal sometimes ending in a long filament. Muzzle comparatively short, but more or less projecting. Teeth like long bristles densely crowded. Pyloric caeca long, slender, and numerous; air-bladder simple. Compressed body, oval, or nearly orbicular. Tail short. Caudal transverse. Head small. Branchiostegals six. Spinous rays, in most twelve or thirteen in the dorsal, and three in the anal. Sixty-five species.

**Genus II. Chelmon**, Linn. _Chelodons_, with a long slender bill, formed by the elongation of the premaxillaries and mandible. Maxillary roundish. Mouth very narrow, at the end of the bill; teeth short, villiform. Body very high. Dorsal and anal high and scaly; caudal square. Scales large. Three species.

**Genus III. Megapodus**, Guich. Distinguished from Chelodon by a cluster of longer teeth, with hooked points, situated on the end of the mandible. Eight species.

**Genus IV. Henicichthys**, Cuv. No preopercular spines. Spinous rays of the single dorsal fin short graduated, the third or fourth one having a filamentous tip, like a whip-chong. Body covered with large scales. Branchiostegals five. Body obliquely rhomboidal, the apex of the soft anal and the filamentous dorsal spine being at opposite angles, and the mouth and soft dorsal forming the other two corners. Profile nearly vertical. Preoperculum serrated. Five species.

**Genus V. Zanclus**, Comm. No preopercular spines. The filiform-tipped spinous dorsal ray of Henicichthys, and nearly the same form of body, but the scales are extremely small. Muzzle more tubular and projecting, but not so much as in Chelodon. Posterior parts of the soft dorsal and anal low, with a straight inclined outline, so that the mouth and anus are the opposing angles of the rhomb; the other two being the long dorsal spine and apex of the soft anal, as in Henicichthys. Stomach local, of moderate capacity; fourteen to nineteen pancreatic caeca. Two species.

**Genus VI. Histiopterus**, Schleg. Resembling Henicichthys and Taurichtys in the form of the body. Dorsal fin very tall, with four strong spines, without scales. Cheeks scaly. Preoperculum, opercular, and top of the head and snout presenting the granulated surfaces of the bones. Snout more or less elongated and tubular, the elongation being chiefly in the nasal, vomer, and lower limb of the preoperculum and other bones supporting the jaws, which are at the extremity of the snout. Teeth coarsely bristle-formed, blunt, crowded, in a wide band on the jaws. Eye large. Three species.

**Genus VII. Ephippus**, Cuv. No preopercular spines. Dorsal deeply notched between the spinous and soft portions; the spinous part being destitute of scales, and capable of folding into a scaly furrow on the back as in the Scatophaga. Three anal spines. Body oval; or nearly orbicular. Ventral profile almost horizontal. Pectoral fins short. Branchiostegals six. Four species.

**Genus VIII. Drepane**, Cuv. Ephippus, with long pointed pectorals. Bodies high and more rhomboidal, the ventral profile descending to the soft anal. Branchiostegals six.

**Genus IX. Scatophagus**, Cuv. Dorsal deeply notched between the spinous and soft part. No preopercular spines; four anal spines. Scales small, lost in the epidermis, but ctenoid in structure. Body a broad oval. Tail between the vertical fins very short. Stomach simple; many pancreatic caeca; air-bladder simple, pretty large. Six species.

**Genus X. Tauchthythys**, Cuv. Dorsal less deeply notched. A protuberance on the occiput, and a horn opposite the middle of each orbit. Ventrais rather large. Form unevenly subrhomboidal, higher than long. The dorsal apex formed by the fourth or fifth spinous ray; second anal spine the largest. Preoperculum not spinous. Face concave. Two species.

**Genus XI. Holocanthus**, Lacép. Dorsal single, scarcely notched, or wholly even. A large spine at the angle of the preoperculum. Body a regular oval. Vertical fins all scaly. Border of the preoperculum generally serrated. Branchiostegals six. Twenty-six species.

**Genus XII. Pomacanthus**, Cuv. More elevated than Holocanthus, but still having a nearly oval form. Preoperculum and preoperculum always with entire edges, but with the strong spine at the angle of the latter. Dorsal spines generally fewer than in Holocanthus (nine, or rarely ten); anal spines three or more, deeply imbedded in front of the anal. Teeth furnished with two short lateral points, as in a few Holocanthus. Six species.

**Genus XIII. Platax**, Cuv. Setiform brush-like teeth, but in front of them a row of trenchant teeth triboliate at the points, as in a few Holocanthus, but more evident in the young fishes. Body very much compressed, and notched; that is, appears to graduate insensibly into the dorsal and anal, which taper to long points; the entire height of the fish much exceeding its length; these fins are scaly, and the spinous rays (which are few in the dorsal) are buried in their front edges. Ventrais long and pointed; caudal rounded. Branchiostegals six. Fourteen species.

**Genus XIV. Psettus**, Comm. Body compressed. Dorsal and anal scaly, with the points more or less falciform. Spines almost concealed; might form a group in the genus Chelodon; but the teeth are rather villiform than setiform. Ventrais reduced to a single spine, the short rays being obsolete. Branchiostegals six. Some are more elevated, and others more rounded or oval. Dorsal spines usually three, anal three.

**Genus XV. Hypsognathus**, Schleg. Ventrais close to the anus; soft dorsal low. Height of the body nearly equal to its length. Branchiostegals six.

**Tribe II.—Pimelepterini** (Bonap.) _Chatodontidae_, with palatine teeth and with trenchant teeth on the jaws.

**Genus XVI. Pimelepterus**, Lacép. (_Dipteronotus_ and _Xytrema_, Lacép.). Distinctive character, unibar teeth, each having a trenchant limb rising at a right angle from a horizontal heel. Body oblong. Head obtuse. Dorsal single. Fins thickish; the soft rays being densely covered with scales. General aspect much like that of _Crenidens_. Head scaly. Ten species.

**Genus XVII. Dipteronotus**, Cuv. Much like Pimelepterus, but the dorsal is deeply notched anterior to the soft rays, and the incisorial teeth want the bony heel. Branchiostegals six. One species.

**Tribe III.—Chatodontidae**, with villiform or card-like teeth on the jaws and palate. Included in Pimelepterini of Bonap.

**Genus XVIII. Brana**, Bloch, Schneider. Vertical fins covered with scales, the articulated dorsal occupying much of the back, and, as is usual in the family, higher in front, on the border of which three spinous rays are barred; becoming low posteriorly. Anal shorter, but similar in form. Mouth nearly vertical when closed. Teeth card-like on the jaws and palatines. Body compressed, ovate in outline, obtuse at the facial end, tapering into the tail. Snout very short and forming part of the obtuse profile. Branchiostegals seven. Stomach short; pancreatic caeca five. Three species.

**Genus XIX. Nemorhamphus**, Valenci. (_Polynemus_, Valenci.; _Lowe_). Body oblong, covered with very smooth scales. Head small, scaly. Snout not upturned. Mandible prolonged with two long symphysial bars. Teeth on the jaws, palatines, vomer, and tongue, minute, densely crowded, villiform. Opercular bones unarmed and scaly, except the interoperculum, which is naked and skinny. Dorsal fins united; ventrais seven-rayed. Branchiostegals four.

**Genus XX. Citrus**, Valenci. (_Leucis_, Lowe.) Body compressed, keeled anteriorly, clothed wholly with smooth scales. Head small, truncated, scaly. Preoperculum furrowed on the limb, with an entire margin without spines; operculum, suboperculum, and interoperculum without spines or serratures, but sub-ciliated. A single series of very small seaceous teeth. Dorsal, anal, and caudal fins scaly. Branchiostegals six.

**Genus XXI. Scorpaena**, Valenci. Unites the characters of Trachinidae and Platax, and, for the teeth covering all parts of the roof of the mouth, ought have entered the latter genus. Body compressed, oval. Muzzle short and rounded, forming part of the circumference of the oval profile. Broad band of villiform teeth on the jaws, vomer, and palatines; those on the pterygoid bones exceedingly minute. Most of the head scaly. Scales strongly ciliated. Ventrais, a spine, and five articulated rays. Two species.

**Genus XXII. Pempheris**, Cuv. Similar to Brana in outline, except that the occiput and shoulder are less convex, and the posterior parts taper more. The teeth are villiform. The short and high dorsal is over the posterior half of the pectorals, occupying but little of the back, while the long anal resembles that of *Brama*. Eye large. Air-bladder double as in *Myripristis*. Resembles *Eurias*, but differs in the magnitude of the scales on the fins. Its short dorsal and scaly anal, with the existence of vomerine and palatine teeth, separate the genus from the *Sparidae*. Eight species.

**GENUS XXIII. TOXOTES**, Cav. A short compressed body, with the dorsal placed on the posterior half of the back. Very strong spinous rays; the soft parts and the anal scaly, and opposite to each other. Scales large. Snout depressed, short; mandible advancing beyond the premaxillary. Very short, close, villiform teeth on the jaws, end of the vomer, and palatines; also on the pterygoids and tongue. Minute denticulations on the border of the preorbital and opercular. Stomach short and large; twelve pancreatic ceca; air-bladder large and thin-coated. One species.

**GENUS XXIV. HOPLOXANTHUS**, Rich. (March 1841.) (*Scorpaena*, Schleg., 1844.) Compressed body, like *Chromis*; with the soft dorsal and anal opposite, and scaly; spinous portion of the dorsal longer, but lower than the soft part; ventrals little behind the pectorals. Jaws and teeth of *Scorpaena*. Scales feebly ctenoid, imbedded deeply in the skin, few on the head, and confined to the temporal region. Branchiostegals seven. Three or four species.

**RIBBON-FISH.**

A natural family nearly allied to the *Scomberoids*, and having bones of a still looser texture than the *Mackerels*, in most little more solid than a fibrous net-work. Cuvier included *Lepidopus* and *Trichurus* in this family, but we have followed M. Valenciennes in placing these two genera at the end of the first tribe of *Scomberoids*, and along with them *Nemichthys*, whose greatest affinity seems to be with *Trichurus*. M. Valenciennes, however, considers the two genera in question to be a link between the families, and to be connected with the elongated *Scomberoids* by their strong compressed curved teeth; while they have an equal relationship to the *Teniods* by the presence of ventrals merely in a rudimentary condition, or their entire absence.

The first tribe, being the Ribbon-fish, which have small mouths, includes those to which this family name applies best, because species exist which are nine or ten feet long, yet are not six inches high, and scarcely an inch thick. The *Trachypterus* have several rays in the ventrals; the *Gymneteri* only one or two filamentous rays; and *Stylephorus*, still imperfectly known, appears to be truly apodal. Few fish of so much interest, from the singularity of their appearance, and the peculiarities of their structure, are so imperfectly known. This arises in a great measure from the delicacy of their texture. They are constructed for inhabiting the still waters of great depths, and are seldom seen except when thrown ashore in tempests. Their tender fins are easily mutilated, their thin soft flesh rapidly decays, their bones have too little firmness to keep the skeleton together when rudely handled, and they almost never come before a naturalist in a perfect condition. M. Valenciennes had twenty individuals under examination when he drew up his history of the family, and he has done much to remove the confusion which the imperfect and contradictory descriptions of authors, framed on mutilated specimens, had created. The *Trachypterus*, he says, are extremely tender, and their fins brittle, and their entire form can be seen in very young individuals only. The woodcut fig. 4 represents one species, *Trachypterus falcis*, which has 168 rays in its dorsal fin, and plumes of rays on the head and tail. This fish shines with the most brilliant silvery tints, and when moving freely in the water, its varying hues relieved by three large round black spots on the sides, must render it one of the prettiest of the many elegant fish that the seas produce. The anatomy of *Trachypterus leiopterus* is given in the *Histoire des Poissons*, and the stomach is there described as cecal, long, and narrow, with a very short ascending pyloric branch arising from its lower third part. The pancreatic ceca are almost innumerable, and open into the intestine by two parallel rows of holes. It had no air-bladder. The *Vaengmaer*, or *Deal-fish*, has also been recorded by Dr Fleming as a British species. It is the *Trachypterus bogmarius* of the *Histoire des Poissons*, the *Gymneterus* or *Gymnoaster arcticus* of previous authors, and is described in the *Natural History of Iceland*, written in 1658 by Jon Gundmundsen, a native of that island. Nilsson includes it among the Norwegian fish, but as one very rarely seen. The Supplement to Yarrell's *British Fishes* contains a figure and description of one taken in Iceland, translated from a memoir by Reinhardt, curator of the Museum at Copenhagen. The *Gymneterus Hackinsi* is another rare British Ribbon-fish. The *Stylephorus chordatus* of Shaw was taken in the Gulf of Mexico, and is known only by a single specimen in possession of the College of Surgeons of London, but which is not, unfortunately, in the best condition. The long filament from which it derives its name is considered by Blainville to be a prolonged ray of the caudal fin, and not a lengthened spine as in *Trichurus*. The *Cepola rubescens*, Red-band Fish or Red-snake Fish, belonging to the second tribe of Ribbon-fish, though not common on the English coast, is sometimes taken in numbers, as was the case about twelve years ago in Torbay.

**FAMILY XIX.—TENIIDÆ.**

**TENIIDÆ OU POISSONS EN RUBAN**, Cav. Compressed, elongated, ribbon-shaped fish. Skin naked and silvery. Long dorsal often joined to the caudal; the anal when it exists similarly connected; the articulated fin-rays for the most part simple; soft rays of the ventral never exceeding five, sometimes reduced to one or two, attached to the throat. This character brings them near the *Blennius*, while the small mouth and protracile snout of *Trachypterus* indicate some analogy with the *Zeidae*.

**ANALYTICAL TABLE OF THE TENIIDÆ (Dum.)**

| Dorsal conspicuous, and | Cepola | 4 | |------------------------|--------|---| | Long, without spines | Lophotes | 5 | | Short, and far back | | |

**Tribe I.—Mouth not wide; jaw protractile.**

**GENUS I. TRACHYPTERUS**, Cav. (*Reganurus* and *Gymnoaster*, anc.) Pectorals of moderate size or small; ventrals often greatly developed, attached under the axilla of the pectorals, and having several soft rays (four to seven). Body elongated and compressed like a ribbon or blade of a sword; skirted along the whole dorsal edge by the dorsal fin, the anterior part of which, separated by a notch, rises like a tall slender fan. Mouth extremely protractile. Caudal having an upper lobe similar to the first dorsal in form and height, and a few very short rays on the lower lobe; between these there is a small filament. Lateral line armed with scales, each carrying a hook. Jaws with visible teeth. Skeleton fibrous but extremely hard. Fins brittle and wearing down by age. Branchiostegals six or seven. Six species.

**GENUS II. GYMNETERUS**, Cav. Ventrales reduced to a single elongated ray, which is often dilated at the extremity. Branchiostegals four, five, or six. Eight species.

**GENUS III. STYLEPHORUS**, Shaw. *Trachypterus* with the point of the tail prolonged in form of a slender cord twice the length of the body. Dorsal commencing over the operculum, and extending to very near the posterior extremity of the fish, on which is the caudal, placed so as to resemble a second dorsal; the long cord which terminates the tail is the lower ray of this caudal. No visible scales. No visible trace of ventrals. One species.

**Tribe II.—Teniidæ, with a moderately large mouth.**

**GENUS IV. CEPOLA**, Linnaeus. Head much like that of *Amblyopus* and *Ophidion*, but with a large eye. Body greatly elongated and very much compressed, with a dorsal reaching from the head to the caudal, and an anal but little shorter. Caudal pointed; ventrals This family is entirely strange to the European seas. Gronovius described the first known genus under the name of Hepatus, which Linnaeus afterwards changed to Teuthyes, a name unfortunately used also to designate a genus of Cephalopods, and which on that account has been replaced in later times by Forskål's term of Siganus. The name of the family has, however, been preserved in the Histoire des Poissons, as derived from the Linnaean appellation. The group is a natural one, having the characters assigned to it in the table, and a family physiognomy easily recognisable. They are common enough fish in the Indian and Pacific oceans. One species is known as the "coral shoemaker" at the Seychelle Islands. They feed on marine algae, and must be pretty objects in the coral basins that they frequent, where the clearness of the water allows them to be distinctly seen. They are not the objects of any special fishery, and their history can be best studied in the detailed account of species contained in the Histoire des Poissons.

No. 16 represents Nasus longicornis.

Family XX.—Teuthydidæ, Bonap.

Teuthyes, Cuv. Oval forms, compressed. Small mouth, not protrusive. Uniserial teeth on both jaws. Palate and tongue toothless. A single dorsal. Branchiostegals four or five. Scales cycloid. Pectorals moderate in size. Ventrals under the axil of the pectorals. Many of the genera have the sides of the tail armed, or a recumbent spine in front of the dorsal. Phytophagous fishes.

Analytical Table of the Teuthydidæ (Dum.)

Sides of the tail armed with—

Several bucklers in one row..................Prionurus 3. Two moveable plates with trenchant edges........Nasus 2. A movable blade in a furrow..................Acanthurus 2. A fixed blade, trenchant on both edges........Axinurus 5. Sides of the tail unarmed........................Amphacanthus 1. Dorsal deeply notched and double..............Keris 7. Dorsal simple, spinous in front..................Priodon 6. One dorsal spine elongated.....................Amphacanthus 1. Several (five) dorsal spines, of equal height....Priodon 6.

Genus I. Amphacanthus, Bloch. (Basse, Commer.; Siganus, Forsk.; Cesuropanther, Houtt.) The peculiar character of this group is to have a spine in the ventrals on each side of the articulated rays which vary from three to five; in other respects they resemble the body oval. Mouth small and not little premaxillary. Teeth small, denticulated and uniserial. Five branchiostegals, the last one dilated and concealed in the throat. A recumbent spine in front of the dorsal; numerous spinous rays in the anal. The epicoecoid is cylindrical or prismatic, and is relaxed so as to be attached to the anterior intermusculars of the anal. The spines of the dorsal are thirteen, and only accidentally fourteen; the anal spines seven. Thirty species.

Genus II. Acanthurus, Forsk. A strong moveable trenchant spine on each side of the tail. Head elevated, compressed. Eye high up. Five branchiostegals. Teeth uniserial, incisorial, denticulated. A single dorsal. Skin thick, generally clothed with small scales. They want the additional spine in the ventrals which distinguishes Amphacanthus; and the epicoecoid is not developed as in that genus. Fifty species.

Genus III. Nasus, Cuvier. Tail armed with two ossuous bucklers carrying recumbent spines, not moveable. Teeth conical, pointed, without denticulations; a horn-like projection above the mouth. Five branchiostegals, more rarely five. Three articulated rays on the ventrals and a spine; spines of the dorsal five or six, and two in the anal; soft rays in both fins numerous. Intestinal canal extremely long; four pancreatic ceca; a pretty large air-bladder. Fourteen species.

Genus IV. Prionurus, Lacép. Teeth crenulated as in Acanthurus, in which the genus differs from Nasus. Tail armed by a series of horizontal, fixed, trenchant spines; a coanchet spine before the dorsal. Branchiostegals five. Five pancreatic ceca. Two species.

Genus V. Axinurus, Cuv. et Valenci. Distinguished from Nasus by a more elongated form similar to that of Teuthyes. A very small mouth, and consequently slender teeth. Armature of the tail consisting of a single blade cut squarely like the edge of a hatchet, and not springing from a buckler. It resembles Nasus in its general roughness, and in having three soft ventral rays. Branchiostegals five. Spinous rays of the dorsal four; of the anal two. One species.

Genus VI. Priodon, Cuv. Allied at once to Nasus, Acanthurus, and Amphacanthus, forming an intermediate link of union between them. Branchiostegals three. Spines of dorsal five, and of anal two. Teeth serrated as in Acanthurus. Ventrals having only three jointed rays as in Nasus. Forehead a little enlarged before the orbits, and the tail without armour as in Amphacanthus.

Genus VII. Keris, Cuv. The advanced position of the ventrals before the pectorals and immediately under the head distinguishes this genus from the rest of the family, though it has affinities with them. The teeth fine, smooth, and pressed one against the other as in Ammodytes. Tail without armature as in Priodon. Spines of the dorsal seven; of the anal three; ventrals of five soft rays and a spine. No scales, but the skin is granulated so as to resemble mosaic.

Flute-Mouths.

This family, established by Cuvier under the name of Fistulares or Bouches-en-flute, is not described in the Histoire des Poissons, the rich accumulations of species in the Paris Museum remaining still unpublished; and we are unable to add anything of moment to the account of the family contained in the Regne Animal, ii., p. 267. Specimens of several members of the family are imported in the insect boxes which the Chinese keep for sale to Europeans, and which contain many small fishes dried and pinned down like insects, often of curious forms, that reach our museums in no other way.

Fig. 12 represents one of the abbreviated forms of the family in the Australian Centriscus humerosus. Family XXI.—AULOSTOMIDÆ, MÜLL.

Bouchet-en-Flute, Cuv.; Aulostoma (Réhrenmouller), Müll.; Aulostomaride, Cant. Characterized by the prolongation of the nasal, vomer, preopercular, interopercular, pterygoids, and tympanics, into a long tube, with the mouth at the extremity, formed as usual of the premaxillaries, maxillaries, palatines, and mandible. The intestines have no great dilatations nor many folds, and the ribs are either short or wholly absent.

Analytical Table of the Aulostomidæ (Dum.)

| Dorsal single, and | Aulostoma 2 | |-------------------|-------------| | Proceeded by spines | ------------- | | Not preceded by spines | Fistularidei |

| Dorsals two. | |--------------| | Conspicuous, the first ray stiff, denticulated | Centriscus 4 | | Sheathed beneath a kind of shield | Amphisile 5 |

Genus I. Fistularia, Linn. Mouth of small extent, placed at the extremity of the tubular face, having a nearly horizontal gape. The elongated head constitutes a third or fourth part of the entire length of the fish, which is itself long and slender. Branchiostegals six or seven. Bony processes stretching from the head give support to the anterior part of the body. Stomach a straight fleshy tube; pancreatic caeca two. Dorsal single, opposite the anal, and composed mostly of simple rays. Small teeth on the premaxillaries and mandibles, but not sometimes as long as the body issues from between the lobes of the caudal. Rostral tube very long and depressed. An excessively small air-bladder. Invisible scales. Four species.

Genus II. Aulostoma, Linn. Dorsal preceded by some free spines. Jaws toothless. Body distinctly oval and less slender than that of Fistularia; compressed and higher behind than the dorsal and anal. Tail short and finer, terminated by an ordinary caudal without the filament; the facial tube is also shorter, thicker, and more compressed than in Fistularia. Air-bladder very large. One species.

Genus III. Polypterichthys, Bleek. Separated from Aulostoma by possessing mandibular, vomerine, and palatine teeth. Tenatae.

Genus IV. Centriscus, Linn. Body oval or oblong, compressed and mucilaginous. Belly. Two or three slender branchiostegals. A spinous dorsal pretty far back, with a strong first spine. Small ventrals behind the pectorals. Mouth very small, opening obliquely. No pancreatic caeca. Intestines folded three or four times; a considerable sized air-bladder. Large denticulated plates support the strong anterior spine of the first dorsal; the rest of the body is covered with small scales.

Genus V. Amphisile, Klein. Back enframed by large scale patches whose summit is crowned by the strong dorsal spine; in some, scaly pieces arm also the flanks and the spine, and the second dorsal and anal are crowded towards the base of the tail; in others, the cuirass covers only half the back, and the spine is farther forward.

Gobioids.

This family includes many very curious forms, differing greatly from one another in external aspect, and assembled together chiefly by the flexible nature of their spinous rays; but even that character is not positive, since in some the spines are pretty pungent. It has been made in some degree a receptacle for genera that could not be placed in other groups, though they exhibited no very marked affinity for the typical Gobioids. As first conceived by Cuvier, it included the Blennies also, but these have been since separated, and Müller has added the Discoboli of Cuvier, which cannot, he thinks, be kept apart from the Gobioids. The Gobioids have thoracic ventrals, and most of them have these ventrals united by their interior borders to form an oblique circular, infundibuliform disk, the front border of the disk being membranous and lower. This character does not, however, extend to all the genera. The Koloi of Aristotle were not the Gobies of the moderns, since he describes his fish as having numerous pancreatic caeca, whereas our Gobies are destitute of these organs. The Goby of Ausonius is a Gudgeon, and reasons are assigned in the Histoire des Poissons for the Koloi of Aristotle and the Kolos of Athenaeus being the Cottus gobio, and not a Gobioid at all; while the Phukis of Aristotle is considered to be the name given by him to the real Gobies. He classes these fish with those which frequent rocky places, and live upon marine algae and crustacea, which change colours with the season, and which are, according to his observations, the only fishes of the sea which make a nest of leaves, and deposit their eggs therein. In a preceding page, we have mentioned the Sticklebacks as having also this habit. M. Mertens relates, in fact, that the Gobius capito (erroneously considered by him as identical with G. niger) of the Mediterranean, makes a nest of algae and zosterae; that the male remains at it to impregnate the eggs of the females which come to lay there; and that he watches over the eggs and protects the young after they are hatched. The Black Goby, Double Spotted Goby, Spotted Goby, and Slender Goby, are enumerated by Mr Yarrell as British species. The Chinese waters nourish not only many Gobies similar to the European species in general aspect, but also some very peculiar forms. Among these is Trypauchen vagina, the Hung-loe of the Chinese, of which the generic character consists in a deep pit on each side of the nape, not however communicating with the branchial cavity; and Amblygobius, a genus of several species, and of a very curious aspect. The Chinese generic name is Shay-king or "Warp-snake?" king meaning the warp of a web of cloth, evidently referring to its long anguilliform body. The face is very strangely wrinkled, and the eyes exceedingly small.

The Periophthalmi and Boleophthalmi are lively fish of elongated forms, with the united ventrals of the Gobies, and large, gay dorsal fins spotted like the wings of a butterfly. They have narrow gill-openings, and spend much of their time out of water, hopping over the moist sands left by the retreating tide, and spending a kind of amphibious life, pursuing the Crustaceae which live on the sands, and, when menaced by a bird of prey, diving into the mud. Their eyes are protected from injury, when they resort to this means of escape, by moveable adipose lids. The Boleophthalmi are named from the power they possess of thrusting out their eyes when they wish to look around them; when the eyes are retracted, the membranous cellular lid swells over them. The thick double lips of these fish, and their hunting habits, are expressed by the Chinese name Peih kow-kow, "Broken-mouth dog."

Electris has not united ventrals, and has the aspect of a Scianoid, but with a smaller depressed head. Like most of the Gobioid family, organized for living on muddy or sandy bottoms, the mucigenous functions of the skin are called largely into action, and numerous mucoducts open on the surface. This gives them somewhat of the appearance of Eleginus, and of the Scianoid genera that come nearest to it; also of Borichthys, a Percoid form belonging to the Uranoscopidae, and in fact to the ground-fish cf **ICHTHYOLOGY**

**Classification—Acantopterous Fishes.**

Several families. Allied to *Electris* and *Philypnus*, by family aspect, is *Notothenia*, of which numerous species inhabit the higher latitudes of the southern seas—the Falklands, Cape Horn, South Shetland, &c. *Gadus Magellanicus* of Forster, of which there is a drawing in the British Museum, is a member of this genus.

In Wiegman's *Archivum* (ix., p. 295), Müller has assigned his reasons for uniting Cuvier's *Cyclopterus* to the Gobioidei. Two species of *Lepadogaster*, a *Cyclopterus*, and two of *Liparis*, are described by Mr Yarrell as British fish. The *Cyclopterus lumpus*, or "Cock-pielle" of the fishermen of the Firth of Forth, is mentioned with respect for its good qualities by Sir Walter Scott in his novel of the *Antiquary*, and it appears frequently in the Edinburgh fish-market. It is not very rare on the English shores, but its qualities are less appreciated there. The appearance of the dorsal fin, resembling the crest of a cock, is the evident origin of the first part of its Scottish name, and its mode of swimming or paddling of the second.

*Callyognathus* is a genus of many species, some of them very gaily and handsomely coloured, with large dorsal fins, and bearing a considerable resemblance to the *Sclerogonidae*, from the armature of the preoperculum. They are considered by M. Valenciennes to possess characters sufficient to erect them into a separate family; but he has abstained from doing so until he has studied the peculiarities of their structure by the examination of a greater number of species than he had collected at the date of the publication of the 12th volume of the *Histoire des Poissons* in 1837. One species is common enough on our sandy shores, and the female, which has smaller fins and duller tints of colour, is often described as a distinct species.

*Harpagifer* differs from *Callyognathus* in having wider gill-openings. *Comephorus* is an apodous fish of Lake Baikal, of very rare occurrence, since it inhabits the greatest depths of the lake. It is destitute of scales, has a small stomach, no pancreatic cæcum, and no air-bladder. Its bones are soft and fibrous. It is obtained only when violent north winds cast it ashore in the spring time. So oily is its flesh that it cannot be eaten, and even the carrion crows refuse to touch it.

*Channichthys* is a southern fish, being an inhabitant of the groves of kelp which skirt the shores of Kerguelen's Land. It is a voracious fish that takes the hook readily, and has somewhat of the aspect of a Gurnard, but its cheek is not malled. In the structure of its bones it comes nearer to the *Lophididae*.

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**TABLE OF THE GOBIIDEI.**

| Ventrales united, infundibuliform. | Body sword-shaped. | |-----------------------------------|-------------------| | A cavity on each side of the nape | Trypauchen | | No branchial cavities | Amblyopus | | Body more or less cylindrical. | | | Dorsal solitary, and | Apocryptes | | Notched in the middle | Gobioides | | Not notched | | | Dorsals two | | | Eyes near one another | | | Teeth equal | Boleophthalmus | | Teeth unequal | Periophthalmus | | Eyes farther apart | Gobius | | Ventral united in a shallow basin | Sicydium | | Ventrales recurved | | | A ventral disk, behind the pectorals | Platytetanus | | The ordinary scale thoracic integument | | | Pomering teeth | Philypnus | | No pomering teeth | | | Lateral line continuous | Eleotris | | Lateral line broken | Notothenia |

**Genus I. Gobius**, Linnaeus. Ventrales united a little posterior to the pectorals, forming a hollow disk; two dorsals, spines of the first one flexible, the second one pretty long. Body elongated. Head of moderate size, rounded. Cheeks convex. Eyes approximated. No air-bladder. Villiform teeth, milk teeth, often with a stronger anterior row, appearing to canines. Scaly fishes with or without flaps on the head. One hundred species.

**Genus II. Gobionellus**, Lacépède. Differs from *Gobius* in the spinous rays and articulated ones on the back being united into one long low fin, which reaches nearly to the caudal. One species.

**Genus III. Apocryptes**, Valenciennes. Teeth on the jaws uniserial, the mandibular ones almost horizontal, with two canines standing more interiorly and close together; in other respects *Gobius* with two dorsals. Elongated bodies. A long pointed caudal. Generally small scales. Five species.

**Genus IV. Trypauchen**, Valenciennes. A deep hole on each side of the nape not communicating with the branchium; in general form like *Amblyopus*, having a single long dorsal and an anal united to a caudal with longer rays. One species.

**Genus V. Amblyopus**, Valenciennes. Elongated fishes, with the ventrales of the body. Mouth vertical, armed with strong curved teeth, not covered by the lips. Eyes extremely small. The long low dorsals united to the caudal. Scales small. Six species.

**Genus VI. Sicydium**, Valenciennes. *Gobius*, with the ventrales forming a shallow round basin adhering almost equally throughout its circumference. Teeth on the jaws flexible in a close row, with some strong interior ones on the mandible. Four species.

**Genus VII. Periophthalmus**, Schneider. Head wholly scaly. Eyes close together, having an inferior eye-lid which can cover them. Pectorals scaly for more than half their length, giving them the appearance of having an arm like *Lophius*. Ventrales united as in *Gobius*. Teeth uniserial, more or less vertical. Narrow gill-openings. Profile descending rapidly, forming with the nape an angle, on which the pretty large prominent eyes are placed. Scaly fishes, with the four ventrales distinct; in some the ventrales are deeply divided. Eight species.

**Genus VIII. Boleophthalmus**, Valenciennes. *Periophthalmus*, with teeth analogous to those of *Apocryptes*; those of the upper jaw being straight and pretty strong, especially towards the symphysis, while the mandibular ones are very fine, and disposed horizontally, with two more interior taller pointed ones. Head more oblong, and the profile less vertical than in *Periophthalmus*. Scales small, in some almost imperceptible. Five rays in the first dorsal. Pec- TABLE OF THE DISCOBOLI.

Form elongated, depressed, or subcylindrical.

Vertical fins united.........................Liparis 20. Caudal separated............................Gobiesox 15. Gills four..................................Gobio 18. Gills three.................................Cottus 16, Sicyaena 17, Sicyogaster 18. Ventral disks, two..........................Lepadogaster 13. Form jumpish, thinner on the back; disk single Cyclopterus 9.

GENUS XIII. LEPADOGASTER, Gouan. Ample pectorals, which descend to the throat where their rays are stronger, and where the two fins are united by a transverse membrane extending forwards, and prolonged from the union of the two ventrals. Body smooth, scaleless. Head large and depressed. Mouth projecting, protrusive. Gill-openings not wide. Branchiostegals four or five. One dorsal only, consisting of soft rays opposite to an anal fin of like form. Intestines short, straight; no pancreatic ceca; no air-bladder.

In the typical species (Porto-Escolle, "Regna Animalia") there is a circular concave disk under the public bones formed by the otherwise little developed ventrals; and a second disk before it less complete, formed under the coracoid by the pectorals. Eight or ten species.

GENUS XIV. TRACHEOCHIRIMUS, Barn. In this genus, as in Lepadogaster, there are two ventral disks, by which they are distinguished from the allied genera in which there is only one lateral, single-notched disk. The gill-openings join, but in Lepadogaster they are separated.

GENUS XV. GOBIOSOX, Lacap. Have not the double disks of Lepadogaster; but the pectorals and ventrals form a single large disk split on each side, and prolonged there by membranes; dorsal and anal short, and separated from the caudal. Gill-openings larger. G. dentex.

GENUS XVI. COTTUS, Mull. and Trosch. (Chlorocottus, Barn.) Teeth of Gobiosox; a row of conical teeth on the jaws; behind the fore bigger ones a mass of smaller ones. They differ from Gobiosox by having only three gills; and by the branchiostegal membrane of both sides being attached to the isthmus, without covering it by an overhanging cuticular mantle or free border of skin. One species. C. maculatus.

GENUS XVII. SICYAENA, Mull. and Trosch. (Remicodon, Barn.) Resembles Cottus in having only three gills, and in the insertion of the branchiostegal membrane, but it has only a solitary row of teeth in the jaws, the middle and bigger ones being incisorial, the lateral ones conical. One species. S. anguineus.

GENUS XVIII. SICYOGASTER, Barn. Distinguished from Sicyaena by the cutting mandibular teeth; the other teeth are conical. S. macromerus.

GENUS XIX. CYCLOPTERUS, Linn. Ventrales encircling the public bones united into one by membrane and forming an oval concave disk, which is used as a sucker by the fish to attach itself to a rock. Mouth large. Teeth on the jaws and pharyngeals small, pointed. Opercula small. Gill-openings closed below. Branchiostegals six. Pectorals very large, and uniting nearly under the throat to embrace the ventral disk. Skeleton but slightly ossaceous. Skin viscid, scaleless, but containing small hard grains. A pretty large stomach, with a pancreatic ceca; a long intestine; a moderate sized air-bladder. In the typical species the first dorsal is more or less visible, though very low, and is composed of simple rays; the second dorsal, having only strong rays, is opposite to the anal. Body short and thick as well as high.

GENUS XX. LIPARIS, Art. Differs from Cyclopterus in having an elongated body, compressed posteriorly, and a single pretty long dorsal with a corresponding anal. Skin smooth.

The eight preceding genera form the Discobolii of the Regna Animal. The following genera are said, in the Histoire des Poissons, to be manifestly related to the Gobiosci, but to have characters which prevent their being types of peculiar families.

GENUS XXI. CALLIONYXUS, Linn. Gill-openings reduced to a small hole on each side of the snout. Ventrales widely separated, larger than the pectorals, and attached to the ventral surface of the throat. Head unarmed and depressed. Mouth very protrusive. A process more or less elongated issuing from the inferior angle of the preoperculum, and terminated by distended lips. Villiform teeth on the jaws, none on the palate. First dorsal elevated. Its rays flexible and setaceous; second dorsal and anal long. Skin generally smooth. Stomach not cecal; no air-bladder. A genital papilla. Twenty-five species.

GENUS XXII. HARAPIGER, Rich. A Gobioidei, with the ventrales of Etheostoma, differing from Callionymus in having a pretty large gill-opening, which does not however descend to beneath the throat. Operculum and preoperculum bearing strong spines, none on the preoperculum or interoperculum. Two dorsals, the first sustained by four flexible rays. Teeth on the jaws slender, minute; none on the palate or tongue. Branchiostegals six. Stomach cecal; pancreatic ceca three; no air-bladder. Lateral line crossing the snout to join its fellow, ending under the middle of the second dorsal.

GENUS XXIII. TRICHOSONOTES, Bloch, Schneider. Agrees with Callionymus in the form of the ventrales, and in the simple intestinal canal, without pancreatic ceca. Body elongated, almost cylindrical, terminated by a large pointed caudal. Eyes almost touching on the dorsal aspect of the slightly depressed head. Villiform teeth on the jaws, palatines, and front of the vomer. Gill-openings very large, coming forward to beneath the eyes. Branchiostegals seven. Dorsal single, extending to near the caudal, its front rays simple, some of them elevated; anal also long, with simple rays in front. Scales. Lateral line straight, continuous. Stomach a long narrow sac, with the pylorus near its bottom; no pancreatic ceca; no air-bladder. One species.

GENUS XXIV. PLATYPTERUS, Kuhl and Van Hasselt. Two dorsals separated to some distance. A triangular horizontal head. Mouth under the end of the snout. Narrow bands of villiform teeth on the jaws, none on the palate. Large ventrales attached to the under surface of a flat breast, further back than the pectorals. Branchiostegals also. Genital papilla. No air-bladder. One species.

GENUS XXV. COMBERUS, Linn. Elongated, scaleless, tapering fish, with a short depressed head, and large terminal horizontal mouth. Very wide gill-openings. Seven branchiostegals. Very long pectorals, and no ventrales. Teeth extremely short, in bands on the jaws, cherron of the vomer, and palatines. Mandible slightly longer than the premaxillaries. Branchiostegals six. Eight flexible rays on the low first dorsal; second dorsal higher, long, like the anal, and terminating with it not far from the forked caudal, leaving a very slender naked part of the tail between the three ver- tical fins. Stomach small, pointed, cecal; no pancreatic ceca; no air-bladder. One species.

GENUS XXVI. CHLOROCOTTUS, Rich. Head large, depressed (but with flat vertical cheeks), wider than the elongated body, which tapers gradually in all directions to the caudal. Snout produced, flat, and wide. A large mouth, bordered above wholly by the premaxillary, the maxillary, which is articulated to the nasal, lying behind; the angles of the mouth are laterally protrusive, giving a great extent to the gape. Teeth small, curved in crown, bands on the jaws; few on the pharyngeals; vomer and palatines smooth; preorbital rough, radiated, of moderate size, the other suborbital and cheek scales naked. Ventrales situated before the pectorals, composed of a spine and five soft rays, the first three of which are enveloped in skin, and are very thick, the other two branched as usual. Eye large, lateral. Gill-opening ample, extending forward between the limbs of the mandible. Branchiostegals six. No scales. Lateral line running straight to near the caudal, where Mr Yarrell describes four species of the genus *Blennius* as having been detected on the British shores. The English seas also produce a species of *Pholis*. *Salarious* presents a singularity in its dentition, which distinguishes it from other fishes; its jaw teeth are implanted in the lips, and are very fine and slender, and so connected with muscular fibres that each can be raised or lowered independently of the others, or they can be moved in a mass by the motion which the fish imparts to its lips, as in some Sharks.

*Clinus* is the modern Greek name for the Gobies, and has been applied by Cuvier to designate a Blennioid group, which is distinguished from most of the other Blennies by the large number of its dorsal spines, and other characters mentioned in the table. It is a viviparous genus, and the male possesses a pointed tubercle, with an aperture at its tip, and a bulbous dilatation within the abdomen behind the rectum, into which a very slender deferent canal from the milt is seen to enter together with the urethra from the urinary bladder. This structure has a similarity to a penis, but it is remarked in the *Histoire des Poissons*, that it ought rather to be considered as a modified cloaca than as an organ homologous with that of the viviparous Vertebrata.

The *Tripterygions* are found both in the Mediterranean and in New Zealand, and have the same habit of hopping over the wet sands which is attributed in a preceding page to some of the Gobioids.

*Bregmaceros* is a very interesting fish, whose affinities seem to be with this family. It was first described by Dr Thompson in the *Annals of Natural History* under that generic name, from a drawing made in the China seas by Dr Cantor, and again, under a new generic name, by Sir John Richardson, from two examples of a different species brought home by Sir Edward Belcher from the same seas. In its ventrals it differs from all other known fish, but as a description will convey but an imperfect idea of their peculiar structure, the reader is referred to the ichthyology of the *Voyage of the Sulphur*, where he will find a magnified representation of these fins. *Illocoetes* and *Phiocetes* are two very nearly allied genera, described by Mr Jenyns in his account of the ichthyology of the *Voyage of the Beagle*. They were discovered at Cape Horn, and specimens have been procured at the same locality by Sir James Ross. *Gunnellus*, owing to its compressed body, and the parallelism of its dorsal and ventral profiles, resembles a Ribbon-fish, and its name has a similar origin to that of Deal-fish, being from gun-neale, contracted into gunnel, the narrow board that forms the upper streak of a boat. In some species there is merely a minute, blunt spinous point to represent both ventrals. One species occurs on the British coasts abundantly, and there are others in all parts of the Arctic seas. There is much resemblance in form between some *Gunnelli* and the *Ophidion*, and perhaps a relationship.

The viviparous Blenny (*Zoarcus viviparus*) is a well-known species, and has been long celebrated for a peculiarity which is chiefly observable among cartilaginous fishes, that, namely, of producing its young alive. These are so matured at the time of their birth, that on their first exclusion they swim about with the utmost agility. No fewer than 200 or 300 young are sometimes produced by an individual, and the abdomen of the mother is so distended before parturition, that it is impossible to touch it without causing them to be extruded. Full-grown individuals seldom exceed 12 inches in length; the body is slender and smooth; the colour yellowish olive, pale beneath, and marked on the upper parts with dusky spots. It is a littoral fish, and of frequent occurrence under stones. When boiled, the back-bone acquires a green colour. America produces a much larger species, which sometimes exceeds the length of 3 feet. It has been described under the name of *Blennius labrus*. Sir Edward Belcher obtained some good specimens in Northumberland Sound to the north of Wellington Strait.

Notwithstanding the size of Anarhichas, its thickness, the total absence of ventrals, and the extraordinary nature of its dentition, it is impossible, says M. Valenciennes, to overlook the affinity that exists between the genus and Blennius. The proportions of the several parts, the forms of the head, the disposition of the fins, the delicacy of the scales, imbedded in the thickness of a slippery mucoid skin, are the same in both genera. The internal anatomy is also alike: short intestine, no pancreatic caeca, no air-bladder, and a similarity in the skeletons, ally them closely to each other, especially if we take for comparison the large American Zoarcus. The most common species (Anarhichas lupus) is of frequent occurrence in most of the northern seas, and is well known along the coasts of Britain by the names of Sea-wolf and Sea-cat. Its ordinary length is from 3 to 4 feet, but examples sometimes occur of nearly double that size. The colour is obscure livid brown, with several transverse stripes or bands of a darker hue. The dorsal fin, as already mentioned, extends along the whole length of the back, and is composed of seventy-three rays. The fore teeth project considerably, and diverge a little from each other, forming a powerful kind of armature, moved by jaws of such strength that the animal has been known to imprint the marks of its teeth on a bar of iron. The uninviting aspect of this fish has probably not been without influence in producing a prejudice against it as an article of food. Its flesh, however, is far from being unsavoury, and bears considerable resemblance to that of the Eel. It is in great request among the Icelanders, who eat it dry and salted; while the other parts of the fish are likewise converted to useful purposes, the skin forming shagreen, and the gall being used as soap.

The vascular tubes of the teeth are very large in the Wolf-fish, and were early recognised as such by anatomists.

Opistognathus is a genus of which one species has been found in the Indian Ocean, and another in the Gulf of Mexico.

**Family XXIII.—Blenniidae, Müll.**

*Parr Goldioides, Cuv.* With much of the structure of Goldi, the Blenniidae have a character common to most of the genera in the jugular ventrals composed of two flexible rays, sometimes with a spine, but more generally without. Stomach thin, without a caecal dilatation; no air-bladder. Body elongated, compressed. One dorsal, composed almost entirely of simple but generally flexible rays. Skin very muciparous, scaly or naked. A genital papilla.

**Analytical Table of the Blenniidae (Dum.)**

| Body scaleless. | Head crested. | |-----------------|---------------| | Gill-openings large. | Teeth numerous, firm. | | Teeth labial, moveable. | Gill-openings narrow. | | Teeth regular. | Teeth irregular. | | Head destitute of eyes or tentacula. | Dorsal spinous. | | Dorsal soft, without spinous. | Body scale. | | Dorsal solitary and united to the other two vertical fins. | Continuous without a depression. | | Suddenly depressed near the end of the tail. | Isolated. | | Ventrales distinct. | Ventrales four of them mandibular. | | No barbels; maxilla prolonged. | No barbels; maxilla not prolonged. | | Ventrales none or rudimentary. | Replaced by a spine. | | Genus I. Blennius, Linn. | Genus II. Pholis, Flem. |

**Genus I. Blennius, Linn.**

Body elongated. Skin soft, muciparous, scaleless. Gill-openings large. Branchiostegals six. Ventrales attached to the throat consisting of two rays externally, but the last of the two often divided under the skin; the flexible rays, termed spinous, are little in their structure from the others, being many of them obsolete or joined, though simple and tapering; dorsal single, extending along the whole back. Filaments over the eyes. Nostrils or nares of various forms. Mouth small; cleft at the base into a semicircle. Teeth uniserial, strong, simple, crowded, the row often terminated on each side by a canine. Intestinal canal simple; no pancreatic caeca; no air-bladder. Aperture of the ovary between the anus and urinary canal; and without a papilla in the female. A tuft of papillae round the opening of the seminal duct in the male. Thirty-five species.

**Genus II. Pholis, Flem.**

Blennius destitute of supraorbital cirri, or fleshy crests. Four species.

**Genus III. Petroscirtes, Hopp.**

(Blennichis, Valenc.; Osteobranchus, Ehren.) Blennioids, with the gill-openings closed beneath, and consisting of three rays, each attached above the base of the pectoral; their dentition is a modification of that of Blennius. The inferior incisorial teeth, attached to the front only of the mandible in a transverse row, are terminated on each side by a canine, sometimes enormously large, strongly curved, and fitting into holes in the roof of the mouth when the jaws are shut. Dorsal undivided; cirri generally present. Fifteen species.

**Genus IV. Blennophis, Valenc.**

Near Petroscirtes. Body compressed, scaleless. Head oblique. Mouth small. Four recurved, hooked teeth in each jaw near the symphysis. Dorsal single, noncirri; anal like the dorsal, but shorter; caudal distinct; pectoral rays curved; branchiostegal ventrals two-rayed.

**Genus V. Chasmodes, Valenc.**

Gill-openings above the pectorals, as in Petroscirtes. Anal with deep cliff, armed with teeth in front only, uniserial, firm, and regular; an even dorsal, extending from the top of the head to be united to the base of the caudal; anal similar, but only half as long, and not connected with the caudal. Body oval, oblong, destitute of scales. Branchiostegals six. No cirri on the head. Three species.

**Genus VI. Salarias, Cuv.**

Blennioids, with uniserial, almost innumerable, extremely slender, contiguous teeth, movable together by the impulse of the lips, like the keys of a piano or harpsichord. Head strongly compressed above, wide transversely below. Intestines rolled up itself in a spiral, and longer than that of the Blennius; no air-bladder. Thirty-five species.

**Genus VII. Pseudoblennius, Schlegel, vel Pseudotriques.**

Distinguished from the true Blennii by their general aspect and their card-like teeth.

**Genus VIII. Clinus, Cuv.**

Blennioids, with elongated, compressed, scaly bodies. Exterior teeth conical, pointed, with a villiform band behind; teeth on the vomer, and occasionally on the palatines also. Spinous rays of the dorsal numerous. Snout less blunt than in Blennius. Stomach larger, and intestine shorter. First rays of the dorsal sometimes separated from the others by a notch, sometimes detached to the head, where they form an elevated plastron; in other, the dorsal is continuous and even. Two spinous in the anal. Branchiostegals six. Twenty-five species, some of which have Labroid lips.

**Genus IX. Anthoclinus, Jenyns.**

Distinguished from Clinus by the larger number of spines in the anal—upwards of twenty; a longitudinal band of small teeth on the tongue; the position of the ventrals under the pectorals; and by the existence of three lateral lines. Branchiostegals six. Three species.

**Genus X. Myoxoedus, Cuv.**

Scaly fishes intermediate between Clinus and Gamellus. Head elongated. Snout pointed, projecting beyond the mouth. Teeth uniserial, as in Blennius, but without the canines; the larger teeth nearer the symphyses. Resemble Clinus in the great number of spinous rays in the dorsal; and differ from Gamellus in having some soft rays in that fin. Three species.

**Genus XI. Ctenogobius, Valenc.**

Blennioids, with the first three dorsal rays standing on the occiput, connected by a membrane and forming a separate fin from the long dorsal, which begins over the gill-opening and reaches to near the caudal, the eight posterior rays being articulated; anal shorter than the dorsal, and having only two spinous rays. Two species.

**Genus XII. Cirrhilabrus, Cuv.**

Myoxoedus, with still more numerous spines in the dorsal, a few more soft rays; tentacles numerous on the snout, mandible, maxillary, and over the orbit. Teeth villiform as in Clinus. One species.

**Genus XIII. Tripterygion, Risso.**

Distinguished from Clinus by the dorsal being divided into three portions. Conical teeth in an arc above the jaws, and villiform teeth behind; a small transverse band of short ones on the front of the vomer. Branchiostegals generally six; in one species only five. No anal spines. Six species.

**Genus XIV. Bremaeckers, Thomp. (Ann. N. H.)**

Cirrhitichthys, Rich. (Voy. of Sulphur). Body fusiform. Head short, obtuse. Mouth The Lophioids were, from the softness of their bones, placed among the branchiostegous fishes by Artedi; but Cuvier recognising the fibrous structure of their skeletons, brought them back to the Acanthopterygii, and since then Müller has shown that the Ostracods with which Artedi had associated them are themselves osseous fishes. In fact, the whole organization of the Lophioids is that of an Acanthopterous fish; their two dorsals, the composition of the auditory organs, the freedom of the semicircular canals within the cranium; the construction of the digestive viscera; that of the organs of generation in male and female, the connections of the premaxillaries and maxillaries, and of the teeth which they support, as well as the mandibular, palatine, and vomerine teeth, are all characters of true Acanthopterii. The skeleton itself, though not hard, is fibrous; and this is the case in the common Lophius with respect to all the cranial bones without exception, those also of the jaws, gill-covers, scapular chain, the spinal column, the fins, os hyoidei, and gills, all of which have the fibrous structure.

Distinctive characters of the family are to be found in the almost general absence of scales, which are replaced in Malthrea by bony tubercles, and in many species of Cheironectes by small grains armed with spines; in the elongation of the ulna and radius into a kind of arm, whose fingers are represented by the rays of the pectoral; in the restriction of the apertures of the gills, and the absence of the suborbital bones, on which M. Valenciennes places much value as a family characteristic. Cuvier, in his memoir on the Cheironectes, traces their affinity to the Blennioids and Gobioids as follows:—The advanced position of the first dorsal exists in Cristiceps; Callionymus has only a small gill-opening; Gobius macrocephalus of Pallas has the head depressed and wide; the Periophthalmodon and Boleophthalmus have the pectorals supported on arms, and these fish walk and run over the mud in quest of their prey, like the Cheironectes; all these facts prove that the Lophioids are nearly allied to the Gobioids; most of them have, moreover, like these last, a simple intestinal canal, without pancreatic... In quoting these remarks from Cuvier, M. Valenciennes adds that *Lophius* nevertheless has two pancreatic caeca near the pylorus, and shows some relationship to the Percoids, from which, however, he gathers that in natural families there are analogous repetitions or representations of genera in the several groups. Many wonderful things have been said of *Lophius*, or the Fishing-Frog. It has arts and schemes strange and various; it fishes with a line; it fishes with a bait; and not content with gathering a crowd of fish around it by the temptation of its baited filaments, it engulfs them in its vast branchial bags, which sacs, sustained by branchiostegals of proportional size, have no opercular bones, so that, in short, the *Lophius* is an isolated genus, differing from all others in organs connected with its respiration. But in truth the *Lophius* possesses exactly the same bones which enter into the composition of these parts in other fishes; the proportion alone differs, and the enormously large head has given rise to much of the marvellous in these descriptions. The organ of smell is that in which the *Lophius* differs most from other fishes, whether they are osseous or cartilaginous. It has two orifices to its nostril, as is usual, but they are not easily found, unless sought for at the extremity of the nostril tube in an uninjured specimen. This organ is supported on a membranous stalk, and when one opens its summit, it spreads out like the cup of a flower. The bottom of this cup is divided into projecting leaflets, on which the olfactory nerve is distributed, after traversing the axis of the foot-stalk. The fish erects these stilted nostrils, and turns them towards any object whose odour it wishes to ascertain, much as a Slug elongates its horns. In fishes in general the plaited pituitary membrane is fixed immovably at the bottom of a cavity excavated in the bone. The opercular bone in this fish is long and strong, is suspended vertically from the convex epitypanic condyle (as in *Diodon* and *Anguilla*), and has a long slender fin-ray proceeding from the back part of the joint. The suboperculum is produced backwards, and is divided into slender branches towards its border-like fin-rays, as in the Plagiostomes. The anterior rays of the dorsal situated on the head are articulated at their bases by rings, as represented by Mr. Yarrell. The spine is composed of thirty vertebrae, and the myelon terminates in a point at the twelfth, the rest of the neural canal being occupied by a long *canula equina*, or bundle of nerves. Except in the Lophobranchii, there is scarcely another instance among fishes of a similar structure, the myelon being generally co-extensive with the neural canal.

The *Lophius piscatorius* is common on the S. coast of England, and many are taken annually in Portsmouth Harbour. A second species is supposed to exist in the European seas, and a very similar one abounds in the China seas. Specimens of the young are generally pinned in along with other small fishes in the insect-boxes exported from Canton. The *Cheironectes* are small fishes, of frog-like aspect, and many of them have the faculty of distending their large membranous stomach with air, and so swelling out the body as the Tetraodon and Diodons do. The quadrupedal character which these fishes possess from the position of their pectoral and ventral fins is expressed by fig. 1, p. 206. The small hole in the axilla of the pectoral is the only gill-opening, and this structure, by retaining the moisture about their gills, enables these fish to remain long out of water, and to travel over sea-weed and sand in search of prey. Commerson considered them to be a kind of Amphibia. Many are curiously coloured, and have strange cutaneous appendages to the fins and other parts of the body.

*Malthoia* is a genus of fish of depressed forms, very wide in the pectoral region, and they are remarkable as being the only fishes of this family which possess a suborbital bone. *Halieutes* is still more depressed in the body than *Malthoia*, and dried specimens are very common in the Chinese insect-boxes. The species named *H. stellata*, is of an aurora-red colour above, and bright lake-red beneath. Its back is curiously murecated.

*Batrachus* is a genus of small fishes, of a disagreeable aspect, but which departs less from the ordinary piscine types in outward form than the preceding Lophiidae. It has much the aspect of some *Cotti*, to which the armature of its head bears also a resemblance. It differs, however, widely from the *Sclerogonidae*, in the cheek not only being not crenulated by the suborbital, but in that bone being altogether absent. The suboperculum is as large as the operculum, and is likewise armed with strong spines. The species are divided according to the naked or scaly condition of their skin, and by the presence or absence of barbels round the jaws.

**Family XXIV.—LOPHIDÆ**, Cuv.

*Pterorales pedicellata*, Cuv. Armflower of the Germans. Skeleton fibrous, rarely much indurated. Scales almost always wanting, replaced in *Malheira* by osseous tubercles, and in *Pterorales* by small grains which support spines. Forearms, that is the ulna and radius supporting the pectoral fin, prolonged, making a kind of arm. Gill-openings restricted to a round hole or vertical slit behind the pectoral, and not extending under the border of the suboperculum and operculum. No suborbital bones.

**Genus I. Lophius.** Head, in comparison with the rest of the body, excessively large, broad, depressed, spiniferous. Infundibular-form pedicellated nostrils. Very wide mouth. Conical slender teeth on the jaw palatines, and most frequently on the chevron of the vomer, on the superior and inferior pharyngeals, but not on the tongue. Branchiostegals six; branchiostegal membranes very extensive; branchial arches three. No supplementary gill adhering to the operculum. The operculum, suboperculum, and preoperculum concealed by the muscles, but the prooperculum more visible. There is no suborbital. Teeth moveable. Dorsals two, some of the rays of the first one far forwards on the head, detached from the others, produced into tall filaments which carry a cutaneous tag at their extremity; these rays are articulated by a ring to their internumeral bones, a mode of articulation which exists also in the *Chordotomidae*, *Siluridae*, and some *Cyprinidae*. Nostrils campanulate and pedunculate, stomach very large and very muscular; intestine short; two pancreatic caeca. Five species.

**Genus II. Chironectes**, Cuv. Head and body vertically compressed; nostrils placed on the head, sometimes united by membrane, but not followed by a spinous fin separated from the soft dorsal as in *Lophius*. Head neither very large nor the gape so enormous as in that genus. Most have the habit of inflating the body by filling a large membranous stomach with air like the *Tetraodon* or *Diodon*. The relative position of their ventrals and pectorals gives them the appearance of possessing four feet (see fig. 1, p. 206), but it is the ventrals that here represent the anterior limbs. Gill-opening a small hole concealed in the axilla of the pectoral. Mouth cleft more or less vertically. Fine slender and pointed teeth crowded in card-like plates on the premaxillaries, mandible, vomer, palatines, and pharyngals. Eyes small and far forward. Opercular bones wholly concealed by the integuments. Branchiostegals six. Branchial arches four. Body not tapering posteriorly in the same way with that of *Lophius*. Dorsal occupying much of the back; pectoral The Sclerodermats, or Balistini, are distinguished by the conical snout, a small terminal mouth, and distinct but not numerous teeth. In Balistes the first dorsal spine is articulated by ring and bolt to the broad interneural osseous plate. When the spine is raised, a depression at the back part of its base receives a corresponding projection from the contiguous base of the second ray, which fixes it like the hammer of the gun-lock at full cock, and it cannot be let down until the small spine has been depressed, as by pulling at the trigger; it is then received into a groove on the supporting plate, and offers no impediment to the progress of the fish through the water. (Owen.) This trigger-like fixing of the spine takes place also in the dead fish; and when a Balistes is removed from a bottle for examination, it is generally necessary to release the spine by pressing on the small trigger-ray. The spine of the Balistes is roughened with ganoid or enamel grains like a file, and the teeth of this fish consist of true dentine, with a thick layer of denser tissue that differs little from enamel.

In the Gymnoids, or Diodontidae, the maxillaries coalesce wholly or in part with the premaxillaries, and the teeth are incorporated with the bone of the jaws, so that the whole looks like one or two great teeth; but the teeth, individually small, are developed from pulps, are arranged in lamellae, and approach the cutting edge of the compound tooth or jaw as their predecessors are worn away, much as in Scorpa. The dental plates consist of hard or unvascular dentine. This kind of dentition is adapted to cut and bruise the food on which these fishes live—fuci and crustacea. None of them are used as food for man, and they are generally considered to be poisonous. An instance occurred a few years ago at the Cape of Good Hope of two sailors being poisoned by eating a Tetraodon, and dying from the effects thereof. A detailed account of the symptoms was drawn up by a surgeon in the Dutch navy, who attended them till they died, which was in less than half an hour after eating the deleterious fish. The Tetraodon and Diodons have the power of inflating their bodies by filling their stomachs with air. This viscus is very large, occupying the whole length of the abdominal cavity, and has very thin coats. When thus blown up into a globular form, the fins cease to play, and the fish turns over, and floats belly upwards, driving before the wind and waves, without being able to direct its course, until it has resumed its former shape, by expelling the wind. The inflation of the Diodons, however, causes the strong spines with which the skin is studded, and which resemble those of a hedgehog, to radiate on every Order VI.—PLECTOGNATHI, Cuv.

Endo-skeleton partially ossified; exo-skeleton as ganoid scales or spines. Maxillaries and premaxillaries fixed together. Swim-bladder without an air-duct. No pancreatic ceca; merely vestiges of ribs; and no distinctly developed ventrals.

Family I.—BALISTIDAE.

Sclerodermi, Cuv.; Balistini, Müll. Smooth conical. Teeth incisorial, more or less conical, and few in number. Skin either with shield-like scales or with small rough ones. Swim-bladder ovate, strong.

Sub-Family I.—BALISTINI, Kaup.

Whole body mailed in a cuirass divided into rhomboidal disks by cross lines, and commonly displaying varying tints of color that are generally lost in the preparation of the specimen. First ray of the anterior dorsal very stout and bony, followed by one or two small ones, all of them falling into a dorsal furrow; pectoral bones more or less projecting, and carrying the spinules of linear veniriae.

Genus I. PYRODON, Rüpp. (Xenodon, Rüpp.) Profile slightly convex, with the chin projecting. Four blunt front teeth, whereof the middle pair are the broadest, and the side ones worn away internally; two longer red-colored, conical corner teeth in the upper jaw, and four with notched crowns in the mandible. A canal before the eyes. Shields behind the gill-opening. No lateral caudal spines. One species. P. siger.

Genus II. MELICHTHYS, Swain. The front teeth all equal in length standing in a semicircle, the middle ones broad and sharp-edged, like human incisors, as in Pyrodon. Profile arched, with a broader forehead. Large scales at the gill-opening. Tail more or less forked. A canal before the eyes. Two species.

Genus III. NUNICHTHYS, Kaup. Naked furrows on the face; ten rays in the first dorsal. No shields before the gill-opening. One species. N. curvirostris. Fig. 127. (Squamation badly shown.)

Genus IV. CANTHIDERMIUS, Swain. A canal before the eyes. Teeth conical; no lateral caudal spines. Broad forehead; arched profile. Small shields behind the gill-opening. No spines on the tail. Second dorsal and anal fins in the older fish very high; caudal slightly crescentic. Scales in the young very rough, but in the old there are only traces of roughness in the fore stand of the rhombs. One species. C. macrolepis.

Genus V. BALISTES, Linn., Kaup. Canal before the eye. Shields behind the gill-opening. Conical, elongated, cutting teeth; no jutting corner teeth. (a) Two to seven rows of spinules or elevated lines on the tail. Face scaly, without naked streaks. Caudal round or blunt. Four species.

(b) Face naked, above which a row of scales. Two species.

(c) A more or less hollow profile; face scaly. Tail destitute of rows of spinules or raised lines. Second dorsal and anal more or less falcate. Tail more or less forked. Four species.

Genus VI. BALISTAPES, Tilesius. No furrow before the corner of the eye. Two or three rows of spinules on the tail. Traces of ventrals; caudal round or truncated; the second dorsal containing from twenty-three to twenty-seven rays; the anal from twenty to twenty-four. Six species.

Sub-Family II.—MONACANTHINI.

Very small scales which are scabrous, with stiff bristles as densely crowded as the pile of velvet. The point of the pubic bone projects, and is spiny as in the Balistidae; but there is one spine in the first dorsal, and it is large and denticulated; or, if a second spine exists, it is almost imperceptible.

Genus VII. MONACANTHUS, Cuv. (a) In one division the pelvis is very moveable, and is connected to the belly by an extensible dermal; these have often strong spines on the side of the tail. (b) Another division is distinguished by a tuft of coarse bristles on the side of the tail. (c) A third group has the body covered with small pedicellated tubercles. (d) The skin in a fourth group is clothed throughout by slender hairs, which are often branched. (e) And there are some which have none of these distinguishing characters.

Genus VIII. ALUTERUS, Cuv. Body elongated; densely and minutely granular. A single spine in the first dorsal. The pelvic bones entirely concealed beneath the integument, without any bony projection.

Genus IX. TRIACANTHUS, Cuv. Profile subtriangular. The first dorsal placed on one angle, and the tail, which is more slender and tapering than in others of the family, ending in a second, on which is the caudal fin caudal; while the mouth occupies the third. Scales small, rough, with sharp spinules. Ventrales each consisting of a strong rough spine. Pubic bones long, narrow, not projecting, covered with scales like the rest of the integument. Two species. Tr. aculeatus. Tr. striolifer, Cant.

Family II.—OSTRACIONIDE.

Ostraciones, Müll.; Ostracionidae, Cant. Teeth ten or twelve, conical. Lips fleshy. Body mailed in a tuberculated cuirass, or "tegillated quincuncial pavement of dermal scale bones," out of which the lips and teeth, the pectorals, and three vertical fins, together with the tail, protrude. Externally the gill-opening appears as a slit, bordered by a skinny edge, but internally composed of a gill-cover with six branchiostegals. Ventrales and pelvis wanting. Little muscular substance; a large oily liver. Stomach large, membranaceous. Vertebrae mostly coalescent.

Genus I. CIOTONIT, Kaup. (Ostracion a corps quadrangulaire sans épines, Cuv. Rey. An.; Ostracion, Swain.) Nostrils in a pit. No traces of spinules. The completely naked tail destitute of shields or bony rings. Eight species.

Genus II. DOXYPTHERUS, Kaup. (Lactophrys, partim, Swain; Lactophrysi, De Kay.) Nostrils on the points of two small projections. Cuirass four-cornered, with spines above the eyes and on the edges of the belly. Three species.

Genus III. OSTRACION, Linz. (Rhinoconus and Tetroncus, Swain.) Body inclosed in a more or less quadrangular cuirass, with an acute dorsal ridge, which commences near the eyebrow. Nostrils situated in a flat membrane, also one or two prominences without apertures. No bony rings on the tail. Some are without long Classification — Plectognaths.

Genus IV. Aracana, Dr Gray. (Aracanae and Platygasterinae, Swain.) Roundish compressed bodies, with a short tail, which is encompassed by bony plates or rings.

Sub-Genus I. Aracanae, Gray. Having three pairs of flat compressed spines on the dorsal aspect (viz., one over each eye, and two pairs on the edge of the rounded back); one spine on the side, and two or three on the edge of the compressed belly. Six species.

Sub-Genus II. Coropogon, Kaup. Back and belly elevated in the middle; a pair of flat pointed spines on the line which incloses the back; another pair on the border of the belly before the anal. The dorsal plates very rough, with small radiating tubercles. One species, A. unidentata.

Sub-Genus III. Kontocephalus, Kaup. No orbital spines; back concave, with two flat pointed spines on the middle of the dorsal border; border of the belly rough and denticulated with one spine. One species, A. hexagona.

Sub-Genus IV. Anoplocephalus, Kaup. No trace of spines on the orbit. Body compressed, and acutely sloped on the back and belly. No spines developed on the borders of the back or belly. One species, A. lenticularis.

Genus V. Centarchus, Kaup. A large rough tapering acute spine, standing forwards before the large eye; a still longer one pointing backwards from the end of the cuirasse over the caudal, replacing the second dorsal. Two projections from the border of the back between; four from the border of the belly. One species. C. scopus, South Shetland, fig. 18.

Family III.—Diodontidae.

Gymnoderma, Cuv., Müll. Upper and under jaws with which the teeth are incorporated without a medial division, resembling the beak of a parrot; behind the jaw is transversely forked. Skin wholly armed with spines of greater or smaller size. The Diodons and most of the Tetraodon have the power of inflation.

Sub-Family I.—Biodontini.

Genus I. Diodon, Linnaeus. One nostril at the base of a leaf-like cutaneous process, and the other at the point of the same. Spines subulate, long, thin, and sharp pointed, with two radical processes, and capable of erection or depression. Nine species.

Genus II. Dictylichthys, Kaup. Each tentacle two-lobed. No nostril. Spines with three radical processes, which prevent motion; in the middle of the forehead a spine with two processes. One species, D. punctatus.

Genus III. Cycluchthys, Kaup. Two nostrils, one at the base of a tentacle, the other at its point. Spines with three fully developed radical processes, which prevent all motion. Two species.

Genus IV. Cyanichthys, Kaup. Nostrils squeezed together on the forehead in a leaflike tentacle; one aperture on the inner border next the forehead; the other one, which is scarcely perceptible, on the hinder next the eye. Forehead concave, without a spine in the middle. Body armed with short immovable spines. One species, C. corallinus, New Guinea.

Genus V. Chilomycetis, Biber. (Wiegmann Arch. 1847.) Nostrils at the extremity of an extended tentacle. Three large radical processes to the immovable spines. Body flat. In most instances a spine on the forehead, and two or three above the eyes. Three species.

Sub-Family II.—Tetraodontini.

Tetraodon, Linnaeus, Cuv. Upper and under jaws divided by a medial suture, so that they appear to have two teeth above and two below. Spines of the skin much shorter than those of Diodon. The head and tail are generally smooth, but the rest of the body is, with a few exceptions, rendered rough by the presence of minute spines. A species which possesses electric powers is destitute of spines, in obedience to a law ascertained by observation, that none of the electric fishes possess scales or spines.

The following groups are indicated in the Regnum Animalium, and are likely to receive generic names from the first ichthyologist who publishes descriptions of all the species.

Genus I. Tetraodon.

1. Head short, body inflated. 2. Body smooth throughout. 3. The sides only smooth; lateral tubercles. 4. The sides smooth; no lateral tubercles.

II. Head oblong. 1. The sides only smooth. 2. Back and sides smooth; the belly alone rough. III. Back keeled.

Müller has proposed the following sub-genera:

Sub-Genus I. Physogaster, Müll. In the nasal depression a hollow papilla, with a nostril that is not lengthened out into a tube. A dermal keel on the side of the belly from the throat to the tail. T. ocellatus, hemaris.

Sub-Genus II. Chelonodon, Müll. No trace of a nostril, but in place of it a skinny funnel-shaped tentacle.

Sub-Genus III. Chelichthys, Müll. A shorter or longer nostril-tube, and no ventral keel.

Sub-Genus IV. Aracanae, Müll. On each side of the nose solid tentacles, on which the olfactory nerve is expanded; also a muscular ring round the eye, and a kind of eyelid.

Sub-Family III.—Orthagoriscini.

Genus I. Orthagoriscus, Schneider. (Cyphodus, Shaw. Sun-fish.) Jaws of Diodon. Body compressed, generally destitute of spines and incapable of inflation, and with the tail so short and high that the fish appears as if its hinder parts were clipped off. Dorsal and anal both high and pointed, united closely to the caudal. No air-bladder; stomach small, connected directly by the bile-duet. A gelatinous layer immediately under the skin. The abbreviation of the tail is accompanied by a very reduced myelon, looking like a mere ganglionic process of the brain. O. spinosus has pointed tubercles on the body.

Lophobranchii.

Fishes of this order possess an osseous skeleton, and complete and free jaws, but the ultimate divisions of their branchiae, instead of being pectinated, are divided into small tufts, which are ranged by pairs along the branchial arches. The armour in which these fishes are mailed up, gives them a peculiar aspect. The tubular elongated snout is formed by the nasal, vomer, tympanals, preopercula, and sub-opercula. The nasal bone is a short compressed vertical plate.

Notwithstanding the odd and stiff appearance of many of the Sea-horse Fish and other small members of this order, some have prehensile tails (Hippocampus), like those of an American monkey (Cebus), and when kept in vases furnished with slender twigs, to which they can suspend themselves, they form pleasing objects of study. The Hippocampi resemble the Chameleon, in being able to direct one eye backwards and the other forwards, and Professor Lichtenstein observed a circular movement in the water near their gill-openings; on the right side the whirl revolved to the left, and on the left side to the right, the rotation being symmetrical and constant, like that of a Rotifer. The Hippocampi inhabit all parts of the ocean. Others of the order are remarkable for the singularity of their shapes, or of their cutaneous appendages, or for the brilliancy of their colours. The Phyllopteryx foliatus, from the seas between Australia and New Guinea, yields to no fish in the intensity of its red and purple tints, and in the variety of the leaflike lappets that adorn it. A very beautiful drawing, by Bauer, of the recent fish taken on Flinders' voyage is in the possession of Mr Brown.

The most interesting peculiarity, however, in the economy of the Pipe-fishes is that of the males of most species carrying the eggs about with them until they are hatched. Dr Kaup considers that they show an analogy in this respect to the Marsupials, or the Wandering Penguin (Aptenodytes Patagonicus), which transports its solitary egg in a fold of its skin. In some the egg-pouches are on the breast or belly, in others on the tail, or the eggs are merely glued on in rows, and not covered in by membrane. Order VII.—LOPHOBRANCHII, Cuv.

Endo-skeleton partially ossified; exo-skeleton ganoid. Gill tufted; opercular aperture small. Swim-bladder without an air duct. Body almost fleshless, protected by bony rings. In most the male carries the eggs till they are hatched.

Family I.—SOLENOSTOMIDÆ, Kaup.

Breast and belly distinctly separated. Oral aperture at the end of a long, compressed, leaf-like snout. When the gill-plate is raised the whole gills are exposed.

Genus I. SOLENOSTOMUS, Seba, Linn. Snout sharply edged on its dorsal and ventral aspects. A sharp denticulated ridge, passing from the nostrils over the eyes and nostrils, disappears in the acute rostral crest. Back and breast acutely ridged. Pectorals broad and short. Belly down to the caudal fin divided into rings and armed by three longitudinal rows of short spines. First dorsal very long; the second and the anal rudimentary. Egg-pouch of the males formed by the union of the inner borders of the ventrals to the skin of the belly; the females have free ventrals. One species.

Family II.—PEGASIDÆ.

Breast very greatly expanded, much broader than high. Pectoral fin long, with nine or ten firm spine-like rays. Gill-opening lateral; gill-plate flat, depressed to the ventral plane. Mouth inferior, like that of a Star-gazer, at the base of the rostrum. Eyes having three knobbed or spinous rings; breast ring unusually broad, extended between the gill-plates, bipinnate. Ventrales two-rayed, filamentous. Tail flat, quadrangular, spinous. Dorsal and anal occupying two to four rings; caudal ten-rayed.

Genus I. PEGASUS, Linn. Three species.

Family III.—SYNGNATHIDÆ, Kaup; Bonap.

The small gill-opening circular and high up. One dorsal only, near the anus. Form elongated. First dorsal and ventrals wanting; pectorals in some present, in others absent; anal fin very small, in some wholly wanting. The males have egg-pouches varying in position with the genus. Solenognathus and Phyllopteryx have no egg-pouches.

Sub-Family I.—HIPPOCAMPINÆ, Bonap.

Tail generally prehensile at the tip; destitute of a fin. Occiput more or less elevated.

Genus I. HIPPOCAMPS, Cuv. Head more or less elevated posteriorly; an occipital coronet with spines or knobs. Orbits spiny. Pectoral ring with two or three spines. Body with ten to thirteen rings, more or less spiny. Tail-pouch of the male opening at its commencement only; tail prehensile. Eighteen species.

Genus II. AGENTRONCHUS, Kaup. Edge of the back forming one line with the upper tail-ridge. Gill-opening at the point of the occiput. No occurrences either on the body or tail. No coronet. Egg-pouch of the male on the tail as in Hippocampus. One species, A. gracilis.

Genus III. GASTEROTOKUS, Heck. (Syngnathoides, Block; S. lemprieri, Bleek, see Swains.) The lateral lines forming the edges of the expanded belly. No nuchal shield. Tail prehensile. Dorsal standing in a furrow and occupying ten to twelve tail rings. No coronet. One species, G. bicirrhosus.

Genus IV. SOLENOGNATHUS, Swains. Body laterally compressed, higher than broad. Lateral line confluent with the upper angle of the tail, forming an arch. Twenty-two to twenty-six body rings; fifty-five to sixty tail rings. Dorsal fin in a furrow occupying ten to eleven tail rings. Tail prehensile. One species, S. Bardwicki.

Genus V. PHYLLOPTERYX, Swains. Body much compressed. Neck elongated, slender; back arched; belly prominent. Dorsal fin placed on an elevation. Flat denticulated bones, supporting leaf-like cutaneous appendages on the body and tail. Tail finless, not prehensile. One species, Ph. foliatus.

Sub-Family II.—SYNGNATHINÆ, Kaup.

Males possessing a caudal egg-pouch which is open throughout. Tail never prehensile.

Genus I. HALICAMPEUS, Kaup. Snout thin and short, set with three rows of small spines and distinctly separated from the high forehead and elevated spinous orbits. Eyes projecting. Hind-head, nape, and pectoral shield crested; pectoral ring broader than the body. Dorsal fin standing on an elevation formed by three rings only. Body rough-edged, filamentous. One species, H. conspicillatus.

Genus II. TRACHYCEPHALUS, Kaup. Resembling Halicampus, but with a longer head; the snout denticulated on its dorsal aspect only and not extending from the head. Dorsal fin elevated on five or six rings, three of which belong to the body. Pectoral ring no wider than the head; form more elongated than that of Halicampus. Three species.

Genus III. CORYTHOICHTHYS, Kaup. Body tolerably long. Fins small; caudal diminutive. Snout half the length of the elevated head. Orbits large. Dorsal fin commencing in a concavity of the tail over the anus, and not on an elevated base like that of Hippocampus or Trachycephalus. Breath greatest just behind the dorsal. Body varied by light cross-bars. Six species.

Genus IV. ICHTHYOCAMPUS, Kaup. Edges of the concave back and tail running in the same line to the caudal fin. Head short. Tail almost as thick as the body, suddenly pointed at the base of the rudimentary caudal; more tetragonal than Corythoichthys. Three species.

Genus V. SYNGNATHUS, Linn. No spines on the straight cylindrical snout. Body pentagonal. Dorsal fin on the plane of the back, not on an elevated base. Upper border of the back never in the same line with that of the tail; upper border of the tail either continuous with the lateral line or interrupted where that line terminates. Dorsal surface of the body flat or flatly concave, and never much compressed or bent into an arch. Body rings never amounting to twenty-four or twenty-seven. Twenty-two species.

Genus VI. LEPTONOTUS, Kaup. In the females the body is much compressed, and the back is acute like the edge of a knife. Belly also acute, and in old fish the height of the body is five times its breadth, but in the young the body is not so high. Dorsal profile suddenly rising behind the pectoral fin. Tail nearly twice the length of the body. Two species.

Genus VII. SIFTONOTUS, Rafin. Pectoral ring cleft on its ventral aspect in the middle of its length. Long and pretty thick, with a greatly compressed snout that projects evenly in the plane of the forehead. Five species.

Genus VIII. LEPTOICHTHYS, Kaup. Snout very long, thin, and much compressed; extended in the same plane with the finely shagreened head. Body unusually elongated; hexagonal, with a flat back and belly without intermediate scales. All the fins large, especially the caudal. Gill-opening longer than usual. One species, L. familiaris.

Genus IX. STIOMATOPHORA, Kaup. A pectoral fin; no caudal. Snout acutely ridged; prolonged. Mouth turned upwards. Anal fin three-rayed. Two species.

Sub-Family III.—DOXYRHAMPHINÆ, Kaup.

Males with their egg-pouch on the breast and belly, not on the tail.

Genus I. DOXYRHAMPHUS, Kaup. No pits on the nuchal shield. Rows of spines on the snout, and two projections on its under part. All the angles of the body serrated. The border of the egg-pouch developing two tender membranes which completely cover the eggs. Tail shorter than the body. One species, D. excisus.

Genus II. CORYTHOICHTHYS, Kaup. Body short; arched above and below. Snout without spines or projections beneath; slender and rising upwards near the mouth. Lateral line unusually projecting, and uniting with the under edge of the tail. No pits on the small nuchal shield. Egg-pouches furnished with a membrane. Fins not much developed. One species, Ck. Valenciennii.

Genus III. DOXYRHAMPHUS, Heck. Snout elongated, compressed, spineless. Two long thin bones near the gill-cover, joining the occiput, and bounding a slit-like opening. Tail quadrangular, shorter than the body; hexangular to the end of the dorsal. Nine species.

Genus IV. HEMITHYACUS, Kaup. Snout exceeding the body in length, with a two-edged border on its dorsal aspect, rounded beneath. Body compressed. Egg-pouch of the males reaching from the pectoral ring to the anus. One species, H. leucops. The eggs distributed in rows on the breast and belly of the males, not covered by membrane.

Genus I. Microphis, Kaup. Body heptangular, composed of very rough rings, and of equal thickness to the setting on of the elongated tail. Five fins. Two species.

Genus II. Nerophis, Rafin. Neither pectoral nor anal fin. Body cylindrical without distinct edges. Nine species.

GANOIDAE.

Müller remarks that the difference between Cycloid and Ctenoid scales is slight, and its systematic application is consequently confined to narrow limits; but that the case is very different with regard to Ganoid scales. These are bony, generally of a rhombic form or quadrangular, seldom rounded in outline or imbricated in position, and their surface is always smooth and coated with a layer of enamel; they are generally arranged in oblique rows, those in each row being usually united to one another by a hinge-like prolongation of the anterior angle. The Ganoid scales are imbedded, like ordinary scales, in depressions of the skin; but the epidermis is extremely thin, and adheres closely, so as to appear wanting. This is the case in Polypterus, but in Lepidosteus the epidermal covering is more evident. The living Ganoids have completely bony skeletons, but in the fossil ones many have had skeletons soft and cartilaginous like those of the Sturgeons. Müller sums up the Ganoid character in the following words:—Fishes provided with either tabular and angular or round enamelled scales, or with bony plates, or a perfectly naked skin. Their fins frequently, but not always covered on their anterior border with a single or double row of spiny plates or laminae (fulcra); their caudal fin sometimes involving in its upper fold the extremity of the vertebral column, which may continue to the end of that fold; their nasal apertures double; their gills free and lying in an opercular cavity, as in the osseous fishes. Several have an accessory organ in form of an opercular gill, which is different from a pseudobranchia, and may occur at the same time with it; many have also blowing holes like the Plagiostomi. They have several valves in the arterial trunk, like the latter; their ova are conveyed from the abdominal cavity by tubes; their optic nerves do not decussate, but merely cohere laterally; their intestine often contains a spiral valve, like the Plagiostomi; they have a swimming bladder with an air-tube, like many osseous fishes; their skeleton is either bony or partly cartilaginous; and their ventral fins are abdominal. If, however, reference be made to the absolute characters only which are never absent, the Ganoids are fishes with numerous valves in the arterial trunk, no decussation of the optic nerves, free gills and opercula, and with abdominal central fins.

Agassiz included the Selonodermi, Gymnondontes, Loricarii, Siluridae, and Lophobranchii among the Ganoids; but, according to Müller, all these groups belong to the ordinary osseous series, and have only two valves in the arterial trunk. The existence of an accessory opercular gill is a character of the Ganoids and Sturgeons, and does not occur in other osseous fishes. Müller further observes that the Ganoids resemble the Selachii in having a thymus gland. This organ was described by Dr Simon as it exists in the Sturgeons, and it is found in the same position in Polypterus and Lepidosteus; that is, between the anterior basibranchials and the sternohyoid muscles. It was considered by Retzius to be a sublingual salivary gland, but it is a vasoganglion; and Professor Owen is of opinion that Dr Simon's view of its homology with the thymus gland is more in accordance with its nature; but he also thinks that Dr Simon has described as a thymus gland in various osseous fishes the same parts which Müller has called pseudobranchiae in those fishes.

Characters distinguishing the Polypteri from Lepidosteii exist in the solitary arrangement of the rays of the vertical fins, the want of accessory gills, and the incompleteness of the fourth gill, which has only one layer of leaflets, and wants also the slit behind it. There is only one pancreatic cæcum, whereas the Lepidosteii have many; both have muscular coats to the air-bladder, but in the Lepidosteii that viscus is cellular, and the muscular fibres are in bundles between the folds of the bladder. The air-tube or trachea in the Lepidosteii is wide, and opens through the dorsal wall of the oesophagus, its orifice being regulated by a sphincter muscle. But the Polypteri differ from all other known fishes in the air-duct entering the beginning of the oesophagus or gullet on its ventral side. The arteries of the swim-bladder of the Lepidosteii arise in great numbers from the aorta, and the veins empty themselves into the two subvertebral veins. In this case, therefore, the cellular swim-bladder cannot be considered as a lung. In the Polypteri the artery of each of the two air-bladders is formed by the union of the bloodvessels coming from the last gill, and therefore carrying blood already oxygenized. The Lepidosteii have saciform ovaries, with oviducts issuing from the middles of the sacs. These fish are by no means rare in the North American waters, and a few years ago the researches of Agassiz had raised the number described to ten. It is probable that since then more have been discovered; as he was of opinion, from what he had then observed, that every separate river, basin, or watershed, had its peculiar species. The Lepidosteii frequent shallow, reedy, or grassy places, and bask in the sun like Pikes.

Polypterus is an African genus. Dr Baikie, in his late ascent of the Tchadde, obtained specimens of what he thinks will prove to be a new species, but he has not yet been able to compare it with the one that exists in the Senegal. The thymus gland is double in Polypterus; and the spiral intestine valve, which in Lepidosteus is but slightly developed, attains its maximum size in this genus, extending upwards to the entrance of the bile-duct.

Amia is a genus of American fishes, existing in the fresh waters of almost all parts of the United States, but chiefly abounding in the muddy streams and lakes of Georgia and Florida. At New Orleans the Amia are named "Mud-fish." M. Valenciennes describes the genus among the Malacopterygians, and says that it exhibits numerous affinities with other families of that order, agreeing with the Cyprinidae in the simplicity of the intestinal canal and want of pyloric cæca, though no Cyprinoid resembles it in having a spiral valve in the intestine. Like Elops and Megalops, it possesses a sublingual buckler. By the large size of its suborbitars, it is allied to Erythrinus; in its dentition, and in the structure of its ovaries, it has marked connections with the Salmonoid fishes; lastly, in its general aspect, the length of the dorsal, the form of the scales, and in the length and flexibility of the body, it evinces close similarity to Ophicephalus. These remarks of M. Valenciennes are enough to show that ichthyologists were at a loss to find the proper place of this genus when Dr Vogt, in 1845, discovered it to be a Ganoid, for he found in its arterial trunk two oblique rows of five or six valves each, and the arterial trunk itself covered with a well-defined layer of muscular fibres, as in other Ganoids. It has, moreover, a spiral valve of several turns in the intestine, though it does not ascend so high up as in Polypterus. But the scales of Amia are not Ganoid, and have not the slightest resemblance to those of that genus or of Lepidosteus; and from this Müller infers that the structure of the scales is not to be trusted as an ordinal character. The scales of Amia are not osseous plates; they are flexible and rounded, and destitute of enamel. Similar scales belong to the fossil Megalurus and Leptolepis, which are considered by Agassiz to be Ganoids. In habit Amia resembles the osseous fishes rather than the Ganoids. As Amia agrees with the other Ganoids in the valves and muscularity of the arterial trunk, and in the spiral intestinal valve, Müller infers that it will be found also to possess a chiasma of the optic nerves (no decussation), a thymus gland, and an uncleft retina. He concludes by saying that it cannot be referred either to the Lepidosteini or Polypterini, being separated from the former by the absence of fulcrum, and from the latter by not possessing the dorsal polypteryx; and he therefore regards it as the living representative of a peculiar family of Ganoids, and finds analogous genera in the fossil Megalurus, Leptolepis, Thrissops, and their allies. All of these have soft scales, an osseous vertebral column, and a similarity in form of body and structure of fins. Questions of such interest to ichthyologists have doubtless long ago been solved by Agassiz, who has such ready access to many species of Amia, but the results of his investigations have not reached us. Cuvier compared the air-bladder of Amia to the lung of a reptile on account of its great cellular subdivision; and in his list of affinities or analogies above quoted, M. Valenciennes might have added the similarity of the air-bladder of the Amia to those of Erythrinus, or of the Siluroid Bagrus, which have that viscus subdivided by transverse septa.

The Sturgeons are very abundant in the rivers of Siberia which flow to the southward, and no less so on both sides of North America. They do not inhabit any of the rivers of that country which flow into the Arctic Sea, and consequently are not found to the N. of the watersheds between the 53rd and 54th parallels of latitude, where the mean temperature of the year is about 33° of Fahrenheit's scale. They seldom enter clear cold streams, but in the season ascend the muddy rivers in vast numbers, so that many populous native tribes subsist wholly on the Sturgeon fishery during the summer. In most localities two forms are readily recognised by the comparative length and acuteness, and shortness and bluntness, of their snouts; but every watershed has its own species, varying in the osseous shields, positions of the rostral barbels, form of the tail, fins, and other characters.

ORDER VIII.—GANOIDEI, Müll.

Endo-skeleton in some osseous; in some cartilaginous; in some partly osseous partly cartilaginous; exo-skeleton ganoid. Fins usually with the first ray a strong spine. A swim-bladder and air-bladder. Numerous valves in the arterial trunk. No decussation of the optic nerves. Free gills and opercula, and abdominal ventral fins.

FAMILY I.—LEPIDOSTEIDÆ.

Lepidosteini, Müll. Upper jaw composed of several pieces; the vomer divided in two by a median cleft; the basiphenoid is confluent with the basioccipital; the nasal bone dentiferous; the mandible composed of as many pieces as in Reptiles; the vertebrae articulated by ball and socket; the olfactory organ situated at the extremity of the greatly elongated jaw, contains the ordinary nasal folds which are arranged simply; a respiratory opercular gill is present as well as a pseudobranch, but no blowing hole. The Willisian arches have the perfect bilobate structure, and behind the last arch there is a hyoid bone there exists, as usual, a fissure. Branchiostegals three; the membrane passing from side to side like a mantle, and undivided. Anterior edge of all the fins protected by two rows of spinous scales; rays all articulated; caudal fin abruptly truncate, its rays inserted partly at the extremity of the vertebral column, partly beneath it. Stomach not cecal; several pancreatic ceca; no spiral valve in the intestine; swim-bladder cellular, containing trabeculae connective between the cell divisions, and opening by a long slit into the upper part of the throat.

Genus I. Lepidosteus, Lacép. An elongated snout varying in breadth in different species, formed of the premaxillaries, maxillaries, palatines, nasal, and vomer; mandible equal to its length; both covered on their surfaces with rudiform teeth and bordered by a row of long pointed ones. Ten species, American.

FAMILY II.—POLYPTERIDÆ.

Polypterini, Müll. The upper jaw is not divided into pieces, the vomer is single, and the mandible and skull generally are constructed as in other osseous fishes. A labial cartilage exists at the corner of the mouth, supporting the upper and under lips. The fourth gill is only unifoliate, and there is no slit behind it; the opercular gill is wanting, and no pseudobranchia ever occurs; but there is a blowing hole on each side, covered by an osseous valve. The inferior pharyngeal bones are wanting. A series of separate fins extends along the back, each consisting of a spine and a plume of articulated rays behind it. The rounded caudal and the anal are composed of jointed rays, which in the former are inserted above as well as below the spines; the pectoral has a somewhat elongated Emily line. The nostrils are more complicated than in any other fish. In a large variety there is a labyrinth of five nasal passages, each with a gill-like arrangement of folds; anterior nostril prolonged into a membranous pipe; the posterior has a small cleft anterior to the eye. The stomach is cecal, and there is a pancreatic cecum. The intestine contains a spiral valve; swim-bladder double, consisting of two sacs differing in length, and opening into a short common cavity that communicates with the ventral floor of the throat by a long fissure.

Genus I. Polypterus, Geoff. Three species, Nile, Senegal, Tchadha.

FAMILY III.—AMIIDÆ.

Genus I. Amia, Linn. Excepting in the absence of lingual teeth, the mouth of an Amia is that of a Trout. Head covered with a very thin mucous skin, easily removed, and then the naked cranium, supratemporals, suborbital scale bones, and operculum appear as sculptured bony plates. The sublingual bone is naked and furrowed. Upper part of the snout smooth and fleshy; inferior lip thin and thick. Cheek almost wholly covered by the suborbitals. Each nostril with two openings, the anterior one a projecting tube like a barbel, the posterior one an aperture near the eye. Upper arch of the mouth formed by small premaxillaries and large moveable maxillaries. Teeth on the jaws; vomer, pterygoids, palatines, and large double branches of the mandible, mostly in rows of conical teeth, with small tessellated patches behind; on the pharyngeals the teeth are cardiform, and rough granular patches exist on the internal face of the operculum, a singular piece of structure which M. Valenciennes regards as the rudiment of an accessory branchia. The tongue is elongate, thick and fleshy. Large gill-openings. Branchiostegals eleven to twelve; broad and flat. Scales of the body thick, but osseous. Caudal coming farther forward on the upper edge of the tail than in the sturgeonian; dorsal long; anal small. Stomach cecal, with a large pyloric valve. No pancreatic ceca; a very large air-bladder, forked anteriorly, and communicating with the oesophagus; cellular within, in the upper and lateral parts, but not below. Ova dropping into the cavity of the abdomen. Fresh waters of America. Ten species.

FAMILY IV.—STURIONIDÆ.

Sturiones, Sturionides et Chondropterygii, Abramites liber, Cuv. Chondrostei, Müll.; Accipenserida, Müll.; Acipenseridae, Bonap. Skeleton partly cartilaginous, vertebral column a soft chord instead of vertebrae.

Genus I. Accipenser, Linn. Form squaloid. Body more or less protected by rows of bony shields. Head enframed. Mouth beneath the snout, small and toothless. The premaxillaries form the anterior inferior border of the upper jaw; the maxillary is a small oval plate articulating to the outer process of the premaxillary, and by its inner end to its inner posterior side to the palatine bone. The mandible consists principally of a single bony limb, which is joined to its fellow at the symphysis; its joint is formed by a trochlear cartilage attached to the pterygoid process of the palatine. The mouth thus formed is more protractile than that of the Sharks. Rostral barbels on the ventral aspect. Labyrinth in form and position resembling that of the osseous fishes. No vestige of an external auditory opening. An aperture behind the temples conducts merely to the gills. Dorsal and anal opposite, behind the ventrals; caudal encircling the extremity of the spinal column, the upper lobe the principal one, a smaller and shorter one being a spiral intestinal valve, and conglomerated pancreas as in the Sharks; a very large swim-bladder communicating with the oesophagus by a large hole.

Genus II. Polyodon, Lacép. Spatulina, Shaw. Pikesucker. Scopelichthys. Technically distinguished from Accipenser by the naked skin destitute of bony shields; recognisable at once by the enormous leaf-like expansion of the snout. In general form Sturgeons, but the gill-openings are larger, and the membranous tip of the gill-flap reaches the middle of the body. Mouth very wide, with a multitude of little teeth. A gelatinous chord in the spine like that of the Lamprey. A spiral intestinal valve; pancreas partially divided into ceca; an air-bladder. Müller says that the opercula are absent in Polyodon. (Osteol. der Myxine.)

Its flesh is not much esteemed, as it is soft, insipid, and difficult of digestion.

The Bream (Leuciscus brama, Valenc.) is common in slow-flowing rivers and lakes in most European countries. It sometimes attains 2½ feet in length, but its ordinary dimensions may be stated to be about 1 foot. Worms, conger, and aquatic plants are its usual food; but like many allied species, it often swallows mud, which renders its flesh unsavoury. "There exists in the River Trent, in the neighbourhood of Newark, two species or varieties of Bream. The common Bream is known there by the name of Carp Bream, from its yellow colour, and has been taken of nearly eight pounds weight. The other species or variety, which I believe to be a nondescript, never exceeds a pound in weight. It is of a silvery hue, and goes by the name of White Bream."

Leuciscus rutilus (Valenc.) is the Gardon of French fishermen, and the Rödskalle (Red-scale), or Redfish (Red-

Röthauge, but in general it is called in that country Roche, an appellation evidently identical with its English one.

The Clun, named in Cumberland Skelly, is a well-known English fish, and has received its northern appellation (quasi Scaly) from the size of its scales.

English ichthyologists have all given it the specific name of cephalus, but M. Valenciennes remarks that the term cephalus was applied by Linnæus to an assemblage of erythrinus with the tenth species of Artedi, which itself comprehends several European Cyprini. He therefore employs the specific name of Jese, also Linnæan, to denote the Clun of England, which is the Jeuling or Brat-fisch of the Danube, and the Jese or Jese of the Oder.

Leuc. phoxinus (common minnow) is familiar to all. It is the smallest species of the genus found in Europe, the greatest length which it attains seldom exceeding 3 inches. It first makes its appearance in March, and disappears in October, passing the winter beneath the mud. It is well known to be a gregarious species, and small shoals are to be found in almost every shallow stream, especially in clear weather, as they seem to delight in warmth and sunshine. They usually spawn in the month of June, but their ova are often found at a much later period. The flesh of the minnow is delicate and well-flavoured, but its size is too small to admit of its being of much value as an article of food. It is principally used as a bait for the capture of larger kinds.

Family XVII.—Cyprinidae.

Cyprinoidæ, Agass. A small, soft, toothless oral orifice, the upper half formed by the pre-maxillaries only, the maxillaries lying behind them; no teeth except on the bones encircling the posterior aperture of the mouth; under pharyngeals armed with one large tooth; upper pharyngeal wanting. On the base of the cranium, or basi-occipital, and opposed to the under pharyngeals, there is a projecting process covered for the most part by a horny plate. Most have scales (Anableps, Heck., is an exception). No adipose fin. Siphonal stomach; no pancreatic ceca; swim-bladder in most divided into a fore and hinder part, and connected with the acoustic organs by a chain of osicles. The presence or absence of supplementary branchiae varies with the genera. Cobitis and Acanthobranchus, having bony coverings to the swim-bladder, ally themselves to the other Cyprinidae, as Ctenias, Heterobranchus, Heteropneustus, and Classificat. Agonidae, which have a bony capsule to the swim-bladder, do to the tion—Ma. Siluridae. This structure does not exist in all the Cyprinidae allied to Cobitis; and in Schizodon there is a thick-skinned swim-bladder behind the enlargement of the vertebrae. Both M. Agassiz and M. Valenciennes restrict the genus Cobitis to the species which want teeth.

This great family, as now restricted, comprises fresh-water fishes only. It contains a great number of species in all parts of the world; and no one has as yet made a satisfactory arrangement of them and characterized the genera so that they can be easily dis- tinguished. We follow M. Valenciennes in the primary grouping.

GENUS I. CYPRINUS, Lacép. A long dorsal, with three ridges gent rays, the third and longest one being often denticulated on its hind edge, resembling the rays of some Siluridae; anal with two strong solid rays. The under pharyngeal teeth are five, one being very large, with curved, seemingly concentric edges, and three somewhat wavy parallel enamelled ridges, separated into two by a longitudinal furrow; farther back on each side of this principal tooth there are two others, not half as big, having flat and worn crowns; before the large mesial tooth there is another rounded one, without concentric; and behind all, a fifth very small tooth. This is the dentition of the Cyprinus carpio, or common Carp, but the number of teeth varies with the species. Body thick or more or less high, with flat sides, and thick scales. One genus (Cyprinus) has small barbels at the corners of the mouth; another (Cyprinodon) (Cyprinodon, Fitting.) Twenty species in the Histoire des Poissons.

GENUS II. BARBUS, Flem. Body fusiform. Dorsal short, with three small simple rays in front, and a fourth very strong one, like that of Cyprinus, sometimes denticulated, in other species smooth; two barbels in front of the maxillary joint, and two labial ones from the corners of the mouth; four in all. Pharyngeal teeth coni- cal, elongated, and a little curved. Sixty-two species, subdivided by the smooth or denticulated rays, and the projecting or non- elongated barbels.

GENUS III. LABEOIDES, Hipp. Body elongated. Lips thick, the inferior one having a single symphyal thick barbel, making five barbels in all, including the pair of maxillary, and pair of labial ones. A firm ray not denticulated in the dorsal, and a short anal. Three species.

GENUS IV. SCHIZOTHORAX, Heck. Cyprinoids with a maxillary and labial barbel on each side. Dorsal and anal short; three dorsal ossous rays, the third one denticulated. Scales small; a cutaneous fold on the posterior part of the belly, clothed with larger scales, concealing the anus and greater part of the base of the anal, like a slit. Many various, giving rise to subdivisions founded on its several kinds of form. Ten species.

GENUS V. RACONIS, McClell. Differs from Schizothorax in the projecting maxillaries; the premaxillaries form a moveable append- age to the mouth.

GENUS VI. ORINIS, McClell. Head fleaky; mouth vertical; mandible shorter than the premaxillaries; snout muscular and projecting. Dorsal preceded by a serrated ray. Scales small. In- testinal tube five or six times as long as the body, capacious. Mountain fish.

GENUS VII. SCHIZOYGE, Heck. Separated from Schizothorax, by the acute cartilaginous-edged mandible, and the bony ray of the dorsal, standing either before or above the ventrals.

GENUS VIII. DANIELIS, Valenc. Remarkable for the length of the dorsal, without the anterior serrate rays, differing in the latter character only from the dorsal of Cyprinus. Another peculiar char- acter is the conical papilla on the border of the upper lip, resem- bling small teeth; a labial and a maxillary barbel beneath the mouth.

GENUS IX. LEBEOCHILUS, Bleek. Between Lebeo and Barbus. Border of the mouth threefold; lips smooth, not fringed, the inferior one forming a square fleaky lobe; snout prominent, fleaky. Four maxillary and labial barbels. No toothed dorsal or anal spine.

Lebeo falsus, Cuv. and Valenc., and three others.

GENUS X. CROSSOCHEILUS, Bleek. Mouth inferior, with a three- fold border, the orifice a parallelogram; lips crenated or fimbriated with papillae; snout fleaky, very prominent, with two barbels. No toothed dorsal or anal spine. Lebeo oblongus, Cuv. and Valenc.

GENUS XI. DEVARIO, Heck. Pharyngeal teeth knife-edged; mouth subinferior; lips round. Two barbels at the corners of the mouth, or none. Dorsal and anal fins elongated, each with a smooth ossous ray having a flexible tip. Intestine between four and five times the length of the body. Seven species.

GENUS XII. NURIA, Valenc. Cyprinoids with the dorsal fin back like that of a Pike, short and without spines. No maxillary barbels, but a pair of labial barbels at each corner of the mouth, keeping up the number four. Thin lips. Two species.

GENUS XIII. ROBITA, Valenc. Four barbels round the mouth; thick fleaky lips, with their edges fringed more or less. A thick fold of skin inclosing the lips, forming above a sort of muzzle; and below a veil covering the closed mouth. Premaxillaries small,

and attached to beneath the point of the nasal, so that the mouth is Classificat—protracted like a cupping-glass. When the lips are retracted they retire within the mouth like a fold of skin. Intestinal canal very long. Herbivorous. Twenty-three species.

GENUS XIV. CARPOTA, Valenc. Intermediate between Barbus and Cobitis, and containing species with a barbel at each angle of the mouth, or two in all; some with a denticulated ray in the dor- sal; others with a solid ray, not denticulated; and a third group again with the ray soft.

GENUS XV. CIRRHINUS, Cuv. Maxillary barbels, two in all; no labial ones. A moderate-sized dorsal without spines, all the rays being flexible. Lips thin; snout not elongated beyond the mouth.

GENUS XVI. GORIO, Cuv. Dorsal and anal short, without spines. Barbels labial, i.e., at the corners of the mouth. Pharyngeal teeth conical, slightly curved at the tip, and in two rows.

GENUS XVII. TINCA, Cuv. Thick and broad body, covered with small scales, and a labial barbel at each side of the mouth. Pha- ryngeal teeth clubbed.

GENUS XVIII. LABEO, Cuv. Snout thick and fleaky, projecting over the mouth, which is furnished with triple lips, one emanating from the preorbital and extending over the two others, a second from the maxillary, and a third the true lip below, detached so as to make a mandibular velum; a small barbel at the corner of the snout. Anterior dorsal rays slender and simple, the others branching and very flexible. The Laboidea, therefore, are Cyprinoids, with the dorsal of variable shape. These fish belong entirely to the old world.

Heckel makes a group of the Cyprinoids which have three double or triple rows of lips, which he names Pseudobarbi; and includes in it the genera Labo, Eohilo, and three characterized by himself, Ptygonathus, Discomyzus, and Cyrene.

The following genera want barbels.

GENUS XIX. LEUCICUS, Valenc. The length of the anal has been given as a distinctive character of Abramis, and its short- ness of Leuciscus; but M. Valenciennes, finding that there was an important group in the length of this fin among the species, ranges them all under Leuciscus, considering generally as mere specific characters those derived from the form of the pharyngeal teeth by which Agassiz, Bonaparte, and Heckel have sought to de- fine the numerous groups they have formed. Leuciscus is to be known, then, chiefly by negative characters. Short dorsal without spines; anal short or long, also without spines, and no particular conformation of the lips. In the Histoire des Poissons one hundred and forty species are described in eleven groups.

The following genera have been characterized by the authors whose names are given, and Dr. McClelland, in his account of the Indian Cyprinids, has named and described numerous groups, but a revision of the entire family is needed before the proper places of these various genera can be found. The Prince of Mu- sigrano's Catalogo Metodico dei Cyprinidi d'Europa may be con- sulted with advantage by those who wish to master the arrange- ment of the Cyprinoids.

GENUS XX. GILA, Baird and Girard. Body fusiform, com- pressed, with the back more or less arched in the older fish. Head depressed, uncommonly small, its upper profile concave; snout elongated; no barbels. Pharyngeal teeth oblique, compressed in two rows, hooked at the point. Four gills.

GENUS XXI. CHONDrostoma, Agass. A horny cartilaginous plate covering the lower lip, easily detached in dead fish, but leav- ing the soft bone on which it was implanted. Some have labial barbels, and others maxillary barbels, and there is much variety in the pharyngeal dentition. Ten species.

GENUS XXII. CATLA, Agass. Maxillaries dilated, and forming thin laminae, which advance over the equally thin premaxillaries, forming a snout shorter than the mandible, whose limits are like- wise so dilated as to encase one another, and give a prominent, rounded form to the throat; when depressed the lower jaw looks like the bowl of a large spoon. The lower lips are thick and fleshy, but without barbels; and the branchial rakers are long and hair-like, and very flexible, resembling the same organs of a Clu- peoid rather than of a Cyprinoid. One species.

GENUS XXIII. BARBODONDA, Heck. Mouth small; no barbels. Suborbital scale-bones covering the cheeks. Short base of the dorsal fin standing over the interval between the ventrals and longer anal; ventrals with seven divided rays; lateral line much decurved.

GENUS XXIV. CATASTOMUS, Forster, Lesu. Resembling the European Barbel in general form, but having neither maxillary nor labial barbels, and no bony or denticulated rays in the dorsal. Mouth under the snout, without teeth; lips large, lobed, and variously This very large family brings up the rear of the Malacoptygians which have an air-tube to their swim-bladder (Physostomati, Moll.), and in fact some of the rays of their fins are firmer, stouter, and nearly as hard as the spinous rays of the Acanthopteri. It is indeed only when the joints of Malacoptygian rays have much length that they have great flexibility; and there are gradations of abbreviation and consolidation until the joints become nearly or wholly obsolete, and the rays as pungent as the first rays of the pectorals and dorsal of the Siluroids, which are powerful bony weapons, often strongly toothed or serrated. Yet these strong bones (which, in the fossil state, are named Ichthyodorulites) frequently betray their compound nature by their tips being soft, flexible, and jointed.

There are many peculiarities in the skeleton of the Siluroids, arising from the absence of some bones, and the greater development of others. The cavity of the cranium is not open laterally, as in most osseous fishes, but is closed, as in the Cyprinidae, by the orbitosphenoids and the ethmoid that unite with the prefrontals, carrying forward the cranial cavity to the nasal bone without leaving a membranous septum between the orbits. The petrosal is often wanting in fishes of this family, and some do not possess even the parietal. But the supraoccipital is greatly developed, and in many, the suprascapula is united by suture to the sides of the cranium. In numerous members of the family the skull is enlarged, posteriorly, to form a kind of helmet which spreads over the nape; the lateral angles of this production are formed by the suprascapulae, augmented and fixed by suture, and the median part is the extension of the supraoccipital, which stretches out to touch or even articulate with the osseous expansions of the anterior interneurals. The supraoccipital, which is generally very large, articulates anteriorly with the frontal, and passing backwards between the postfrontals, the parietals, the mastoids, and the suprascapulae, goes past them all on the nape. The mastoids interpose between the postfrontals and the parietals, so as to come in contact with the supraoccipital, and the parietals, but little developed, are pressed to the back part of the cranium, and in some instances wholly disappear.

The suprascapula most frequently unites to the mastoid by an immovable suture, which includes the parietal when that bone is present, and extends even to the supraoccipital; it gives out besides two processes, one of them resting on the exoccipital and basioccipital, or wedging itself between them, and the other going to the first vertebra; sometimes a plate from the exoccipital supports that same vertebra. This vertebra, though it presents a pretty continuous centrum beneath, is in reality composed of three or four coalescent vertebrae, as we ascertain by its diaphyses by the circular elevations of the neural canal and by the holes for the exit of the pairs of spinal nerves. There is great variety in the development of the various processes of the bones we have mentioned, and there is no less in the magnitude and connexions of the first three interneurals.

In general, in the species which have a strong dorsal spine, the second and third interneurals unite to form a single plate, named in the Histoire des Poissons the "buckler," and which is usually more or less crescentic in shape; the great spine is articulated to the third interneural, and there is only the vestige of a spine on the second interneural in form of a small oval bone, forked below, whose function is to act as a bolt or fulcrum to the great spine when the fish wishes to use it as an offensive weapon. The great spine itself is joined by a ring to a second spine which belongs to the third interneural. This articulation by ring exists in Lophius and a few other fishes not of this family.

The first interneural does not carry a ray, and it varies much in the species whose helmet or casque is continuous with the buckler, as in many of the Bagri and Pimelodes. In these cases the supraoccipital, extending backwards, conceals the first interneural, passing over it to touch with its point the buckler formed by the second and third interneurals. In other instances, as in Synodontis and Auchenipterus, the supraoccipital and second interneural, forking and expanding, inclose and join themselves o the first interneural, but leave a larger or smaller space in the middle of the nuchal armour which they contribute to form. When the point of the supraoccipital does not reach quite to the second interneural, the first interneural remains free from connection, and occasionally shows us a narrow plate, interposed between the other two; in such a case the helmet is not continuous with the buckler. The neural spines of the coalescent centra which form the apparently single first vertebra, concur also in sustaining the nuchal plate-armour and the first great dorsal spine; they carry the interneurals, are joined to them by suture, and one of them is often inclined towards the occiput to assist in sustaining the head; in fact, this part of the skeleton is constructed to give firm mutual support.

The scapular chain of the Siluroids is also formed to give the resistance to the strong weapon with which it is armed. The suprascapula, as we have said above, is often united by suture to the cranium, and it obtains support below by one or two processes that are fixed on the basioccipitals and exoccipitals, and upon the diaphysis of the first vertebra: no scapula is ever present; it is between the two arms of the suprascapula that the top of the coracoid is fixed. In most osseous fishes the coracoid completes the lower key of the scapular arch in joining its fellow by suture or synchondrosis without the intervention of the radius; but in the Siluroids the radius descends to take part in this joint, and sometimes even to occupy the half of the suture, which is not unfrequently constructed of very deep interlocking serratures. The solidity of this base of the pectoral spine is further augmented by the intimate union of the radius and ulna, which often extends to junction by suture, or even to coalescence; and these bones, moreover, give off two bony arches,—the first, a slender one arising from the salient edge of the radius near the pectoral fin, and going to the interior face of the ascending branch of the coracoid; this process is analogous to one in the Cyprinidae where it is a separate bone; the second and broader supplementary arch does not exist in the Cyprinidae, and is often perforated by a large hole; it also emanates from the same salient edge of the radius, but proceeds in an opposite direction to the inferior edge of the coracoid, a little before the insertion of the pectoral spine. These two arches give attachments to the muscles that move this spine; in the Synodontes and many Bagri, the upper arch remains in a cartilaginous or ligamentous condition; while in Malapterurus it is the lower arch that does not ossify, but both are fully formed in the Siluri and many other Siluroids more closely allied to that typical genus. The epicoracoid is also wanting in the Siluroids (Nos. 49, 50, figs. 10 and 15). The pterygoid and entopterygoid (25, 24, id.), are reduced to a single bone, and so are the epitympanic and pretympanic; the mesotympanic (31) is wholly wanting, and the palatine is merely a slender cylindrical bone. The subperculum is likewise constantly absent in all the Siluroids. This long anatomical detail has been extracted from the Histoire des Poissons, because without it descriptions of this peculiar and interesting family could not have been understood.

The Siluroids have no true scales, though some of them (Doros) have the lateral line armed with bony plates, and in others (Callichtys) these biserial plates are developed so as to incase the entire body. There are also varieties of external structure similar to those which occur in other large families of fishes, such as the different positions of the fins, and even the entire absence of certain of these members in some groups. Many of the Siluroids are fresh-water fishes which attain a great size, and they are what are called ground fishes, and remain habitually at the bottom of the pieces of water that they inhabit. In the genus Silurus, as well as in Pimelodus, the choroid vasoganglia and pseudobranchiae are both absent. Silurus glanis, L., is the largest of European fresh-water fishes, and the only one of this extensive genus inhabiting the Continent. It is smooth, greenish black, spotted with black above, and yellowish-white beneath. The head is large, with six barbels. It sometimes attains the length of 12 or 15 feet, and the weight of 300 or 400 lbs. As this creature is somewhat unwieldy in its motions, it does not pursue its prey, which consists of small fishes, but lies concealed among the mud, and seizes such unwary stragglers as happen to come within reach. The fishermen of the Spree say that they always take the largest fish of this kind in a thunder-storm. Insects are the best bait for the younger ones. It has occasionally been observed in the sea, but always near the mouths of rivers. Gronovius and Temminck both authenticate its occasional capture in the salt water. The flesh is fat and sweet, and its lard has been employed in some places as a substitute for that of the hog. Sir Robert Sibbald, at the conclusion of his list of river fishes, adds Silurus sice Glanis; from which it has been inferred that this gigantic species may, at one period, have inhabited the Scottish rivers; but this fish is a stranger to the waters of France, Spain, and Italy, as well as to England, which furnishes a strong argument against the conclusion that has been drawn from the sentence in Sibbald, unsupported as it is by any reference to accounts of its capture in Scotland. In fact, it is in the western European rivers, that it is common, in the Elbe to the north, and the Danube on the south, and in the rivers still further west; and it is one of the fishes brought to the market at Constantinople. It occurs in the Scandinavian peninsula but rarely. In the rivers that fall into the Caspian it is very common, but it is a stranger to all the Siberian rivers which flow towards the Arctic Ocean. It is undoubtedly the Glanis of Aristotle.

The Synodonts of all the Siluroids that possess an adipose fin are the most remarkable for the armature of the head and nape, as they are also for their peculiar dentition. They are either destitute of parietals, or these bones at an early period of the life of the fish coalesce with the suprascapular. The suprascapula extend to the sides of the suprascapital, but this latter bone goes still further backwards to join the second interneural plate; embracing, in conjunction with it, the plate of the first interneural, as we have mentioned above. The process of the suprascapula which rests on the basioccipital descends lower, and expands into a thin plate, to which the anterior lobe of the air-bladder is attached. The ossicles of Weber are present in their usual form; but the first parapophysis of the compound or coalescent anterior vertebral centra reaches forward between the suprascapula and exoccipital, and then sends a thin plate downwards into the air-bladder, in which it forms a diaphragm. The coracoids and ulnaro-bones, united below by suture, expand upwards in form of a vertical plate, which constitutes a bony diaphragm, dividing the branchial from the abdominal cavity, leaving a single opening for the passage of the oesophagus. Some species of Synodontis have been supposed to be the Nile fishes mentioned by Strabo, under the name of Ἀσπερος (Asperos), which, according to Aristotle, are the only marine fish that are not deterred by dread of the crocodile from ascending the Nile. This Saurian does not dare to attack it on account of its strong spines. The Mugilis also ascend the river, but it is under the protection of the Synodonts. The species of which Strabo speaks has not yet been clearly made out, and may possibly be a Siluroid of a different group.

The Doros of South America have excited attention by their habit of travelling during the dry season from a piece of water about to dry up, in quest of a pond of greater capacity. These journeys are occasionally of such a length, that the fish spends whole nights on the way; and the bands of scaly travellers are sometimes so large, that the Indians who happen to meet them fill many baskets of the prey thus placed in their hands. The Indians suppose that the fish carry a supply of water with them, but they have no special organs like the Anabas, and can only do so by closing the gill-openings, or by retaining a little water between the plates of their body, as Mr Hancock supposes. This gentleman adds, that both the Doros and Callichtys make regular nests, in which they cover up their eggs with care, and defend them, male and female uniting in this parental duty until the eggs are hatched. The nest is constructed at the beginning of the rainy season of leaves, and is sometimes placed in a hole scooped out in the beach. The Callichtys differ in many parts of their skeleton from other Siluroids, and their cranium does not owe its breadth to the expansion of the supra-temporal, but to the development of the three frontal, and the coalescence of a piece of the mastoid and suprascapula. These fish, like the Doros, travel in search of water, and sometimes bury themselves in the mud of wet meadows, where they are often captured by the natives, who dig them The Callichthys are monogamous, both male and female remaining by the side of the nest, and watching it carefully. A specimen of the nest, spawn, and fish, exists in the College of Surgeons of London.

Arges, Brontes, and Astroblepus, are three forms of Siluroids of exceeding interest. They are some of the small fishes which issue from the bowels of the active volcanoes of South America, and are carried into the plains beneath by the torrents of muddy water, which these mountains vomit forth. They issue from Cotopaxi, Tungurahua, Sangay, Imbaburu, and Cargueirazo, a phenomenon first properly communicated to the scientific world by the illustrious Humboldt. They are expelled from craters or from lateral openings, always 16,000 or 17,000 feet above the sea, and the plains themselves into which these clayey streams descend, lie at least at half that height. Humboldt ascertained, by consulting the records of the neighbouring towns, that in 1691 Imbaburu threw out myriads of these fish in the neighbourhood of the city of Ibarra, and has continued to do so down to a late period. Cotopaxi also covered the estate of the Marchese di Salvatégre with so large a quantity of these subterranean Siluroids, that the odour of their decaying bodies spread far and wide, so much so indeed, that the pestilential fevers which then prevailed were attributed to these putrid exhalations. In the eruption of 1698, when the peak of Cargueirazo fell in, vast quantities of these fish were brought down by the muddy and smoking streams which the mountain poured forth. M. Humboldt has proposed many questions bearing on these facts, without offering a solution. What streams of water, or what lakes exist in the cavernous recesses of these mountains? How does it happen that water submitted to so high a temperature retains air enough to support the life of such multitudes of fishes? How do animals with flesh so soft escape being cooked as they pass far, and for a long time, through the smoke which envelopes the streams of mud that issue during the eruption? These fish are called in the country preñadillas, a name not confined to a single species. The one that Humboldt specially described is the Argus cyclopus, originally named by him Pinotodus cyclopus.

In Claras the nape is not armed, and the development of the bones of the head is lateral; the suborbitars, which, in the rest of the family, are mere slender tubes, in this genus give extension to the helmet, and the supratemporals which, in most fishes are very small, and in the greater number of Siluroids are imperceptible, here become enormously large, and coalesce on the sides of the cranium, with the prefrontal, frontal, postfrontal, and mastoid. An apparatus for holding water in the vicinity of the branchiae exists in this genus, and its near allies analogous to that of the Anabasidae. The Claras anguillaris of Hasselquist has been by some writers on Egypt considered to be the Alabes of Strabo, cited by Archestratus, as one of the sacred fishes of the Nile. It is now known on the banks of that river by the name of Harmouth, or, as Sir Gardner Wilkinson writes the word, Karmoot. It was either worshipped, the latter author says, in the Thebaid, or was connected with one of the genii of the Egyptian Pantheon, who appears under a human form, with the head of this fish in the sculptures of the Diospolite tombs. In Lower Egypt the Karmoot was caught for the table; but there is no evidence of its having been eaten in the Thebaid, which may be an argument in favour of its sacred character.

Plotosus is a genus of the Siluroid family which frequents the seas of southern Asia and the eastern coasts of Africa, and from thence southwards to Australia, where there are several species. One of these, PL microcops, is represented by the annexed woodcut, and the lips by figure 30.

Aspredo differs greatly from the rest of the Siluroids, and from other osseous fishes, in the rudimentary and immoveable condition of its gill-flaps, the three pieces that generally perform the office of a valve to the gill-openings being mere vestiges confluent with the preoperculum in such a way, that the opening and closing of the aperture does not depend on the tympanico-opercular apparatus. The mouth likewise is peculiar, the premaxillaries being articulated longitudinally, so that the orifice is a slit in the axis of the fish, with teeth in its posterior part only. Some curious sucker-like appendages are formed on the females at certain times by the expansion of pores and development of filaments on their edges. These are not found in the males. Bloch named a species Cotylephorus which had these organs, and McClelland has characterized a genus chiefly by their existence. Their presence, however, appears to be temporal, and to extend to the females of all the species.

Malapterurus electricus, Lacép. The electric powers of this fish were noticed by Adanson in 1756, but in Purchas' Pilgrims, there is a much earlier account of it extracted from the narrative of Baretus and Oviedo, dated 1554. It is there said, that there exists in the Nile a fish (called by Purchas a torpedo), which, if held in the hands, causes on the slightest movement a severe pain in all the arteries, nerves, and joints of the body. In the same work Richard Johnson is reported to have perceived in the River Gambia a fish like an English Bream, but thicker, which, on one of the sailors taking hold of, he instantly cried out that he had lost the use of his hands and arms. Another sailor, on touching the fish with his foot, felt his legs benumbed. This was in 1620. As the Malapterurus abounds in the Nile and in Senegal, and the torpedo has no resemblance to a Bream, the former was doubtless the fish to which Purchas alluded, notwithstanding his use of the name Torpedo. Rudolphi has given a detailed description, with figures of the electric organs of this fish. In the great work on Egypt by Geoffroy (Pl. XII., 2), there is the figure of a Malapterurus opened to show the viscera, but by a singular inaccuracy the fish is represented as scaly; now there are no scales whatever on this fish, and no fish known to possess electric powers has either scales or spines. The Torpedo, the Gymnotus, and the Malapterurus, have all naked skins. The Tetradon electricus is also destitute of spines on the skin, though all its congeners have skins as bristly as those of a hedgehog.

M. Valenciennes, examining the electric organs of the Malapterurus with a full knowledge of what had been previously observed by Geoffroy and Rudolphi, describes it as being composed of a thick layer of spongy cellular tissue, lying immediately under the skin, and framed of thin interlacing leaflets, filled with a gelatinous fluid, and lined on its internal face by a silvery aponeurosis to which it adheres strongly. This aponeurosis extends from the forehead and the gill-openings to the posterior end of the anal, and is divided into lateral halves by a membranous raphe that appears on the dorsal and ventral aspects. Under this aponeurosis run the great vascular and nervous trunks, whose branches pass through it, to be expended on the cellular tissue. Then beneath this aponeurosis there is a peculiar membrane which forms the subject of Rudolphi's Memoir. It consists of at least six layers, readily separable the one from the other, as well as from the subjacent muscles, to which it is attached merely by a loose and scanty cellular tissue. These aponeurotic layers extend to the caudal. They are thin, dense, and can be stretched under the finger; their external surfaces become flocculent when they imbibe water. These flocculi resemble moist cotton, and when examined with a high microscopic power, present a felt-like interlacement of extremely minute fibrils. The tunics receive from their interior sides filaments of the same nerve (par vagum, Rudolph) which runs under the aponeurosis. There are other filaments also of extreme tenacity, which penetrate the six layers to expend themselves on its interior surface; these spring from the intercostals. In thus deriving the nervous energy of its electric organs from the "vagus" and from the "rami ventrales" of the spinal nerves, as well as in possessing the cellular apparatus of the Torpedo and the laminated membranous one of Gymnotus, the Malapterurus combines the characters of these two genera in its peculiar organ.

In the Edinburgh Philosophical Journal for 1856, Mr Murray gives a good figure of a species of this genus from the Bight of Benin. The Arabs, fully appreciating the nature of the numbing powers of the Malapterurus, name it Rand or Raasch (thunder). The fish gives its discharge when touched on the head, but is powerless when held by the tail, and in fact the electric organ does not reach the caudal fin. In giving a shock it moves the tail however, as it must do when the muscles of the body are acting. A fish of only seven inches in length can give a vigorous discharge. The fish is eaten, and it is one of the most esteemed Siluroids as an article of diet.

M. Valenciennes considers Trichomycterus and Eremophilus as forming a link between the Siluroids and the Cyprinoids, through Colias; indeed, he was long in doubt as to which family they actually belonged, and he has been led to assign them a place among the Siluroids chiefly by the absence of subopercula. The want of an adipose fin weighed less with him, as this member is wanting also in some Siluroids; neither does he consider the absence of ventrals of sufficient importance to exclude a genus from a family group. Trichomycterus were found by Mr Pentland in the rivulets which fall into that vast alpine sheet of water, Lake Titicaca, which is frequented by the Cyprinoid Orestias, also an apodal, and in the affluents of the Apurimac, one of the sources of the Amazon. He discovered them also in Rio de Guatamali, Rio de Pontezulmo, and in Lake Compuila, on the Andes, to the west of Cuzco, and at an elevation of 14,000 feet. Eremophilus inhabits the waters of the Valley of Bogota, 8500 feet above the sea level.

**Family XVIII.—Siluridae, Agass.**

Skin naked, or covered with bony shields, without scales. Premaxillaries forming the border of the upper jaw, the maxillaries being reduced to mere vestiges, or elongated into barbels; all have barbels; suboperculum wanting. Epibranchial wanting, or reduced to a mere process of the ceratoid. The postfrontal or temporal apparatus has two ossicles less than in most osseous fishes; the pseudobranchiae are wanting. The swim-bladder is present in the majority, and is connected by a chain of ossicles with the acoustic organ; no pancreatic cases; stomach caecal. In most the pectoral ray is very strong and serrated; most have an adipose fin upon the back. Branchiostegals nine to eighteen.

**Analytical Table of the Siluridae (Dum.)**

| Dorsal, single (Silurides, Dum.) | | |----------------------------------|--| | Dorsal, containing bony rays. | | | Dorsal extending along the whole back, Claras. | 33. | | Dorsal short, with | | | Its spinous ray close to the skull. | Trachelyopterus 24. | | Its spinous ray on the back. | | | Caudal forked. | Schilbe 2. | | Caudal rounded. | Brontes 31. |

**Genus I. Silurus, Linn.**

Dorsal short on the fore part of the back, without sensible spines; no adipose fin; a long anal. Raduliform or card-like teeth on the jaws, and a band of vomerine ones behind the premaxillaries. Some have four barbels, and some only two. Sixteen species.

**Genus II. Schilbe.**

A strong, denticulated dorsal spine, elevated nape, broad depressed head, greatly compressed body, and very distinct teeth. Barbels eight. Branchiostegals eight to ten.

**Genus III. Cetopsis, Agass.**

Eyes almost imperceptible, being nearly covered by skin. Six barbels. One dorsal composed of soft rays. Convex, obtuse, truncated head; moderate mouth; single row of teeth on the mandible and front of the vomer; a band sometimes on the premaxillaries. Gill-opening a small hole; branchiostegals nine.

**Genus IV. Bagrus, Cav. and Valenci. (Myrus, Artedi.)**

A rayed dorsal with spine, and an adipose one; a pectoral spine. A band of villiform or card-like teeth on the premaxillaries, behind which, on the roof of the mouth, there is a second arch; villiform band, or a single row of teeth, not separated in the middle. They are divided into groups according to the number of their barbels, and subdivided by the forms of the head, the lengths of the adipose or anal, and variations in their dentition. Sixty-one species are described in the Histoire des Poissons. In Bagrus niloticus the air-bladder is divided by a septum, in which there is no opening; and in other species, the lateral compartments are subdivided by transverse septa.

**Genus V. Pheactochthales, Agass. (Sisorus, Spix.)**

Incomplete osseous rays, encased in the upper border of the adipose fin. A flat head, with a deeply sculptured bony casque; and an expanded transversely oval shield before the dorsal, free, and altogether detached from the bones of the skull. Nine branchiostegals; six barbels round the mouth.

**Genus VI. Platystoma, Agass. (Sorubim, Spix.)**

Snout depressed. Branchiostegals numerous. A transverse band of teeth, but more completely divided by the smooth median line of the vomer into two plates on each side, than in the Bagrus. Thirteen species.

**Genus VII. Galeichthys, Valenci.**

Head rounded, skinny, and without a conspicuous caudal. First dorsal ray elongated into a flat extensible filament. The palatine teeth a narrow band divided by smooth lines into four patches. Branchiostegals six; four or six barbels. Five species.

**Genus VIII. Pangasius**, Valenciennes. Four short barbels; no prolongations of the fin rays. Ten branchiostegals. Air-bladder divided into four parts by three contractions. One species.

**Genus IX. Siluridae**, Valenciennes. A small smooth head, like that of Schilbe. Very small adipose fin; long anal. Only two small (maxillary) barbels; teeth of the jaws hooked, and longer than in other Siluridae; a transverse band in front of the roof of the mouth, as in Bagrus. Twelve branchiostegals. Two species.

**Genus X. Schilbe**, Malm and Troschel. A cross band of palatine teeth, and behind them two clusters.

**Genus XII. Eutropius**, Malm and Troschel. Palatine teeth forming two separate patches, and sometimes farther back a single tuft only.

**Genus XIII. Arius**, Valenciennes. Teeth on the roof of the mouth disposed in two widely-separated plates, supported for the most part by the palatines only, but in some species encroaching on the angle of the lower jaw. Branchiostegals five to eight, rarely ten to twelve. The teeth may be villiform or pavement-like, the passage to the pavement-like teeth being gradual; some species have the ordinary nuchal armour of a triangular (interparietal, Cuv.) supraoccipital plate, with the apex truncated, and a small crescentic interspinal plate; others have a very large separate supraneckial disk, and the barbels vary in number. On combinations of these diversities of structure several groups are established in the *Historie des Poissons*, in which fifty-one species are described. Air-bladder in some divided lengthwise into two separate portions.

**Genus XIV. Osteogaster**, Bleeker. A mackerel and an adipose dorsal fin. Conical teeth acute, conical, crowded teeth on the premaxillaries and mandibles; in many rows; palatine teeth in two oblong arched plates in the fore part; the medial line of the roof of the mouth smooth; eyes far back. Two premaxillary barbels, bony and rigid. Branchiostegals five. Head cuirassed; gill-openings extremely narrow. Indian Archipelago.

**Genus XV. Batrachocarpus**, Bleeker. Dorsal fins two, the hinder one adipose. Thick, cylindrical, premaxillary and mandibular teeth in many rows; vomer and mesial line of the roof of the mouth smooth; a few crowded cylindrical teeth on the anterior angles of the palatine bones; eyes above; head cuirassed; no barbels. Five branchiostegals. Indian Archipelago.

**Genus XVI. Paraloricari**, Lacépéde. Roof of the mouth smooth, edentate; barbels six or eight. Some species want the caudal; others possess it; it is sometimes continuous with the buckler of the first oesophageal ray of the dorsal; sometimes distinct and not continuous. Forty-three species are described in the *Historie des Poissons*.

The following two genera have been published since the date of that work:

**Genus XVII. Rita**, Bleeker. Dorsals two, the posterior one adipose. Conical teeth in the upper jaw plurilateral; mandibular teeth conical in the anterior rows, granular in the posterior ones. Vomer-palatine teeth granular, disposed in two oblong patches in the fore part of the palate. Branchiostegals eight or ten; barbels six. Smooth roof of the mouth; premaxillaries, and mandible. Ventrais eight-rayed. (*Arctosoma*, Cuvier and Valenciennes.)

**Genus XVIII. Bagarius**, Bleeker. Dorsals two, the posterior one adipose. Barbels eight, on the jaws bony, rigid; upper jaw teeth plurilateral, acute, placed in a curved quadrilateral band; mandibular teeth biseiral, with an interior series of canines at the symphysis only; no teeth on the vomer, palatines, or entopterygoids. Branchiostegals twelve. Rays of the ventrais six. No air-bladder.

**Genus XIX. Ecanemus**, Malm and Troschel. Narrow gill-openings. Body laterally compressed. Cranial covered with skin. Cartilage teeth in one row on the upper and under jaw; none on the vomer or palatines. First ray of the dorsal and pectoral fins spinous; dorsal fin wholly anterior and small; a very small adipose fin; rays of the ventrais much more numerous than in other Siluridae. Eyes covered with skin. Barbels six. One species *E. colombiensis*.

**Genus XX. Ketengus**, Bleeker. Dorsal fins two, posterior one adipose. Cuneiform uniserial teeth on the premaxillaries and mandible; vomer and palatines smooth. Head cuirassed; eyes superior. Five branchiostegals; four fleshy barbels. Strait of Malacca.

**Genus XXI. Calophysus**, Malm and Troschel. No palatine teeth; a row of stronger teeth on the upper jaw and mandible, behind which, on the one or the other, a row of smaller teeth. The end of the first dorsal and pectoral ray simply jointed, not denticulated; fin—M. a long adipose fin. Six barbels; narrow gill-opening; seven lacopteri, branchiostegals. A very small swim-bladder, which is bordered behind with an elegant fringe of caudal processes. Two species.

**Genus XXII. Eremistes**, Muller and Troschel. Narrow gill-openings. Head big, broad, pointed anteriorly, rough. Besides the occipital process there is always another like it. The scapular giraffe has a long bony process above it, covered with skin, behind it; mouth small. Card-like teeth in the upper and under jaw; none on the palatines. A movable spine forming the first ray of the dorsal and pectoral fin; an adipose fin; anal small.

**Genus XXIII. Acuchilipinnis**, Valenciennes. Siluroid with an adipose fin. Head small; teeth almost imperceptible. Branchiostegals five; no teeth on the roof of the mouth. Dorsal very far forward, or on the nape. Caecae united by sutures with the dilated bucklers of the first and second interspinals covering the nape to the dorsal, as in Doros and Synodontis. Seven species.

**Genus XXIV. Trachelyopterus**, Valenciennes. No adipose fin; yet allied to Schilbe and Pimelodus. No barbels. Villiform teeth on the jaws, none on the roof of the mouth. A solid, oesophageal unitus in a median line, extending from the dorsal, down to the umbilicus of the supraneckial plate, and the completely obsolete chevron. Pectorals attached under the throat. One species.

**Genus XXV. Hypophthalmus**, Valenciennes. An adipose fin. No teeth; eyes near the ventral aspect. Fourteen branchiostegals. Dorsal small, well back, with a bony ray; a strong ray in the pectoral also; ventrais small; anal long. Six barbels. Three species.

**Genus XXVI. Ageneiosus**, Lacépéde. Maxillary barbels both, and very short; in one species denticulated and resembling horns. Eyes depressed as in Hypophthalmus. Branchiostegals eleven. Three species.

**Genus XXVII. Synodontis**, Geoffroy St Hilaire. Remarkable among the Silurides having an adipose fin for the armoring of the head, which shows much affinity with that of *Acuchilipinnis* and Doros. Supraneckial plate large, united by a long transverse suture with the greatly dilated interneural buckler, which is further prolonged along the base of the dorsal by its junction with three interneural plates; very wide strong pointed cornicoids attached to the supraneckials which form the lateral angles of the helmet. Enormous strongly-toothed pectoral spines; a high pointed and trenchant dorsal spine. Scoop short, terminating in the nasal which supports very short prenasal barbels covered with finely villiform teeth. Mandible composed of two short slender limbs, and carrying in each a bundle of teeth that, individually, are very thin lancets, each supported on a stalk as fine as a hair, and terminated by a small recurved and gold-coloured hook. This dentition resembles that of Sauridus.

**Genus XXVIII. Doras**, Lacépéde. *Pimelodellus* with the lateral line cuirassed by keeled bony plates, each ending in a spine. Head armed as in *Auchenipterus*, and the cornicoids similarly formed. The very thick dorsal and pectoral spines are strongly hooked. In others, the scoot is depressed, and the mouth at its extremity is furnished with two broad villiform bands of teeth on either jaw. In others, the mouth is a round tube under the cornual mouth, and having small groups of mandibular teeth only. Ten species.

**Genus XXIX. Calligobius**, Linnaeus. *Pimelodellus* cuirassed on the lateral line like the *Doras*, and with an adipose fin; but the lateral shields are narrow, embrace the whole height of the fish, and form two rows, somewhat tilted and crossing in the middle. Head covered with a helmet; mouth small, almost toothless; two barbels at each corner of the mouth. Three branchiostegals. Dorsal and pectoral spines often feeble. No air-bladder; intestine frequently doubled back; stomach globular and small. Ten species.

**Genus XXX. Anguilla**, Valenciennes. Teeth bifid and slightly curved at the points, ranging in rows on the jaws and producing a sort of narrow whale-like pharynoid, nor any other fish, is known to possess. Roof of the mouth smooth and edentate; two maxillary barbels, and papillae at the nostrils. First dorsal small, with a weak ray in front; adipose fin long; ventrais well forward. Four branchiostegals. Two species.

**Genus XXXI. Brontes**, Valenciennes. An Anguilla without the adipose fin. No caecae. Eyes, two minute points on the top of the head. Branchiostegals four. One species.

**Genus XXXII. Astroblepus**, Humboldt. An opsid resembling otherwise, externally, *Brontes*, having a depressed head; eyes above. A single dorsal; no adipose fin. First rays ending in filaments. Four branchiostegals. One species.

**Genus XXXIII. Clarias**, Grumov. Helmet extending to the temples and cheeks; the supraneckial point more or less rounded, in some semicircular. Nape exposed; no preorbital buckler. Teeth on the jaws and arc of the vomer. Head depressed, obtuse. Body long; caudal truncated. Anal long and low; dorsal without

Two distinct species of this order, family, and genus are known; one an inhabitant of the River Amazon, whose structure has not been so fully investigated, and the L. annectans from the Gambia, which has been minutely dissected by several of the first comparative anatomists of the day, and been the subject of much scientific controversy as to its station in the animal scale, whether it ought to be ranked with the reptiles or fishes. Professor Owen from the first advocated its ichthyic constitution, and Bischoff maintained its reptilian character; but Owen's reasoning appears to us to be perfectly conclusive. In a preceding page we have briefly noticed the habits of the Siluroid Hassars (Calliechthys) in taking shelter in the muddy bottoms of marshes, and when these dry up, digging burrows for themselves to a considerable depth. They can live long out of the water and make overland journeys in quest of it; but if we understand the accounts given by travellers, they can, in the event of being cut off from water, pass the dry season in an inactive state in their burrows, from whence they are dug out by the natives, who use them for food. Some moisture will, doubtless, always remain about them in their subterranean abodes, but still their condition until the rains commence must be analogous to the hibernation of animals in higher latitudes; they enjoy but a torpid kind of existence, and use no exhausting muscular exertion until the refreshing water flowing in recalls them to an active employment of all the organs they possess as fishes. The conditions of existence of the Lepidosiren annectans must, as far as regards external circumstances, be similar during the dry season, though that internal organization which enables it to pass much of its life out of water is of a very different kind. This fish inhabits the Gambia, which in the rainy season floods extensive tracts of country. On the waters retreating after the rains have ceased to fall, the Lepidosirens that are left behind burrow into the mud, which a tropical sun soon converts into a hard cake. An aperture is left, however, that admits air, and they remain in their chamber, torpid and clothed in a thick secretion of mucus, until the water again overflowing the muddy lands, releases them to the enjoyment of the swimming powers, which they employ in search of food to allay the cravings of a keen appetite. They have been brought to this country imbedded in clay round the roots of plants imported from the Gambia, and their presence only became known after the plants were placed in the stove and well watered. It is by a modification of the air-bladder rendering it analogous in function to the lungs of an Amphibian, and also by a peculiarity in the gills, that the Lepidosiren is adapted to the alternate conditions of an active tadpole-like fish, and an air-breathing dweller on the dry land. As a general rule, all fishes more highly organized than the Dermopterii have, in their embryonic stage, five branchial arches and five branchial arteries. In osseous fishes the anterior or hyoid arterial arch develops either a gill of a single layer only, or a rudimentary gill consisting of a network of vessels, or both, or neither. The normal number of branchiae, with double pectinated lamellae in osseous fishes is four; most of the Labroidei, the genera Cottus, Scorpana, Sebastes, Apistes, Zeus, Cheironemus, Gobiesox, Lepidogaster, and Polypterus have three bilamellated or biserial gills and one uniserial one; Lophius, Batrachus, and the Gymnodonts have three biserial gills; and Malthea and Lepidosiren have two biserial gills and one uniserial gill. Two of the arterial arches, which in other fishes supply a pair of branchiae, remain undivided in Lepidosiren, and in their primitive condition of vascular hoops, which end directly (in a manner analogous to the ductus arteriosus of young mammals) in arterial trunks going to the air-bladders, and ramified over their cellular surface. While passing through the ultimate twigs of these arteries, the blood is sufficiently oxygenized to sustain life during the dry season, supplies of Classification—air being introduced into the air-bladders by a trachea whose respiratory orifice is kept open by a laryngeal cartilage. Mr Owen sums up in the following words the particulars of structure which induced him to consider the Lepidosiren to be a fish:—"It may be presumed," he says, "that its gelatinous chorda dorsalis, its vertebral inferior transverse processes (parapophyses), the normal attachment of the scapula to the occiput, the branchio-vertebral covering of the permanent gills, the opercular bones, the absence of a pancreas, the presence of a spiral intestinal valve, the relative position of the anus, the extra-oral nasal sacs, the scaly integuments, the mucous tubes and pores on the head, the 'lateral line,' and, in short, the totality of the organization of the Lepidosiren, will be deemed fully to prove its true ichthyic nature." This passage gives, in fewer words than we could have employed, the reasons for introducing the order of Sirenoidea into our table of the class of fishes. In a discussion which took place at a meeting of the British Association soon after the publication of Mr Owen's paper on the Lepidosiren in the Transactions of the Linnean Society, the debate turned much on the presence of a posterior nasal orifice in the cavity of the mouth, but the Lepidosiren has an elongated nasal sac, with the biserial pituitary folds usual in fishes, and two apertures, neither of which communicate with the mouth; and Owen attributes to the position of the nasal sac in the under part of the thick lip the mistake of those naturalists who affirmed that the posterior opening was within the mouth. We have in a preceding page mentioned an instance in the Synbranchidae of the posterior nasal opening being as much on the interior side of the lip as in Lepidosiren. Though the homology of the air-bladder of Lepidosiren with the lungs of Batrachia is undeniable, and by a legitimate train of reasoning, the air-bladders of other fishes are also proved to be homologous with the lungs of the higher classes of vertebrals, there is no ground, Mr Owen remarks, for asserting that the air-bladders of fishes in general perform the functions of a lung. Such oxygenation of the blood as a fish requires is effected through the agency of gills, though the relationship of these organs to the tracheae and lungs of the higher vertebrals is one of analogy merely. The branchiae of fishes are, however, homologous with the persistent or deciduous branchiae of Batrachia, and with similar organs in embryos.

In Lepidosiren the optic nerves do not cross each other, agreeing in this respect with the same parts in Polypterus, the Surgeons, and the Plagiostomes. In ordinary osseous fishes the nerves cross, but without an intermixture of nervous fibrils.

ORDER IX.—PROTOPTERI, Owen.

Sirenoidea, Mill. Endo-skeleton partly osseous, partly cartilaginous; exo-skeleton as cycloid scales. Pectorals and ventrales as flexible filaments. Gills filamentary, free. No pancreas; swim-bladder as a double lung with an air-duct; intestine with a spiral valve.

FAMILY I.—SIRENIDÆ.

Sirenoidea, Mill. General form resembling that of an Ophidion, with a more tadpole-like tail. Pectorals and abdominal ventrales single, slender, tapering barbels, supported internally by a soft cartilaginous ray. Gills operculated.

GENUS I. LEPIOSIREN. (Protopterus, Owen.) Two species, L. annectans, Gambia; L. paradax, Amazon.

ORDER X.—HOLOCEPHALLI.

Endo-skeleton cartilaginous; exo-skeleton as placoid granules. Most of the fishes with a strong spine for the first ray. Ventrales abdominal. Gills laminated, attached by their margins; a single external gill-aperture. No swim-bladder; intestine with spiral valve. Copula gonadum.

FAMILY I.—CHIMÉRIDÆ.

Chiméridæ. Internally five gill-apertures which communicate

Or Cartilaginous fishes, are called by Cuvier the second series of the class, and he considers them to be neither inferior nor superior to the Osseous fishes forming the bulk of the first series, for many of the genera come near the Reptiles in the structure of the acoustic organ, and in the genital apparatus, whilst others have so simple an organization, and such imperfect skeletons, that they can scarcely be classed with confidence as vertebrals. He therefore looks upon them as a parallel series to the ordinary fishes analogous to the relationship that exists between the Marsupials and the ordinary Mammals. It is right to observe, however, that the very low organization of some Chondropterygians here alluded to has reference to the Cyclostomata placed at the commencement of our table, and their exclusion, leaving only the Sturgeons, Sharks, and Rays, presents the organization of the Chondropterygians, as of a higher and more equable general character, by which strength is added to Cuvier's reasoning. Yet there are many embryonic characters persistent in the Chondropterygians of which the cartilaginous and confluent vertebrae, as departing most from the indurated endo-skeleton of the highest and newest vertebrals, is the most striking. We have already observed that many of the characters assumed by the embryos of existing fishes in the progress of their development were the permanent condition of the fossil fishes found in the oldest fish-bearing strata, and (as will be more fully explained in the article on Fossil Ichthyology, which follows) the researches of Agassiz have shown that as we ascend from the older to the newer deposits there is a progressive predominance of the endo-skeleton over the exo-skeleton, so that the Placoids of that author, or the Plagiostomous Chondropterygians are few in number in the present day compared to the osseous fishes, and the Ganoids with their heavy armour are much more sparingly represented still. During the chalk epoch both Ganoids and Placoids were in much greater numbers, and they are the only members of the class of fishes which have been found in the deposits below the chalk. Mr Owen has some most instructive sentences bearing on this point in his remarks on the genesis of fins. The development of fins, he observes, is at first restricted to the region of the head, as in most of the ancient Cephalaspid fishes—Pterichthys and Pampylactus for instance—in which the cephalic fins project from the opercular region before the nuchal plates, and there is no trace of true pectoral, ventral, or of vertical fins. In existing fishes the only thing analogous to these cephalic fins is the development of the sides of the skull in the Rays by the fore corners of the pectorals, or in Cephaloptera and Ceratoptera, by what Müller calls "cephalic fins," but which he considers to be merely detachments of the pectorals, though connected with them only by integument, and not by a continuous succession of fin-rays. In others of the ancient fossil genera there are two closely approximated dorsals and two anal fins, and both are situated near the end of the tail, which runs into the upper lobe of an unsymmetrical caudal fin. Now, in the embryos of existing osseous fishes these vertical fins are developed from a single continuous fold of integument, which is extended round the point of the tail from the dorsal to the ventral surface; a condition which may be observed in the tadpoles of Batrachians, and which is persistent in the Eel and Lepidosternum. The growth of this fold is progressive at certain parts, and checked at others; and in places where development is active, the supporting dermal rays make their appearance, and the transformation into dorsal, caudal, and anal fins is thus effected. At first the caudal fin is unequally lobed, and the terminal vertebra extend into the upper and longer lobe; the dorsals and anal are also at first closely approximated to each other and to the caudal fin. M. Agassiz has shown that all these embryonic characters were retained in many of the extinct fishes of the old red sandstone; and the caudal fin did not pass the heterocercal stage in any fish until after the Jurassic or oolitic epoch. The heterocercal caudals are the predominating and almost exclusive form in the existing Sturgeons, Sharks, and Rays, and in most of these one, or both dorsals when there are two, are situated upon the tail, and not rarely near its extremity. The cutaneous seams without rays and other embryonic conditions are also common, as may be learnt by consulting the generic characters in the table.

Cuvier observes that the parts of the skeleton of the Selachians (under which epithet he comprehends the Sharks and Rays) do not assume the fibrous structure of bone; their interior remaining always cartilaginous, and the induration of their exterior proceeding from the deposition of the earthy matter in a granular state, whence their characteristic dotted surface. It is on this account he infers that their calcarea are not divided by sutures, but are composed of a single shell, modelled, however, in other respects after the general plan of an ordinary fish-skull; so that we can distinguish the same regions, similar depressions and eminences, and the same holes. He gives an analysis of the vertebral cartilage of Selache maximus, which shows that water alone forms ninety per cent. of the mass, while nearly seven are oil and other animal matters, and little more than three of earthly salts.

Owen selects Squatina (the Monk-fish), an intermediate form between the Sharks and Rays, as a good typical example of the characters of the skull of a Plagiostome. The cranial end of the "chorda dorsalis" and its capsule are converted into firm granular cartilage, which, extending forwards from a prominent median basal-ridge, and also expanding laterally, constitutes the oblong flattened plate or base of the cranium. Two convex condyles are formed on the posterior margin of this "occipito-sphenoidal" plate for articulation with the end of the spine. Two notches on the side of the basal cartilage define a prominence representing the sphenoidal arch, which sends off a rudimental pterygoid; and further forward there is an expansion and groove forming the point of suspension of the palato-maxillary arch. Then the cartilage suddenly contracts, and is continued forwards to form the vomerine anterior base of the cranial cavity. The walls of this cavity are as firm and granular as the base, except at the antero-superior end which is closed by membrane only. The foramen magnum posteriorly gives passage to the spinal chord, and there are perforations for the exit of the cerebral nerves.

The cranial cavity is of larger size than the brain, and communicates only by nervous and vascular foramina with the acoustic labyrinth, which is buried in the side of the cartilage. In the Chimere, this insulation of the ear-capsules, denoting a high grade of development, is much less complete. The parts of the cranial cartilage, corresponding to the separate bones of the skull of an osseous fish, may be recognised by the foramina through which the several pairs of nerves pass; but the exterior of the skull is variously and singularly modified in the different Plagiostomous genera.

In the appended arches of the cranium there is a similar confluence of cartilage. A single strong suspensory pedicle articulated to the lateral posterior or mastoid process gives attachment to the hyoid arch by a close joint, and to the mandibular arches by two ligaments. The maxillary arch is suspended by a ligament passing from its ascending palatal process to a notch between the vomerine and the anterior supracranial cartilage. From this point the upper jaw is continued in one direction forwards and inwards, completing the arch by a ligamentous symphysis with its fellow; and in the opposite direction to coalesce with the outer side of the tympanic pedicel, and form the more immediate articulation for the lower jaw or mandibular arch. Each half of the mandible consists of a single cartilage, the two being united together at the symphyses by ligament. Two slender labial cartilages are developed on each side of the maxillary, and one on each side of the mandibular arch. (The parts described in this paragraph, with the teeth which they support, are the "Shark's jaws" usually brought home by seamen.)

Four or five short cartilaginous rays, in Squatina, diverge from the posterior margin of the tympanic pedicel, and support a membrane answering to the opercular flap of osseous fishes; these rays are the skeleton of the diverging appendage of the tympano-mandibular arch. The hyoid arch in the Squatina, as in most other Plagiostomes, consists of two strong lateral cerato-hyoïds, and a median flattened basi-hyoïd. Short cartilaginous rays extend from the back part of the cerato-hyoïd to support the membranous wall of the branchial sac; these are the homologues of the branchiostegal rays of osseous fishes.

The Centracion is not so far advanced in cranial development as the Squatina, and the cartilaginous basioccipital has a hollow conical articulation with the end of the spine; but the Skates and Rays have the skull movably articulated by two condyles and an intervening space, as in Squatina and Zygana. The skull of the Rays is flat and broad; the upper wall membranous to a greater or less extent, except in Narcine, where it is closed by cartilage. The anterior or vomerine part forms a long pyramidal rostrum, to which are articulated cartilages connecting its extremities with the radial or anterior angles of the pectoral fin, or largely expanded hand; in the space between the pectorals and skull the Torpedine carry their electric batteries. The tympanic pedicels are short and thick; the maxillary and mandibular arches long and wide, stretching across the under part of the head.

The capsules of the organs of sense are all cartilaginous; that of the ear is involved, as we have said above, in the lateral walls of the cranium; that of the eye is articulated by a cartilaginous pedicel with the orbit; and the olfactory sacs are covered by vaults of the nasal processes. The long lateral processes supporting the eye-balls of the "Hammer-headed Sharks" have already been alluded to. In Myliobates and Rhinoptera a cartilage is attached to the prolonged anterior angle of the pectoral fin, connecting it with the internasal cartilage, and supporting a number of branched and jointed cartilaginous rays. A like series of rays on the other side of the head meet these before the skull on the median line, and form what Miller terms, as we have said in a preceding page, "cranial fins;" but Owen considers them to be merely dismemberments of the pectoral fins, and thinks that the real cranial fins are the opercular and branchiostegal appendages of the tympanic and hyoidean arches.

In tracing the progressive rise of organization of the spinal column in the Cartilaginous fishes, Owen commences with the Myxinoid fishes, whose spine is a gelatinous chorda with fibrous investments. The separation of the upper layers of the fibro-membranous sheath forms a neural canal, and a haemal canal is produced below in like manner. In the Sturgeon there is a continuous central gelatinous chorda, but the inner layer of the fibrous investment assumes the texture of tough hyaline cartilage, while distinct, firm, and opaque cartilages are developed in the outer layer. Above the coalesced centra these cartilages have a similar arrangement to the homologous parts of osseous fishes; a neural canal is formed by two cartilaginous neurophyses, each in the young fish formed of two superimposed pieces, and the arch is crowned by a single short neural spine. There is a short thick parapophysis on each side, with their bases expanding below to form a haemal canal in the tail, by their union beneath the centrum. They include a small interhaemal cartilage on each side, and towards the end of the tail, haemal cartilaginous spines are developed. Short pleural physes or ribs are articulated to the ends of the parapophyses. A beautiful progression, in the development of the spinal column and of the proper vertebral structure, is traced out by Müller in his Anatomie der Myxinoiden, and referred to by Owen, from whom we quote. In the Basking Shark (Selachus) the vertebral centra are formed of hollow cones, meeting at their apices in the interior, and having their cups filled with the remains of the gelatinous chorda. This semi-fluid, slightly compressible, and very elastic, gives flexibility to the spine, while it sustains the shocks of violent inflexions. Strength and lightness are imparted to the centra by concentric plates of bone, crossed by others radiating like the spokes of a wheel from the apices of the cones. The highest stage of vertebral development occurs among Galei and other Nyctitantes or Sharks, which have a nictitating eyelid. In them the external surfaces of the centra, and their internal cones, are covered by a smooth osseous crust. A few Sharks only, as Carcharias, Heptanchus, and Atopias, have the ribs connected to the centrum at the base of the parapophyses; in most they are attached, as in the Sturgeon, to the ends of these processes.

The gills of the Plagiostomi do not present the pectinated arrangement of slender tapering processes in a double row, like the osseous fishes, but consist of folds of membrane on plane surfaces. A pseudobranchia coexists with a hyoid uniserial gill in most Plagiostomes, and in those which have spout-holes it is developed on the anterior wall of these outlets from the branchial cavity. The Plagiostomes have two or more transverse rows of semilunar valves in the bulbus arteriosus, or beginning of the arterial system; Galeus has two rows of three valves; Sphyrna, Mustelus, Acanthias, Alopias, Lamna, Rhinobates, Torpedo, and Accipenser have three rows of valves; Hexanchus, Heptanchus, Centrophorus, and Trygon have four rows of valves; Scymnus, Squatina, Myliobates, and Raia batis, or the common Blue Skate, have five rows. Cephaloptera has a very large bulbus arteriosus, and presents internally three longitudinal angular ridges, at the sides of which are small valves disposed in pairs, and in four or five rows; besides these there are three larger valves at the beginning, and three at the end of the bulb. The optic nerves of the Plagiostomes are connected by a commissure, but do not decussate as in the osseous fishes. And in this order the plexus of arteries, termed a vasoganglion, which lies between the layers of the choroid coat of the eye of most osseous fishes, does not exist. Müller found that generally when a fish possessed pseudobranchia, it had also the optic vasoganglia; but the Plagiostomes, Sturgeon, and Lepidosiren are exceptions, having the pseudobranchia, but wanting the vasoganglia. Mormyrus, Cobitis, Silurus, Pinneodus, Synodon, Muraena, and some other genera of the serpentiniform apodals, have neither the pseudobranchia nor the vasoganglia, but in most osseous fishes in which they have been sought for they have been found existing together.

The only other parts of structure of the Plagiostomes that Classification—Sharks.

We think it necessary to mention in the summary that our restricted limits compel us to resort to, are the organs of reproduction. In these fishes the secreting organs, or melts, are of compact oval or oblong form, and their efferent tubes communicate with the ureters, and terminate upon a rudimental organ in the cloaca. The claspers are present in the Chimaeridae as well as Plagiostomi, as appendages to the posterior edges of the anal fins, and have a fissure towards their ends, leading to a blind subcutaneous sac, which is well lubricated with mucus. In the Rays a glandular body aids its secretions to this mucus. The ovaria are smaller than those of osseous fishes, and the ova comparatively few in number. Some of the genera are viviparous, others ovo-viviparous, and others again merely oviparous.

SHARKS.

The Scyliorhinus or Dog-fishes, have the anal fin situated either before or beneath or behind the second dorsal, and are mostly spotted or coloured with lively tints. Their French names are Rousette or Rocher. The typical genus Scyllium has two representatives on the British coasts, Sc. canicula and Sc. catulus, both very common, and constantly taken by the fishers with bait at all the fishing stations round the coast, but more plentiful among the Orkney Islands than elsewhere. They are scarcely ever brought to market, but the fishermen do not disdain to eat them. Their flesh is remarkably white, but a little fibrous and dry. In the Orkneys they are skinned, split up, cleaned, and then spread out on the rocks to dry for home consumption. The skins are used for smoothing down cabinet work. There is no reason why the fins of these and other Sharks, so extensively used in China for making gelatine soups, should not be applied to the same purpose in this country, or dried for exportation to the East. Both the British species exist in the Mediterranean also. Six different species frequent the seas that wash the Cape of Good Hope, and there are at least two on the coasts of Japan and China. The only described species of Pristurus is a Mediterranean one, but individuals sometimes stray northwards to the British Channel; and one procured by Mr Couch, at Polperro in Cornwall, is figured by Mr Yarrell under the appellation of the "Black-mouthed Dog-fish." It is known at Madeira as the "Leitao de Mar," but is considered to be extremely rare. The handsome Hemiscyllium are Australian, and the Chiloscyllia belong to the Indian Archipelago and Polynesia. The curious bearded Crossorhynchos frequents the seas of Japan as well as those of Australia, where it was first discovered, having thus a range extending over many parallels of latitude. Ginglymostoma has a representative in the Indian Ocean and Red Sea, and another on the coast of Cayenne, and Stegostoma belongs wholly to the Eastern seas. Stegostoma fasciata is one of the most beautiful of the order, and has been observed of the length of fourteen or fifteen feet, with a large and blunt head, and tapering body. A few years ago one of them followed for several hours a Liverpool East Indiaman off Madagascar. It was elegantly transversely banded with alternate whitish and dark brown or blackish fasciae; and was further variegated by ocellated spots or rings on various parts of its body, which seemed to be about fourteen feet long. Its head appeared to be four and a half feet across, but the thickest part of its body did not seem more than two feet in diameter. It was accompanied by several Pilot-fish, which often swam before and returned towards it. Several attempts were made to catch it with large baits of fresh meat, but it never ventured to seize one of them. The lower jaw was distinctly visible whenever it opened its mouth, into which the accompanying fishes seemed to the spectators to enter and to leave at pleasure. The Scyliorhinus generally have the parts about the nose and mouth more divided into cutaneous lobes and barbels, evidently as organs of touch, and in harmony with their habits as Ground Sharks. For they require some guide to keep them from grazing against the bottom in their rapid pursuit of their prey.

Under the appellation of true Squali (Squalus properment dits), Cuvier comprehended all the remaining Sharks except Zygoptera and Squatinia, which he characterized as distinct genera. His genus Squalus, therefore, included the Carcarhidae, Galeidae, Lamnidae, Alopecidae, Rhinodontidae, and Symnidae of Muller. In Mr Owen's table, the Spinacidae, Lamnidae, Alopecidae, and Symnidae are separated from the Squali of Cuvier, and the remainder of that group are denominated, after Muller, Nyctantantes, which are chiefly, therefore, Carcarhidae and Galeidae. The presence of a nictitating membrane to the eye is accompanied with a greater indication of the skeleton. This membrane, as it exists in Galeus, is superadded to a well developed circular palpebral fold of the skin. A superficial membrane or conjunctiva is reflected from the circular eyelid over the third eyelid, which is placed on the nasal side of the orbit. The third or nictitating eyelid is raised, and the upper part of the circular one depressed at the same time by muscular action when the fish wishes to close the eye. In our arrangement of the genera, we have generally followed the Plagiostomata of Muller and Henle, whose generic characters we have abridged, not having access at present to Muller's later works.

The Carcarhidae are armed with teeth which, by their arrangement in a linear series, make a sharp saw, each tooth in the majority of species being also serrated on the edge. The common form of the upper teeth is that of the tip of a lancet, frequently oblique, one shoulder of the lancet being more curved than the other. The teeth of the lower jaw are either similar to the upper ones, or have narrower cusps, according to the species. Each jaw supports several rows of teeth, the anterior row on the edge of the jaw being erected for use, and the posterior ones lying flat in the hollow of the cartilage, and coming forward in succession as they are required by the decay and loss of the front ones. No animal possesses a more perfect incisorial apparatus than these massive but powerfully active tyrants of the deep. They have been known to divide the body of a man in two at one bite, as if by the sweep of a sword, and we once had an opportunity of observing how clean a cut a Shark's jaws were capable of making. A piece of salt-beef weighing about 14 lbs. was hanging over a ship's stern, suspended by a strong cord in a net of sinnet. Sinnet is the sea term for a flat plat of rope yarns, more pliable but equally strong with rope containing the same quantity of material, and, from its looseness of texture, capable of stretching more, and less easily cut. In this instance, the sinnet forming the meshes of the net was of the wideness of two fingers' breadth. The beef just dipped below the surface of the water or rose above it, as the ship's stern rose and fell with the gentle swell of a tropical sea. Suddenly a Shark came up from the deep, and before the spectators could raise the beef on which a hungry party hoped to make a dinner, the monster turned his mouth gently upwards, and, without plunge or struggle, carried off the beef and half the net to the depths into which he immediately descended. The sinnet was cut evenly across as if with a razor. Had it been torn by the mere weight of the fish, the rope yarns would have hung out of unequal lengths, and the seamen considered that on exposure to a simple strain, the rope by which the net was suspended would have broken long before the net itself gave way. A Shark killed near Marseilles, is alleged to have had the entire body of a man and several fish in its stomach; and one captured off Santa Margareta is said to have contained the carcass of a horse. Its weight was 1500 pounds. The cartilaginous jaws of Sharks shrink at least a third in drying; and cannot, as they lose their moisture, be kept at full stretch without tearing, yet specimens are not very rare in museums which may be slipt over a stout man easily. The widest jaws usually met with are those of *Carcharias*, *Oxyrhina*, *Selache*, and *Odontaspis*.

Of the *Galeidei*, or *Topes* and *Hounds*, we have two British examples, one the *Galeus canis*, named by the fishermen of different localities, "Penny-dog" and "Miller's Dog," but more generally the "Topes," an appellation which Araldi says is Cornish. *Galeocerdo arcticus* is a northern species that frequents the seas of Petoe, Iceland, and Norway; another species of the same genus inhabits the Indian Ocean. The *Mustelus levis*, or *vulgaris* of Müller and Henle, is frequent enough on the British coast. Its flat pavement-like teeth indicate crustaceans as its chief food, which they are adapted for crushing. It gives less trouble to the fishermen than the other Ground Sharks, which are constantly taking his bait or driving away the fishes he is desirous of catching. Its rich diet improves the quality of its flesh, which is considered in the Orkneys to be more delicate than that of the Sea-dogs or *Scylla*.

**Lamnidae.** Of this family the *Lamna cornubica*, so well known on the southern coast of England, and the only member of its own genus, is an example. It is, from its size and its dentition, the most formidable of the Sharks of common occurrence in the English Channel. One caught in 1834, off the coast of Caithness, and now in the College Museum of Edinburgh, measured eight and a half feet in length and four feet eight inches in circumference. Its teeth are upwards of an inch in length, flatly compressed, thin-edged, but not serrated; in outline each tooth is triangular, and the older teeth have one toothlet sometimes at the base on each side. In the upper jaw, the tooth which follows the first two is smaller than them or than the one which succeeds it. In *Oxyrhina* the teeth near the symphysis are long and strong, like spike-nails, tapering to a point and slightly curved; anteriorly they are flat, and posteriorly convex. They are the most formidable-looking teeth that any of the existing Sharks possess, but are calculated rather for holding and tearing their victims than for sawing or cutting. *Selache maxima* is a northern species that frequents the Greenland and Spitzbergen seas, and descends in the summer to the coasts of New Jersey on the American side, and to the British Channel on the European side of the Atlantic. The teeth are comparatively small, and the habits of the fish, as far as known, are not remarkable for rapacity. In the numerous instances in which it has been captured on the coast of Scotland, nothing has ever been found in its stomach but fragments of sea-weed. It attains a large size, growing to thirty-six feet or more, but it is indolent and not very sensible to slight wounds. It is often seen lying on the surface of the water with its dorsal fin raised in the air, whence it has obtained the names of Sail-fish, Sun-fish, and Basking Shark. While thus reposing, it may be easily approached by a boat and harpooned. It enters the bays on the northern shores of Great Britain in the months of June and July, sometimes in numbers but more commonly in pairs, and retires on the approach of cold weather. It is a profitable capture, since eight barrels of fine oil have been procured from the liver of a full-grown fish. Sir Everard Home described much of the anatomy of this fish, with the help of Mr Clift who was the operator, but Sir Everard was mistaken when he referred the supposed Sea-snake, driven on shore in the Orkneys in 1808, to be this species. The enormous length of the Orkney animal, the smallness of its head and of the adjoining vertebrae, still preserved in the Museum of Edinburgh University, prove it to have been some great cartilaginous fish yet to be made properly known to naturalists. The parts that were saved were described by Dr Barclay in the *Transactions of the Wernerian Society*.

The *Alopecias vulpes* is distinguished from the rest of the sub-order by the extreme length of the upper lobe of its tail, exceeding that of the body. It is from the resemblance of this fin to the long brush of a fox, that Mr Yarrell ascribes the origin of its appellation of Sea-Fox, a name by which Aristotle makes mention of it, and which has been handed down to us by Ælian and Pliny. It generally receives the name of "Thresher" from seamen, on account of its attacking the whale, and striking it violent blows with its tail. Mr Yarrell (i., p. 144) gives a lively account of a combat of this kind, in which a party of Threshers, assisted by a Sword-fish, had nearly mastered a whale when the observer lost sight of them. The species attains the length of at least fifteen feet; but its jaws are not constructed for swallowing a prey equal in bulk to that which a *Carcharias* of equal length would ingulf.

**Cestracions.** This family contains only two species, and perhaps only one, for the difference between the *Cestracion zebra* of Japan and the *Cestracion philippi* of the Australian seas, hitherto ascertained, are chiefly those of patterns of colour, which are certainly very dissimilar in fishes taken in the two localities. Müller and Henle considered them to be mere varieties of one species, and it is to be wished that some competent ichthyologist who has an opportunity of seeing recent specimens from both places, would strictly compare one with the other. The genus is one of much interest to geologists, as the fossil teeth of Cestracions are of older date than those of any other existing genus of fishes. The *Cestracion* received the name of the "Nurse" in Australia, and the Chinese call it "Cat-Shark" or "Kitten-Shark." Specimens of the young are often found in the Canton insect-boxes.

*Hexanchus griseus*, one of the *Notidaniidae*, inhabits the Mediterranean Sea, but occasionally strays to the English shores. The British Museum possesses one taken off the Isle of Wight.

The *Acantias vulgaris*, the spined Dog-fish, is another of the Sharks that is confined to no one district of the ocean. It is found on both sides of the Atlantic, N. and S., in the Mediterranean, and in the South seas. It is very common in the British seas; and, according to Mr Couch, as quoted by Yarrell, sometimes occurs in almost incredible numbers, 20,000 having been taken in a scan, at one time, on the coast of Cornwall. It does much injury to the fishermen by cutting their lines and carrying off their hooks.

The Hammer-headed Sharks, *Zygoma* or *Sphyrna*, are very plentiful in the Bight of Benin, and are considered to be more blindly voracious than others, and therefore more dangerous. They may be often seen ascending from the clear blue depths of the ocean like a great cloud. The extraordinarily elongated orbits are flexible in the early stage of the fish's development, and in the fetus are doubled in upon themselves, so that the head occupies less than half the space it would otherwise do; neither does the head attain its final shape till the fish is grown to a considerable size. These fetal specimens, from their convenient size, of a foot in length or so, are the most common in museums, and have given rise to some misapprehension respecting the true shape of the head of the adult fish; and as the transverse distance between the eyes becomes proportionally greater with the age of the fish, several nominal species have been introduced into our lists. M. Valenciennes (*Mem. du Mus.* ix.), in a dissertation on this genus, has given the forms of the heads of several; and in the Supplement to Mr Yarrell's *British Fishes*, an outline of the head of a young specimen of *Sphyrna Blochii*, copied from M. Valenciennes, and one of an older fish captured by Dr Cantor, are placed side by side, and show well the remarkable change of form which age produces, for *Sph. Blochii* and *laticeps* are the same species. A female *Sph. Zygoma*, measuring nearly eleven feet, examined by the active naturalist just named at Penang, contained thirty-seven living young. This species is almost cosmopolitan, having been taken in the ORDER XI.—PLAGIOSTOMI.

Endo-skeleton cartilaginous or partially ossified; exo-skeleton placoid. Gills with five or more apertures. No swim-bladder. Scapular arch detached from the head. Ventral abdominal; intestine with spiral valve. Cephalic gland.

Sub-Order I.—SQUALI.

Plagiostomes, with lateral gill-openings. Free supplementary eyelids; incomplete scapular arch; and no naso-pectoral cartilage.

ANALYTICAL TABLE OF THE SQUALI (Dum.)

Pectorals not notched. Head short, obtuse; teeth tricuspid; gill-openings over pectorals. SCYLLIUM. Spout-holes none. Forehead abnormal, wide, eyes laterally stilted. ZYGENA. Forehead of the usual squatinoid form. Gill-openings before the pectorals. LAMNA. Gill-openings over the pectorals. CARCHARIAS. Spout-holes present. Teeth serrated, denticulated. Dorsals two. GALEUS. Dorsal solitary. NOTIDANCE. Teeth not denticulated. Teeth flat. Anal distinct. Dorsal pointed. MUSTELUS. Dorsal rounded. CESTRACION. Anal wanting; dorsals with spines. SPINAX. Teeth not flat. Teeth tranchant. Dorsals with spines. CENTRAINA. Dorsals without spines. SCYMNUS. Teeth conical, pointed, very numerous. SELACHUS. Pectorals notched in front, affording space for the gill-openings. SQUATINA.

(A.) Sharks, with an anal fin, and the dorsals far back; the first being behind the ventrals.

FAMILY I.—SCYLIIDÆ.

Scylios, Müll. and Henle. Spout-holes. No nictitating membrane. Five gill-openings, the last one over the base of the pectoral fin. A furrow at the corner of the mouth; an upper and lower labial cartilage. Teeth with a pointed medial cusp, and four or five smaller toothlets on either side. Caudal longitudinally extended, transversely or rounded at the end, with or without a trace of an under lobe, but having a notch on the under side near the end; no caudal pit; oviparous. Eggs resembling those of a Skate; intestinal valve spiral.

GENUS I. SCYLLIUM, Müll. and Henle. First dorsal between the ventrals and anal; the second between the anal and caudal. Spout-holes close behind the eyes. Gill-openings equidistant, the last pair over the pectoral. Snout short, blunt; nostril near the mouth, connected with it by a furrow, and having a valve. Dermal osicles or scales tricuspid. Eleven species.

GENUS II. PRISTIURUS, Bonap. Scylios, but with an elongated snout. Upper edge of the caudal serrated by a row of flat spinelets; a trace of an under caudal lobe; second dorsal over the end of the anal. Eggs similar to those of Scylios. One species.

GENUS III. HEMISCYLIUM, Müll. and Henle. Nostrils reaching to within the mouth; nasal flaps distinct, outer one large, inner one with a barbel. Spout-holes large, longitudinal under the hinder half of the eyes. Gill-openings as in Scylium. Both dorsals behind the ventrals and before the anal, which latter is close to the caudal; caudal notched, without an under lobe. Two species, see fig. 11.

GENUS IV. CHILOSCYLIUM, Müll. and Henle. A broad cutaneous under lip, with a transverse furrow behind it; the elongated under fold at the corner of the mouth attached in the middle. Teeth pointed, with one or two radical toothlets on each side. Spout-holes longitudinal, close behind the eyes. Fourth and fifth gill-openings close together. Dorsals placed as in Hemiscylium. Six species.

GENUS V. CROSSORHINUS, Müll. and Henle. Mouth large, nearer the end of the snout than in most Sharks. Head broad and flat; many cutaneous tags about the nasal flaps and sides of the head. Teeth trilobate. Spout-holes unusually long, beneath and somewhat behind the eyes. Gill-openings equidistant, decreasing in size from first to the last, which is over the pectoral. Dorsals between the ventrals and anal, the latter close to the caudal. One species.

GENUS VI. GINGLYMOSTOMA, Müll. and Henle. (Nebria, Rüpp.) Snout blunt; a long barbel from the inner side of the nostrils; corner fold of the mouth divided by a deep transverse furrow, the hinder portion subdivided by a longitudinal furrow. Teeth very numerous, in seven successive rows, each having a simple rhomboidal base, a conical medial point, and from two to four toothlets on each side. Fifth gill-opening almost concealed within the fourth. Spout-holes very small, directly behind the eyes. First dorsal over the ventrals; caudal very long, having a rudimentary under lobe; pectorals long. Two species.

GENUS VII. STEGOSTOMA, Müll. and Henle. Mouth small, quite transverse. Teeth small, tripartite. The skin between the nasal flaps wider than the flaps, and forming an outer upper lip. A stout barbel, formed by a prolongation of each nasal flap. Corner folds of the mouth short, with deep pits. Head depressed and rounded. Spout-holes and circular slits behind the eyes. Fifth gill-opening concealed within the fourth; the last three over the pectoral; caudal very long, almost of even height throughout, and notched as usual towards the end. One species.

(B.) Sharks, with two dorsals and an anal; the first dorsal over the space between the pectorals and ventrals. Nictitating membrane. No spout-holes; the last two gill-openings over the pectoral.

FAMILY II.—CARCHARIDÆ.

Carcharias, Müll. and Henle. Nostrils generally small, with a three-sided flap on their upper border. Pupil perpendicularly oval. Mouth boldly convex, with a small corner fold. Teeth compressed, triangular, with an entire or serrated cutting edge. Caudal always with a short under lobe, and a notch below near the end of the upper lobe. A pit above and below at the base of the tail. Intestinal valve rolled longitudinally, not spirally. Scales small. Skin smoothish.

GENUS I. CARCHARIAS, Müll. and Henle. Nostrils midway between the mouth and end of the depressed snout. Labial cartilage small or wanting. Tail long connected with a kind of uterine placenta; oviduct smooth or villous.

Sub-Genus I. Seliodon. A medial tooth in the upper jaw, none in the lower one; cutting edges of the teeth entire, not serrated. Second dorsal over the anal or its hinder end. Tail-pits distinct. Upper and lower caudal lobes equal. Scales small, three-keeled. Oviduct villous. Three species.

Sub-Genus II. Pseudon. Teeth like those of Seliodon, but thicker and larger, and there are two small teeth on the mandible, opposed to the single medial upper tooth. First back fin close before the second, the second over the anal. One species.

Sub-Genus III. Hypion. Teeth not serrated; upper teeth straight or slightly inclined backwards; under ones straight, with a small point on a broader base. Three species.

Sub-Genus IV. Hypion. Both of the upper teeth strongly serrated or jagged on one or both sides; their cusps smooth; no serratures on the bases or points of the lower teeth. Two species.

Sub-Genus V. Prionodon. Teeth in one or both jaws finely serrated, oblique or straight, three-sided, or with a small cusp on a broad base; generally a solitary medial under tooth. Oviduct smooth. Twenty species.

GENUS II. PRIONODON, Müll. and Henle. (Leptocarchas, Smith.) Nasal flap broad or prolonged into a barbel. Orbits longitudinal. Corner folds of the mouth very small. Teeth of Scylios, small and numerous, alike in both jaws. Second dorsal and anal opposite, or nearly so. Caudal as in Carcharias, or as in those Scyliodes, in which the under lobe is scarcely perceptible. Scales from three to seven keeled. Two species.

(C.) Sharks, with two dorsals and an anal; first dorsal between the pectorals and ventrals. A nictitating membrane. Spout-holes. The last two gill-openings over the pectoral.

FAMILY III.—GALEIDÆ.

Galei, Müll. and Henle. Nostrils, orbits, mouth, and its corner folds as in the Carcharidæ, but with small labial cartilages. Spout- Classifications—Sharks.

Genus I. Galeus, Cuv. Spout-holes longish, half the length of the orbits behind the eyes; pupil round above, angular below. Teeth smooth on the inner edge, serrated on the outer one; cusp smooth, upright; medial teeth straight, jagged at the base on both sides, and as large as the others. No tail-pits. A notch on the upper caudal lobe. Intestinal valve spiral. Two species.

Genus II. Galeorhinus, Müll. and Henle. Spout-holes very small, half the length of the orbits behind the eyes; pupils as in Galeus. Corners of the mouth and labial cartilages indistinct. Teeth denticulated on both edges; outer edge prolonged in form of a coarsely jagged base; a single medial tooth on both jaws, with the point turned to a side. Upper caudal lobe long and pointed; two notches on the under caudal border, one of them at the end of the spine. A tail-pit above and below. Gut-valve rolled lengthways. Two species.

Genus III. Loxodon, Müll. and Henle. Pupil round. Teeth alike in both jaws, oblique-edged, not serrated, basal projection on the outside also entire; a medial tooth in the upper jaw, none in the lower one. Spout-holes small, close behind the eyes. Tail-pits above and below. A single notch in the upper caudal lobe. One species.

Genus IV. Thalassodon, Valenciennes. Pupil perpendicularly oval. Nasal flap very short. Teeth triangular, without a serrated basal ledge. Spout-holes pretty large. Tail-fin in Carcarhinus, with a single notch; tail-pits above and below conspicuous. Intestinal valve rolled lengthways. Two species.

Genus V. Triakis, Müll. and Henle. Head flat, blunt. Nasal flap broad, moderately long; large pits at the corners of the mouth. Labial cartilages. Spout-holes of medium size, Teeth and fins as in Sphyrna. Under caudal lobe indistinct. Tail-pits wanting. Scales three-keeled and three-pronged. One species.

Genus VI. Mustelus, Artedi. Large spout-holes. Long orbits. Nictitating membrane puffing out at the under eyelid. Teeth pavement-like, with a central cusp or cutting edge, resembling those of the Rajidae. Labial cartilages at the corners of the mouth, and also deep pits. Nostril bordered above by a three-sided cutaneous lobe with a rounded tip and a short blunt lobe on the outside. First dorsal nearly in the middle between the pectorals and ventrals; caudal short. Tail-pits indistinct. Intestinal valve spiral. One species.

(D.) Sharks, with two dorsals and an anal; the first dorsal over the space between the pectorals and ventrals. Spout-holes, but no nictitating membrane.

Family IV.—Lamnidae.

Lamna, Müll. and Henle. Gill-openings large, all anterior to the pectorals. Second dorsal and anal roundish, of equal size, and opposite to one another. Tail-pits evident. Caudal crescentic. Tail keeled on the sides. Spout-holes very small. Intestinal valve spiral.

Genus I. Lamna, Cuv. Snout a pointed three-sided pyramid; nasal flap short, three-sided. Spout-holes very small, far behind the eyes. Teeth compressed, not serrated, triangular, with an acute basal toothlet on each side of the older ones; surface of the base that rests on the jaw deeply concave; in place of medial teeth, a vacant space above and below. Skin smooth. Scales very small. One species.

Genus II. Oxyrhina, Agassiz. Snout, spout-holes, and fins of Lamna. Teeth very thick, narrow and long, nail-shaped, curved, without basal toothlets; each tooth flat before, convex behind, diminishing rapidly in size towards the corner of the mouth, and double rooted with a deep notch between the roots; a vacant medial space on both jaws, and the third tooth of the upper jaw smaller than its neighbour. Three species.

Genus III. Carcharhinus, Müll. and Henle. Snout, position of fin and spout-holes, as in Oxyrhina. Teeth of Carcarhinus, but straight, equilateral, and without a basal ledge; no medial tooth; the third upper tooth is a little smaller than the adjoining ones. One species.

Genus IV. Selachus, Cuv. Snout short, blunt; spiracles small. Gill-openings very large, nearly meeting on the throat. Teeth very small and numerous, conical, without toothlets or lateral notches, curved backwards. Scales small, with radiating curved points, so that the skin feels rough to the finger drawn over it in any direction. One species. S. maximus.

Genus V. Odontaspis, Agassiz. (Triakisodon, Müll. and Henle.) Gill-openings large, wholly before the pectorals. Spout-holes very small. Transverse folds on the throat; a stout triangular flap above the nostril; no upper corner fold to the mouth. Second dorsal and anal large; upper caudal lobe elongated as in Carcarhinus. Tail-pits indistinct or wanting. Fore teeth very long, conical, simple, or with one or more very sharp basal toothlets; toward the corners of the mouth the upper teeth are more incisorial and diminish rapidly in size; the lower teeth are smaller in form; roots of the tooth divided into two branches by a middle hollow. Second dorsal over the space between the ventrals and anal. Scales three-keeled, the keels ending in sharp points. Two species.

Family V.—Alopecidae, Müll. and Henle.

Snout short and conical; spout-holes very small; nostrils small with a short superior flap; no labial cartilages. Gill-openings small in Carcarhinus; the last ones over the pectoral. Teeth compressed, not serrated on their cutting edges, alike in both jaws; no tooth on the median line; a smooth crescentic field of skin behind the upper teeth. Second dorsal opposite to the anal, very small; pectorals falcate; upper caudal lobe very long, with a pit at its root. Scales small, three-pronged. Intestinal valve spiral.

Genus I. Alopecias, Müll. and Henle. (Alopias, Rafinesque.) Teeth having the outline of a sharp isosceles triangle in both jaws. Upper lobe of the tail as long as the body. One species. A. vulpes.

Family VI.—Cestraciontidae.

Cestraciontus, Müll. and Henle. Mouth at the fore end of the snout. Nostrils slit to within the mouth. Spout-holes distinctly visible, rather behind the eye. Gill-openings small, the last one above the pectorals; a spine forming the front of each dorsal. Tail short; its upper lobe notched underneath. Pavement-like teeth in rounded oblique scrolls, like the spines of some univalves. One species.

Genus I. Cestracion, Cuv. Caudal wide, and strongly notched below. Two species, Pacific Ocean, from Japan to Australia.

Family VII.—Rhinodontidae, Müll. and Henle.

Rhinodon, Müll. and Henle. Head flat. Mouth and nostrils at its extremity; nasal flap triangular. Teeth extremely small, and very numerous, card-like, conical. Spout-holes very small. Gill-openings diminishing in size as they recede from the head; the last one above the pectoral. Caudal crescentic, its upper lobe not notched. Lateral keels on the keel and pits. Intestinal valve spiral.

Genus I. Rhinodon, Smith. One species.

(E.) Sharks, with one anal and only one dorsal.

Family VIII.—Notidanidae, Müll. and Henle.

Galeus, without a first dorsal. Upper corner-fold of the mouth very large, under one small; no nictitating membrane. Spout-holes vertical, small. Six or seven gill-openings, decreasing gradually in size, all before the pectorals; second upper tooth; towards the corners of the mouth the upper teeth are low and flat; the others are triangular above, serrated below, the foremost ones crowded and curved. A small inferior caudal lobe, obliquely truncated and notched at the rear. No tail-pits. Intestinal valve spiral.

Genus I. Hexanchus, Rafinesque. Six gill-openings. One species.

Genus II. Heptanchus, Rafinesque. Seven gill-openings. Two species.

(F.) Sharks, with spout-holes. Two dorsals; no anal; no nictitating membrane. Five gill-openings, all before the pectorals. Intestinal valve spiral.

Family IX.—Spinacidae, Müll. and Henle.

Each dorsal fringed by a spine.

Genus I. Acantias, Bonaparte. Head flat. Large pits at the corners of the mouth. Two labial cartilages. Mouth very flatly arched. Spout-holes large, behind and rather above the eyes, with a thick border springing from their fore edges; spout-holes large. Teeth on both jaws incisorial, the edge almost horizontal, with the point directed laterally, and the back keeled internally. First dorsal over the space between the pectorals and ventrals; second dorsal between the ventrals and caudal; upper caudal lobe the bigger one. An upper tail-pit in some. Male claspers tipped by a moveable spine. Scales heart-shaped, with a middle cusp and one or more keels. Four species. Genus II. Spinax, Bonap. Head arched. Snout blunt; nostrils at the extremity of the snout. Folds at the corner of the mouth very large, naked; under one encircling the under lip and uniting with its fellow; a labial cartilage at the upper corner of the mouth. Under teeth as in Acantias, but without keel and basal apophysis; upper teeth as in Scyllium, but with a longer, straight, conical, equilateral cusp, and two pointed lateral toothlets on each side. No tail-pits. Claspers not furnished with a prickle. Curved hairs in place of scales. One species.

Genus III. Centrina, Cuv. Snout short, thick, and flat, with the nostrils near its edge; nasal flap quadrilateral. Fold at the corner of the mouth naked, blending on the median line with the rest of the integument. Spout-holes very large, behind and somewhat above the eyes, vertical, and crescentic, with a single flap. Upper teeth slender, conical, straight, and feebly incisorial, connected with the integument of the front of the jaw, and notched in the middle of their base; under teeth very nearly straight, broader and flatter than the upper ones, keenly cutting, sub-equilateral and finely serrated, with their bases nearly quadrangular; medial tooth single, perfectly equilateral. Dorsal spines enveloped in skin to their points; no under caudal lobe and no notch. Male claspers armed, scaleless. Scales consisting of an upright cusp on a quadrangular base. One species.

Genus IV. Centrophryllum, Müll. and Henle. Head flat. Nostrils near the end of the snout. Folds at the corner of the mouth naked, large, and deep, with a slit running backwards from them. Spout-holes behind and above the eyes, furnished with a flap. Fourth and fifth gill-openings near each other. Teeth of the under jaw as in Acantias, and either serrated or entire; their roots a middle upright keel with a transverse exterior lobe; upper teeth straight, equilateral with quadrangular bases traversed by two crossing keels, no denticulations, no accessory prongs or toothlets; no medial tooth. No tail-pits. Male claspers with an external prickle near their tips. Two species.

Genus V. Centrophycillum, Müll. and Henle. Upper and under teeth similar, straight, pointed with one or two lateral cusps or toothlets, as in Scyllium. Distinguished from Scyllium by the teeth being alike in both jaws. Scales pointed, with a stellate base. One species.

Family X.—Scymnidæ, Müll. and Henle.

Scymnus, Müll. and Henle. Dorsal fins without spines. Upper teeth pointed; lower ones trenchant, not denticulated. No tail-pits.

Genus I. Scymnus, Cuv. Head either flat, or compressed on the sides. Spout-holes far behind the eyes. Teeth of the upper jaw upright, curved; under teeth broader, with an upright or an inclined edge. Gill-openings small. No tail-pits.

Sub-Genus I. Scymnus, with lanceet-shaped under teeth, convex anteriorly, sharp on the sides, rising from a high base; the medial tooth below the lateral so much larger, and a globoid root longer than the cusp; upper teeth standing straight forwards, with their sides inclined outwards. Claspers without a prickle. Two species.

Sub-Genus II. Lamargus, Müll. and Henle. Upper teeth small, longer than wide, conical, feebly incisorial, without serratures; an upright anterior keel, and a notched base; under teeth broader and longer, with a recumbent edge as in Acantias, no serratures; and a long flat root, concave lengthways, and keeled perpendicularly anteriorly. Male claspers with a prickle. Three species.

Genus II. Echinorhinus, Blain. Goniodes, Agass. Head flat; corner-plug of the mouth widely apart. Teeth broad and low, with a nearly horizontal edge; on the lateral edge, from one to three small cusps or toothlets; a space at the symphyses of the under jaw, with a very small medial tooth in its centre. First dorsal over the eyes; no under caudal lobe. Gill-openings not wide, all before the pectorals. One species.

Genus III. Pristiothorax, Müll. and Henle. Separated from Pristi by the want of a naso-pectoral cartilage, the posterior wall of the nose being in this genus formed by the skull itself. Snout greatly elongated, beset on both sides with spines, attached to the skin only. A long barbel from the under surface of the snout. Mouth transverse. Teeth pavement-like, with a short medial cusp, as in the male rays. First dorsal over the space between the pectorals and ventrals. Side of the snout keeled. Fourth and fifth gill-openings approximating. Two species.

Family XI.—Squatiniidæ.

Squatina, Müll. and Henle. Body flat above and below. Mouth at the extremity of the snout. Eyes on the dorsal aspect. Spout-holes large, behind the eyes. Pectorals large, their expanded roots interposing between the head and body, but divided from them by a furrow, in which are situated the closely approximated gill-openings.

Genus I. Squatina, Dum. Both dorsals on the tail, which is keeled on the sides. Male claspers small and weak. Scales conical, with a terminal point. Teeth conical, irregular, with interspaces. Two species.

(G.) Sharks, similar to those of division B, in having a nictitating membrane and no spout-holes, and in the position of the spinelike dorsals; but with a lateral extension of the skull at the orbits, which is greatest in the adults.

Family XII.—Zygénidæ.

Sharks, head flat, with the orbits largely extended latterly, and the snout truncated, or hammer-headed; a form of head not found in any other group of fishes.

Genus I. Zygène, Cuv. (Sphyrna, Rafin.) Sphyrnae and Sphyrna, Rafin. Front of the head transverse to the ends of the lateral orbital extensions of the skull. Nostrils on the front border; nasal flap small, triangular on the inner edge of the nostril. Labial cartilages small. Teeth alike above and below, being a compressed pyramidal, with an entire or serrated exterior basal edge; a medial tooth in both jaws. First dorsal near the pectorals; second one over the anal. Distinct tail-pits. Oviduct villous; yolk-bag connected to the sides of the ovary. Four species.

RAYS.

This sub-order, familiarly known by the name of Skates, has for the general character of its form the extreme depression of its body, and the lateral expansion of the pectoral fins forming a discoid or subrhomboidal body, with an appended tail, which in the *Rhinobatidae* is fleshy and tapering, and in the *Rajidae*, *Trygonidae*, and some other groups, is cartilaginous and slender, and sometimes elongated like the thong of a whip. In some a narrow lanceet-shaped spine placed erect on the dorsal surface of this whip-like tail, with its cutting edges turned sideways, proves a dangerous offensive weapon, which the fish can use with great effect. The cartilaginous scapular arch is complete on the ventral surface, and running forwards at some distance, laterally from the skull in a crescentic tapering point, gives support to the long, jointed cartilaginous rays of the pectoral. In the space between the hinder horns of the scapulo-coracoid cartilages laterally, and the pelvic cartilages behind, lie the abdominal viscera; while the branchial apparatus and vascular centres occupy the posterior part of the spaces between the anterior cornua of the scapular arch and the narrow skull. On looking at the skeleton of a Skate, it will be seen that the skull is comparatively narrow; that the cartilages supporting the branchial apparatus stand out like wings behind, and those on which the eyes are placed also project laterally, exactly like the prominent orbits of the *Zygana*, but that this lateral prominence is concealed in the entire Skate by being inclosed between the points of the pectorals. Anteriorly the skull is completed by a tapering cartilage whose tip supports the end of the snout. In the *Torpedinidae*, a cellular galvanic battery fills up the wide spaces between the skull cartilages and the front horns of the pectorals. Recently a homologous apparatus, but much smaller and merely rudimentary, has been discovered in the ordinary Skates—an indication seemingly of a general plan of structure in the members of the group, irrespective of function, which it has pleased the Great Architect of the Universe to give.

Except in the genera *Anacanthus*, *Aetobates*, and *Myliobates*, we are not aware of any species of Ray that is common to both the Atlantic and Pacific districts of the ocean, but several exist both in the Mediterranean and North seas. *Anacanthus africanus* has been taken both in the Red Sea and in the Gulf of Guinea. *Myliobates Nieuhoffi* exists in the Mediterranean, and in the Indian and Australian seas, and *Aetobates narinaris* frequents the coasts of Brazil, as well as the Red Sea and the Indian Ocean. Of the range of species, however, we are not prepared to speak with confidence. What is at present known on the subject rests chiefly on specimens in the European museums, examined by Müller and Henle, whose work on the *Plagiostomi* is the only one professing to include all the known species. The great advances that ichthyology has made since the publication of that work, and the attention now paid to anatomical structure in the definitions of species, will enable future ichthyologists to enter on the inquiry of distribution of species with great advantages. The Rays found on the British coasts are *Torpedo marmorata*, and *T. nobiliana*, of only occasional occurrence, and much more abundant in the Mediterranean: *Raia radula*, *R. clara*, *R. radiata*, *R. batis*, *R. margarita*, *R. fullo*, *R. oxyrhyncha*, *R. microcellata*, *R. intermedia*, *R. lutea*, and *R. acus*; *Cephaloptyera Giorna*, *Myliobatis aquila*, and *Trygon pastinaca*. Some of these are of daily occurrence in our markets, as the *R. batis*, Blue or Grey Skate, Tinker or True Skate. The *R. oxyrhyncha* (L.), or *miraleta* (Yarr. Ed. 2nd), Homelyn, Spotted Ray, or Sand Ray, is stated by Mr Yarrell to be one of the two commonest Skates brought to the London market; the other being the *R. clara*, Thornback, Young Maidens, or Maiden Skate. Unlike most fish, the Skate improves by keeping several days, being hard and tough when cooked soon after it is caught. It is one of the fish that the fishmongers are in the habit of crimping. Figure 7, p. 123, represents the *Raia Lengueri*, an Australian Skate, which somewhat resembles the Homelyn of our own coasts in general form, and fig. 136 shows the under surface of its head.

Some of the *Cephalopteridae* attain an enormous size. One mentioned by Risso, taken off Messina, weighed 1250 lbs.; the male is usually the smallest. Of a pair spoken of by this author, the female was first taken, and the male remained hovering about the boat for three days, and was afterwards found floating dead on the surface. But the size here spoken of is greatly surpassed by other fishes of this order, which have been but imperfectly described, such as the *Raia Banksii* of Lacépéde, referred with doubt to the genus *Ceratopteryx* by Müller and Henle. A fish of this kind taken at Barbadoes required seven yoke of oxen to draw it. A sketch of another, which was said to be 20 feet long, was sent to Lacépéde; and Levallant, in his second voyage to Africa, speaks of one which swam round the vessel, and appeared to be about 25 feet long and 30 wide. Sonnini also mentions one which seemed to him to be longer and wider than the ship in which he was sailing.

The *Torpedinidae* all possess electric organs, and it is the space occupied by these batteries that gives the round or truncated outline to the fore part of the fish. The batteries lie one on each side of the head, bounded behind by the scapular arch, and laterally by the anterior crescentic tips of the pectoral fins. They consist of a congeries of vertical prisms, whose ends are in contact with the integuments above and below; and each prism is subdivided by delicate transverse septa, forming cells which contain a fluid, and are lined within by an epithelium of nucleated corpuscles. Between this epithelium and the transverse plates and walls of the prism, there is a layer of tissue, on which the extreme twigs of the nerves and vessels ramify. Hunter counted 470 prisms in each battery of the *Torpedo galea*, and demonstrated the enormous supply of nervous matter which they receive. Each organ receives one branch of the trigeminal nerve, and four branches of the vagal nerve, the former and the three anterior branches of the latter being each as thick as the spinal chord. The fish gives the electric shock voluntarily, when excited to do so in self-defence, or when roused to kill its prey; but to receive the shock the object must complete the galvanic circuit by communicating with the Torpedo at two distinct points, either directly or through the medium of some conducting body. The shock received on handling the fish is described as too strong to be willingly encountered a second time, and it is said that a painful sensation may be produced by a discharge conveyed through the medium of a stream of water.

**Sub-Order II.—RALE**

*Plagiostomi*, with flat bodies, spout-holes. Five slit-like gill-openings on the ventral aspect before the ventrals and under the pectorals. Eyes and spout-holes on the dorsal aspect. A complete scapular arch. Naso-pectoral cartilages. No eyelid, or an admate upper one only.

**Analytical Table of the Rale (Dum.)**

| Tail long, and | Very thick at the root. | | --- | --- | | Snout prolonged | Set laterally with teeth. | | | Pristis. | | | With even, thin, smooth edges. | | | Rhinobatos. | | | Snout rounded, smooth. | | | Rhina. |

**Slender**

| Dorsals two, caudal; disk rhomboidal. | Raja. | | --- | --- | | Dorsal single, anterior. | Eyes on the dorsal aspect. | | Teeth small; tail spiny. | Trygon. | | Teeth broad, fat, grinders. | Myliobates. | | Eyes lateral; head truncated, horned. | Cephalopterus. | | Tail short; body smooth; electric organs visible. | Torpedo. | Family I.—PRISTIDÆ.

*Pristidae*, Müll. and Henle. Form of Sharks, with the gill-openings on the ventral surface as in the Rays; characterized by a long flat narrow snout, set on the sides with strong bony spines, or teeth forming a saw, with two edges; true jaw-teeth like those of *Mystus*.

**Genus I. Pristis.** (*Pristisblaini*, Blain.) Six species.

Family II.—RHINOBATIDÆ.

*Rhinobat*, Müll. and Henle. Of an intermediate form between the typical Rays and the Sharks. Pore part of the body forming a disk by the conjunction of the pectoral fins with the snout; pectoral fins quadrangular, divided from the proper head part of the disk by a furrow, and not reaching back to the ventrals. First dorsal over the ventrals; caudal bilobate; upper lobe a little larger; the keels of the sides continued along the caudal fin. Margins of the mouth undulated; three protuberances of the under jaw fitting corresponding incursions of the upper one. Nostrils longitudinal near the mouth, with flaps.

**Genus I. Rhinina, Bloch, Schneid.** Snout broad, rounded. Spout-holes close behind the eyes. Nasal flaps reaching to the inner corner of the nostril. Undulations of the jaws broad. Teeth almost round, not broader than long. One species.

**Genus II. Rhynchorhyncha, Müll. and Henle.** Snout pointed, with a medial tapering keel. Spout-holes close behind the eyes; nasal flaps not reaching to the inner corner of the nostril, but only halfway. Undulations of the jaws feeble. Teeth broader than long. A transverse curved row of pores on the ventral aspect of the scapular arch. One species.

**Genus III. Rhinobatus, Bloch, Schneid.** Pectorals blending imperceptibly with the sides of the snout; the space between them and the skull cutaneous. Both dorsals on the hinder part of the tail; ventrals longer than the head, rounded before, pointed behind; no under caudal lobes. Mouth transverse, straight, or gently curved, with a medial keel; nostrils with a transverse ridge more or less acute. Spout-holes close behind the eyes. A row of pores on the scapular girdle. Two sub-genera, *Synbatus* and *Rhinobatus*, varying in the form of the nostril flap. Eighteen species.

**Genus IV. Trygonorhina, Müll. and Henle.** *Rhizobatus*, but the nasal flaps uniting with one another to form a single flap, which hangs over the mouth as in *Trygon*, leaving a round nasal aperture on each side. Upper eyelid adnate, crescentic; fore margin of the disk with a single incurvature. One species.

**Genus V. Platyrhina, Müll. and Henle.** Pectorals approaching one another at the point of the snout, and inclosing the front of the skull. Tail more slender than in the other *Rhizobatoides*. All the fins rounded. Upper nasal flap triangular, extending above the inner angle of the nostril. Upper eyelid as in *Rhinobatus*. No raised edge at the spout-holes. Two species.

Family III.—TORPEDINIDÆ.

*Torpedes*, Cuv.; *Torpedina*, Müll. and Henle. Tall short, less thick and fleshy than in the *Rhizobatoides*, depressed towards the end cylindrical, keeled on the sides. Disk naked, rounded, without scales or prickles. Ventral immediately behind the pectorals; dorsals near or near two of the tail; caudal sub-triangular. Upper eyelid adnate. A quadrilateral flap extends from the mouth between the nostrils, furnishing folds which embrace all the nostrils except its lateral corners; the flap is connected to the upper lip by a bridge. Teeth pointed or flat. A galvanic battery occupying the space bounded by the skull, gills, and pectorals. Teeth flat or cuspidate.

**Genus I. Torpede, Dum.** (*Narcobatis*, Blain.) Two dorsals. Disk rounded, anteriorly transected evenly or with a slight curvature. Mouth crescentic. Teeth pointed, attached to a jaw cartilage, and not extending outwards beyond the margin of the lips; base of each tooth widest transversely. Spout-holes at a distance from the eyes, with a cuticular fringe around the orifice. First dorsal bigger than the second one, and situated over the hinder part of the ventrals; caudal triangular with a straight terminal edge. Four species.

**Genus II. Narcine, Henle.** Two dorsals. Disk roundish, elliptical or angular, rounded in front. Mouth small, surrounded by a fold of skin which passes on the mesial line above into the bridge of the nasal flap; this flap is transverse, straight, or with a medial convexity, so as to become faintly three-lobed on the edge; a labial cartilage above and below. Teeth in quincuncial order, with a middle cusp, forming in the aggregate an elliptical plate, not adhering to the jaw, but moving with the skin; a velum within the upper jaw. Tail longer than the disk. Edges of the spout-holes not fringed. Five species.

**Genus III. Astrape, Müll. and Henle.** One dorsal. Snout short, without a keel. Mouth as in *Narcine*. A cylindrical cartilage in the bridge of the nasal flap. Cusps of the teeth on a quadrangular base; dental plates overhanging the border of the mouth a little; velum within the mouth, above and below. Spout-holes near the eyes, with smooth borders. Three species.

**Genus IV. Temera, Gray.** No dorsal. Mouth, eyes, and nostrils as in *Astrape*. Tail proportionally short. Spout-holes close behind the eyes, with smooth borders. Teeth flat. One species.

**Genus V. Discopyge, Heck.** Disk orbicular. Mouth transverse, with thick lips at the corners; upper jaw having a dental lamina, turning outwards, covered with minute teeth, in quincuncial order. Teeth flat, rhomboidal, their hinder angle acute. Nasal valve transmuted, with a notched process in the middle; beneath joined by a bridge to the circle of the mouth. Spiracles adjacent to the eye, with well-developed lips. Ventrales united under the tail; dorsals two, equal; caudal obsolete or wanting.

**Genus VI. Hemigaleus, Bleek.** Temporal openings minute, triangular; pupil convex above, narrow beneath. Premaxillary teeth serrated on their outer edge, smooth internally; mandibular teeth slender, with a broad base not serrated. Conspicuous caudal furrows above and below. Valve of the great intestine rolled up longitudinally. Batavia. Two species.

**Genus VII. Hypnos, Dum.** Disk lengthish, somewhat notched in the middle of the front border. Spout-holes close to the eyes, surrounded by a wreath of long and numerous fringes. No labial cartilages. Mouth crescentic, not protractive. Pointed teeth on the edge of the jaws, over whose whole length they occupy, but do not go beyond. Bridge of the nasal flap connected with the fore border of the upper lip. Tail extremely short.

Family IV.—RAHDE.

Disk broad, rhomboidal, the two sides which meet to form the lateral angle belonging to the pectoral fins; these are attached posteriorly, as far back as the root of the ventrals, and flank the point of the snout anteriorly; dorsals near the tip of the tail. Tail depressed, with a cuticular keel on the sides. Caudal wanting, or existing as a small cuticular seam. Upper eyelid adnate. Spout-holes marginal from the orbit; a slender cutaneous bridge, smooth-edged. Nasal flap confluent with the upper lip, forming an even surface, with a free rounded lobe on each side, which folds over the nasal aperture. Mouth carved, with its convexity towards the tip of the snout; no labial cartilages. Teeth of the males with a central cusp in spawning time; an upper velum only. Skin smooth, or studded with prickles pointed backwards, among which, chiefly on the dorsal ridge, and on the sides of the tail, there are often larger spines. In the males, sharp prickles are developed on the borders of the pectorals in the spawning season. Oviparous.

**Genus I. Raia, Cav.** (*Dasyatis*, Blain.) Snout keeled, with the anterior part of the pectorals parallel to the keel, but separated from it by a narrow space. Ventrales deeply notched behind, hence bilobate; anterior or outer lobes more narrow. Terminal caudal seam low, and more conspicuous above than below, generally interrupted at the point. Thirty species.

**Genus II. Sympterygia, Müll. and Henle.** Pectoral fins uniting before the head and forming the point of the disk as in *Trygon*. Ventrales not notched, being merely undulated posteriorly; caudal as in *Raia*. One species.

**Genus III. Uaptera, Müll. and Henle.** Snout and ventrales of *Raia*; no caudal. One species.

Family V.—TRYGONIDÆ.

*Trygonas*, Müll. and Henle. Point of the disk formed by the pectorals. Upper eyelid adnate. United nostril flaps free and fringed, but bound to the upper lip by a slender medial bridge; nostrils closely approximated under the flap. Skull higher than in the Rays. Spout-holes large and close behind the eyes. Teeth transversely elliptical, with a ridge which is blunt, sharp, or cuspidate. Ventrales not notched. Tail slender, often whip-like, without lateral keels; naked, or bearing one or more barbed spines. No caudal. Skin smooth or tuberculated, or prickly. No prickles are developed on the pectorals of the males, as in the Rays.

**Genus I. Anacanthus, Ehrenb.** No spine on the tail; which also admits a fin with rays but is either naked or furnished with a cuticular seam. Two species.

**Genus II. Trygonas, Adam.** (*Trygonobatus*, Blain.) Disk oval or rhomboidal. Tail equal in length to the body, or longer, bearing one or more spines without cuticular ridges, or with short ones merely, not reaching the point. Teeth cuspidate, or transversely ridged with cross furrows; upper velum deeply fringed with a second crescentic one behind; generally a papilla behind the under teeth. The species may be divided by the wholly finless condition of the tail, or the existence of a cuticular seam below, or of a seam above as well as below. Eighteen species. Genus III. Pterygoplathe, Müll. and Henle. Disk nearly twice as broad as it is long. Tail for the most part shorter than the body, bearing one or more spines, with low cuticular seams, or quite naked. Mouth crescentic, with the dental plate reaching to its corners. Teeth having from one to three cusps; upper velum not fringed; no papillae behind the under teeth. Skin smooth or tuberculated. Three species.

Genus IV. Tenuira, Müll. and Henle. Disk roundish. Tail little longer than the body, depressed before the spine, which is near its middle, compressed posteriorly, with a small under fin running from near the spine to the end, together with a shorter or longer cuticular hem above, also reaching the point. Nostrils approximating as in Trygon. Teeth with a transverse ridge or a cusp. Mouth straight or undulated. Upper velum straight. No papillae below. Five species.

Genus V. Urolophus, Müll. and Henle. Disk roundish, egg-shaped or rhomboidal. Tail destitute of a dorsal, but with a caudal which has cartilaginous rays, and reaches farther forwards below than above. Teeth and mouth as in Trygon; upper velum gently scalloped; under one with five warts. Four species.

Genus VI. Trygonoptera, Müll. and Henle. Tail short, broader at the end, with a small rayed dorsal immediately before the spine. Teeth rather acute. Disk as in Trygon. One species.

Genus VII. Aetoplathe, Valenciennes. A Pterygoplathe, except that it has a dorsal before the spine. One species.

Family VI.—Myliobatidæ.

Head more elevated than in Raja, projecting as far as the gills, beyond the pectoral disk, having no fin-rays on its sides, but a kind of head fin is developed before the skull, making the point of the disk. Nasal flaps forming the sides of a quadrangular flap which reaches to the mouth, and is fringed posteriorly; nostrils separated by a thin fillet merely, which comes from both angles of the mouth over the quadrangular flap, and is slightly pointed in the middle. Mouth transverse; dental plates reaching far back in the cavity of the mouth. Teeth large like mosaic pavement, even; upper velum very long, with a convex border fringed in the middle; under velum close to the teeth, with one pair papilla behind. Eyes and spout-holes in the sides of the skull; a broad bridge between the spout-holes and the eyes. No eyelids. Tail long, whip-like; a dorsal fin on its root, and a spine behind the dorsal.

Genus I. Myliobatis, Cuv. (Dicotyleus, Blain.) Union of the antecephalic rays of the pectoral forming a pointed snout; nasal flaps joined by a straight-edged membrane. Mouth transverse. Teeth arranged in a mosaic pavement of long hexagonal plates in the middle, and two or three rows of short quadrangular or hexagonal pieces on the sides; on the upper jaw the dental surface is convex both longitudinally and transversely. Five species.

Genus II. Aetomatis, Müll. and Henle. Snout pointed, not notched; under edge of the coalescent nasal flaps deeply notched; the nasal bridle papillose. Upper jaw straight-edged; crowns of the teeth in rows; the dental plates not extending to the sides of the jaws. Two species.

Genus III. Rajaportera, Kuhl. Snout deeply notched in the middle. The antecephalic fin in a lower plane to that of the pectoral, and joined to the inferior base of the latter. Nasal flap straight posteriorly; its lateral angles pointed. Jaws straight; teeth occupying the whole transverse breadth of the jaw, and forming from three to five rows of transversely narrow, antero-posterior narrow hexagonal plates, with smaller lateral ones as wide as they are long. Six species.

Family VII.—Cephalopteridæ.

Head straight transversely in front. The precepalic fins proceed from the under edge of the pectorals, and project like ears on the sides of the head, and curl upwards and inwards. Under edge of the coalescent nasal flap straight; nostrils near the precepalic fins, wide laterally. Teeth very small. Eyes on the sides of the skull immediately before the commencement of the pectorals. Spout-holes on the dorsal aspect, widely separated from the eyes. Tail as long, or longer than the body, bearing a dorsal fin, and behind it a spine.

Genus I. Cephaloptera, Dum. (Dicotyleus, Blain.) Mouth on the ventral aspect. Teeth of both jaws small, flat, pavement-like, of diverse forms. Pectoral fin prolonged forwards to a point beyond the truncated head, looking like a horn; the edge of the fin from this point to behind the eyes being convex. Four species.

Genus II. Ceratoptera, Müll. and Henle. Mouth at the end of the snout; upper jaw crescentic on the edge; under one convex; no teeth in the upper jaw; on the under jaw they are small and scale-like. Pectorals not passing the front of the head, a rayless space between the cephalic portion and the body of the fin; lateral edge of the fin incurred at the head, and spreading outwards at the third gill-opening. Three species.

In our preceding compendious review of the class of fishes, we have, as already stated, taken as our almost exclusive authority, with regard to structure, Professor Richard Owen, late Curator of the Museum of the College of Surgeons of London, and now Zoological Superintendent of the British Museum. From his lectures delivered in 1844 and 1846 before the college our facts have been taken. The great Histoire des Poissons of Cuvier and Valenciennes, which closed with the 22d volume in 1849, has been our text-book for the characters of families and genera of most of the osseous fishes, as well as for the few remarks we have made on their species. Several families and groups of families not included in that work have been characterized by the labours of Dr Kaup of Darmstadt; and for our analysis of the Plagiostomi, we have taken for our sole text-book the treatise of Müller and Henle on that subject, published in 1838. Some other works of Johannes Müller that we wished much to consult, were not to be found in those public libraries to which we had access, and we have been unable therefore to give the latest views of that very distinguished physiologist. We could not within encyclopaedic limits enter into the discussion of disputed points, or entertain questions respecting priority of names, and we therefore have with scarcely an exception adopted the generic names of the authorities we have mentioned, and also their family groups, occasionally, however, for the sake of uniformity changing the few terminations of the names of the latter into idæ where that had not been previously done, intending by such uniformity of termination to denote more readily the rank of the group in the system. The labour of clearing up the intricate synonyms that have crept into the science, is one of the greatest, and is certainly the most irksome, that the ichthyologist has to encounter, and one whose successful results are generally shown by the adoption of a single word, giving no indication to the uninitiated of the time, and research, and thought they have cost. It is, however, a labour that cannot be lightly passed by; for without a correct determination of the species the descriptions are useless or encumbering to science. Without such careful preliminary work no one can enter at all upon the subject of the geographical distribution of species. Yet that branch of ichthyology, no less than the habits of the species, is of vast importance to a maritime nation, desirous of extending her fisheries, and thereby increasing the supply of a most healthy and nourishing food for her teeming population, and raising new nurseries for seamen.

However desirous we may be of adding a few words on the geographical distribution of fish, the time has not yet arrived for enunciating many observed facts. There is as yet no general list of species comprising the whole class, and in local lists our conclusions are universally marred by the clashing of synonyms, and the superabundance of nominal species. A work, however, has been going on for some years, silently almost, and without attracting a tithe of the notice it deserves from scientific zoologists, but which, when completed, will supply exactly what is required. We mean the Zoological Catalogues of the British Museum, now in the course of publication in parts. The enlightened plan of this catalogue, as conceived by Dr John Gray, the keeper of the zoological department of the Museum, is to comprehend descriptions of all known species, of which specimens are to be found in any of the great European museums, with a comparison of the actual specimens in every instance in which that can be effected. In this way, not only are the species in the British Museum correctly named and pointed out, so as to relieve future inquirers of a load of labour; but the species not to be found in the Museum are also indicated. We know of no work on Natural History better planned, nor one that is likely to have ON THE GEOGRAPHICAL DISTRIBUTION OF SPECIES.

This is a wide field for observation and discussion; but the way for entering upon it with much hope of success has not as yet been cleared. Systematic Ichthyology is but of recent date; our acquaintance with the species of fish is as yet limited; our knowledge of their habits and migrations very imperfect; and we should only lead to error, were we to attempt to deduce general laws from such scanty data. We can merely therefore glance at a few circumstances connected with this department of Ichthyology, which, little as it has hitherto been considered, will, when the science has advanced to the proper point, certainly meet with the attention it so fully merits. Temperature has an acknowledged influence, both directly and indirectly, on the distribution of organized beings over the globe. Vegetation ceases, or nearly so, when we reach the regions of perpetual frost, either by ascending lofty mountains, or sailing towards the poles; and even the Protococcus nivalis, that propagates and flourishes in the snow, must owe its growth to the action of the sun's rays, in liquefying a portion of the snow sufficient to furnish fluid for the extension of the simple cells of which it consists. The range of phytophagous animals depends, of course, on that of the plants which they can eat and assimilate; and their distribution again influences that of the predacious kinds which subsist solely or mostly on animalized matter. Migration, though not synonymous with distribution, yet inasmuch as it is an instinctive movement, having for its end proper supplies of food, must furnish many facts that bear on the dissemination of species. The extent and character of the migration varies with the species. Among Mammals it has been little noticed, except in the gregarious Ruminants and certain Rodents. The American bison roams over the prairies in quest of fresh grass. When the herbage has gone to seed in one locality, and the haulms are dried up, the vast herds travel onwards till they find a younger and greener vegetation in some district over which a fire has recently run. This movement, whatever may be the extent of the journey over these sea-like prairies, scarcely comes under the term migration. But the reindeer, pressed by some more recondite instinct, quits the interior where it has fed in winter, and in herds of greater or smaller size, but in numberless succession, and all actuated by a common impulse, hastens to the coasts and islands of Hudson's Bay, or of the Arctic Sea, passing rapidly over the intervening barren districts wherein pasture is scanty; but throughout the march regularly waited upon by bands of wolves. Birds, with their greatly superior locomotive powers, perform migrations much more remarkable for the length of way. Vast numbers of Anatidae, natives of the extreme capes and islands of Arctic America, assemble in flocks on the approach of winter, and move southwards to pass that season on the table-lands of Mexico and of Central America, lingering on their way only in berry-producing or marshy districts and coasts, and passing over the others high in the air, and with great velocity. The annual migrations of the Swallows are no less extensive than those of the Natatores, and are as evidently designed to secure an appropriate succession of food. Every species has its proper range, that of some being of much greater extent both northwards and southwards than others. Of the Reptilian class, the alivorous Chelonians resort in numbers to certain solitary and sandy shores, for the purpose of depositing their eggs, but there is, as far as we know, no extensive migration of any member of that class in search of food. The Pinnotheres, a family of Crustaceans, also assemble annually in multitudes, descend from their usual places of abode in the interior, and travel in a straight line to the sea, to deposit their eggs in the sand of the shore. It is questionable whether any kind of fish makes long migrations either to seek for food or to deposit its eggs. Herrings have been said to do so, and to issue from their polar retreats to visit their proper spawning places on the coasts of Scotland; but as regards the length of their journey, this is probably a mistake, though there can be no doubt, that in common with many other fishes, they seek the shallow waters at spawning time; and it is true also, that the common Herring exists in the arctic seas, but it is precisely in the spawning months that it has been taken off the arctic shores of America, as well as in the British friths.

In respect of the power of making long journeys, many fishes are as favourably endowed as the swiftest bird,—their muscular powers are as great or greater, and the medium in which they move is more nearly equal to their bodies in gravity. Whoever has seen the Dolphin (Coryphaena) accompanying for days together a fast-sailing vessel running at speed before a fresh trade-wind, and occasionally shooting ahead, or playing round her as if she were at anchor, can have no doubts about the velocity with which a fish can travel. It has been calculated, indeed, that the Salmon can travel 20 miles an hour against the stream, and that the Tunny or Coryphaena would encircle the globe in a few weeks. This shows us, that unless the diffusion of a species be limited by other causes, mere distance is no obstacle to very many fishes. A bird in its migratory flight can soar high, and take advantage of the upper or lower currents of the air that may be favourable for its course, while at the same time it carries along with it the temperature of the colder regions it has left; the tenacity of the atmosphere being in fact the limit to its ascent. In the same way a northern fish might find at a distance from the surface the mean temperature of the sea (39°5 Fahr.), its descent into the bosom of the ocean being limited by the pressure it can bear. This line of mean temperature varies in its depth with the latitude. Sir James C. Ross found it to be, in S. Lat. 45 degrees, 3600 feet below the surface; and in the equatorial and tropical regions 13,000 feet, the surface heat being in the latter districts 78°. In 70 degrees of south latitude, the surface heat is 30° Fahr., and the mean heat of 39°5 has descended 4200 feet.

The obstacles that are likely to arise to a long journey by any fish, and also to the spread of the species, will vary with its habits. Ground fish, organized for swimming near the bottom only, and feeding there, will be stopped by great depths of the ocean as effectually as a land animal would be by a high mountain range rising far into the snowy regions,—they would neither be able to endure the pressure they would have to encounter at great depths, nor the privation of food to which they would be exposed in following the bottom to a depth to which they were not accustomed. James Forbes, whose early death has deprived Natural History of one of its most able and successful cultivators, has shown that marine life diminishes with the depth, and at length ceases, not perhaps at the limit he was inclined to assign to it, but still in a manner analogous to the ascent of a mountain. To favour the spread of ground-fish, then, a chain of sand banks, submerged to the proper depth, would be necessary. While the Scomberoides and other fishes that habitually swim near the surface would be more directly influenced by temperature, both as regulating the supplies of food, and as acting immediately on their own constitutions.

There can be no doubt that species have been framed to endure certain degrees of temperature only; that some which thrive in water, just above the point of congelation, would perish in the tepid ponds of intertropical regions, and vice versa. Dr Davy has shown that a continued heat of 80° will addle the egg, and destroy the embryo of the common Salmon; the fact of that species being limited to the countries lying northwards of the 41st parallel of latitude being most probably dependent on the small power the species has of resisting heat. On the other hand, the experiments of Broussonnet show that by using much caution, and elevating the temperature gradually, fish of temperate regions may be brought to endure a heat of 97° Fahr. The Ambassiss thermalis is reported in the Histoire des Poissons, on the authority of M. Renaud, as capable of inhabiting the hot springs of Cannes, near Trinquemalé, in a temperature of 115°-25 Fahr.; but there is reason to suspect some inaccuracy of observation here. Dr Davy visited these springs in 1817, when of seven wells, then existing, the hottest and principal one, and the one which he thought supplied the others, had a temperature of 105°-75 Fahr.; but the heat was said to vary, and he was told that it occasionally rose to 110°. The coolest of the seven wells had a heat only of 86° Fahr.; and in one only, whose temperature was 91°, did he see any fishes. Many small fishes, such as the Antennarii, and others of the less active swimmers, dwell in the floating islands of Sargasso, and most probably spawn among its stems. Though they find shelter in its mimic groves from the predacious birds and fishes, yet they must be exposed to a pretty high temperature under the direct rays of a tropical sun, against which, however, nature has furnished them with a protection, in the copious secretion of mucus which envelops their skins. The Anobas, again, ascends the palm trees of Bengal, and endures the heat of an atmosphere rising to 97° in the shade; while the Callichthys of tropical America must be exposed to at least an equal heat in its overland journeys. Fish constituted to brave such heats would speedily perish, there is every reason to believe, in colder regions; and a review of the whole class leads irresistibly to the conclusion that many species have been created solely to meet the conditions of existence which certain limited localities afford, such as the Amblyopsis of the Mammoth Cave of Kentucky, and the Siluroids of the mud volcanoes of the Andes.

The creation of a single pair of each species in certain spots, and the diffusion of their progeny from thence, has been of late a favourite subject of speculation; but this implies the subsequent calling into existence of the more predacious kinds, when the others had multiplied, so as to need a check; and the simpler supposition, and the one that is most consistent with the facts that are known, is that when the ocean was in a condition to support ichthyic life it was peopled by the Great Creator, each species being placed in sufficient numbers in the district best suited to its structure and habits, and the purpose it was designed to serve, while at the same time the balance between reproduction and supplies of food was provided for by a sufficient number of the rapacious kinds. And, moreover, that new species were created when a change in the condition of the ocean and its boundaries led to the extinction of the older races, and rendered such an exercise of creative power necessary.

Our limits will not permit us to stray into further speculation, and we shall conclude this article by hastily glancing at a few general facts. The northern seas, which are for the most part comparatively shallow, nourish many of the Geographical Distribution. Sclerogenidae, which feed at the bottom and frequent shelving, sandy shores or sandbanks. The majority of these have barbels or portions of the pectoral fins detached or otherwise organized as fingers or organs of touch. An allied group, the Uranoscopidae or Trachinidae, have often the tips of the anal rays similarly constituted. The Gadidae, also, which have barbels under the chin, are ground feeders; and these, with the Cotti and Scorpaenae among the Sclerogenids, and the fresh-water Trutta, and anadromous Salmones, are the most characteristic groups of fishes in the northern seas. The same generic forms of sea-fish, but not the same species, reappear in corresponding southern latitudes; the Cotti, Scorpaenae, and Gadidae being also conspicuous among the South Australian fishes. The Sclerogenids are not unknown in the middle tropical districts of the ocean, but they are different generically; the Cotti and Scorpaenae being replaced by Pelors, Synanceia, and others of a different aspect. There is a general resemblance between the fishes of the northern and southern extra-tropical seas, so that emigrants to Australia have very generally bestowed familiar European names on the sea-fish they found in the country of their adoption. In like manner there is a similarity of general aspect, but an almost total difference of species between the fish of Behring's Sea and the Sea of Ochotsk, and those of the German Ocean—though there are some facts which lead us to infer that in a higher parallel still there is a zone in which the same species form a circumpolar ichthyic fauna. This is different, both generically and specifically, from the fragments of the antarctic circumpolar groups of fish, which have reached us through Sir James Ross, the only navigator who has made collections in the high southern latitudes. Some genera, of few species, are the more remarkable from their occurrence both in the northern and southern seas, though in form of distinct yet closely resembling species. Macrourus has two representatives in the seas of Greenland and Norway; two in the Mediterranean; and two in the Australian seas. Lophius has one species in the European seas and another in the sea of China, so much alike that very close comparison is required to distinguish them. Zeus, also, and the allied genus of Capros, have each a species in the Mediterranean and temperate parts of the North Atlantic, as well as in the seas of Australia. The Greenland and Iceland Notacanthus, also, or Campylodon of Fabricius, reappears in the seas of South Australia with exactly the same generic aspect, but some subordinate difference of details, showing the species to be distinct, and without having been detected in the intervening districts of the ocean. No example of the genus, M. Valenciennes remarks, has ever reached the Paris Museum from the Indian Ocean. The true Salmonoidae or Trutta of some authors are confined, as we have already more than once remarked, to the northern hemisphere. They do not pass the great Himalayan range. We have seen none from Africa, nor a figure of any species among the drawings made at Canton of all the fish brought to that market, though the Salmonoidae are both various and plentiful in the Kamtschadale seas. The Characinidae, once included in the Salmon family, because they possess the characteristic Limanara mark, an adipose fin, are chiefly South American; while the Scoeliniidae, another family having also an adipose fin, are oceanic, being found in all seas from the German Ocean to the Chinese, Australian, and Polynesian waters, the only large district from which specimens have not hitherto been brought being the North Pacific and Behring's Sea. They are small fish, mostly nocturnal in their habits, and though many of them carry phosphorescent lamps, they have until lately escaped the observation of mariners; but when the practice of keeping a trawl overboard becomes more frequent, it is likely that they One large portion of the ocean, including the Sandwich Islands and the more southern Chinese seas, the Indian Ocean, Red Sea, and Polynesia, down to the northern and eastern coasts of Australia, forms an almost uniform ichthyic district, from the general diffusion throughout it of a great majority of the species that exist within its limits—though there are many local littoral species within its bounds. The Scomberoid skimmers of the surface are nearly the same in all parts of this wide sea. As we approach its confines, N. and S., there is a gradual intermingling of the forms belonging to the higher latitudes on each side; and on removing still farther from the equator, we find the seas of Kerguelen's Land, South Shetland, and Cape Horn showing as much identity of species as those of Norway, Spitzbergen, and Greenland; the Notothenia, however, and other predominant forms in the Antarctic seas being dissimilar to the Arctic ones. In fact, there is a greater generic dissimilarity between the extreme Arctic and Antarctic fish than we observe between the fish of the British Channel and the antipodal species. A Notothenia, we may add, is one of the most southern fish, having been found to the amount of 28 lbs. in the stomach of a seal, in S. Lat. 66°, on Sir James C. Ross's voyage; and an Ophidion was found by the same distinguished navigator to the N. of Spitzbergen. Both seek shelter from the seals in crevices of the ice.

With respect to fresh-water fish, the common Salmon, as we have more than once mentioned, is identical on both sides of the North Atlantic down to the 41st parallel, but does not occur in Behring's Sea; and we are not aware of any other species of Salmo or Trutta being common to the Old and New Worlds, although the family is even more abundant both in individual numbers and in variety of specific forms than in Europe or Asia. Sturgeons, another family of fresh-water fishes, containing anomalous members, have a less high northern range than the Salmon, not being found in rivers that fall into the Icy or Arctic American seas, but existing abundantly in most of the great rivers of Siberia and North America that flow southwards, or laterally, into the Black Sea, North Atlantic, or Northern Pacific. The genus exists in China, but we have seen none from the southern hemisphere. This leads us to observe, that no living Ganoid fish has as yet been detected in the southern hemisphere. The Pharyngobranchii are confined as natives to India and the Cape of Good Hope, though one or two species have been transported to Cayenne, and thrive there. Some of the remarkable genera that occur in the Nile exist also in the Gambia and Niger, though, as far as we know, not the same species; and there is a similar likeness between the marine fish of Western Africa and those of the Red Sea, extending in one or two instances even to species. The Siluroids have their headquarters in India and the southern seas, the species being comparatively few in Europe and North America. There are many in South America; and the Goniodonts are exclusively natives of that country.

There are other facts connected with this subject, some of which we shall simply mention without dwelling on, such as the influence of the Gulf Stream and other oceanic currents, in bringing fish that are natives of the warmer districts of the ocean into the higher latitudes. A drift tree or a spar is seldom met with at sea without its attendant fish, especially if it has been long enough afloat to be covered with fuci and barnacles. It would appear as if these fish stuck by it in all its wanderings, from their unwillingness to quit it, even when approached by a boat. And all mariners are familiar with the fact of certain fish following a ship for weeks together, until it has entered the colder latitudes. The beautiful Naucrates, or Pilot-fish, has in this way been brought to the Cornish shores, and we have known the Echeneis to attach itself in considerable numbers to a ship's bottom in the Bight of Benin, and to continue there until the Azores were passed on the homeward voyage. (J. R.—N.)

*The accomplished naturalist and excellent man, James Wilson, by whom the first edition of this article was penned in 1835, was preparing to revise his work when death put an end to all his labours, and the task which he would have accomplished so well was entrusted to another. During the last twenty years Ichthyology has gained so many new facts that it became necessary to write the whole over again; but such passages of the original treatise as were suitable have been interpolated in the text.

NOTE.—At page 205 we have mentioned the Molaena venenosa as being occasionally a poisonous fish; and at page 312 the Tetraodon are noticed as having generally a bad reputation on the same account. Not without reason, indeed, since the small liver of a single Tetraodon was the cause of two deaths at the Cape of Good Hope. The subject is one of much interest both to seafaring men and to physiologists; and we gladly avail ourselves of a little space here on this page to insert a few of the details given by Dr Julius Hellmuth, surgeon of the Dutch brig of war, and Mr Hugh Jamieson, surgeon of the royal navy, who witnessed the fatal occurrence.

"J. Kleinhaus, boatswain's mate, thirty-two years of age, and J. Hansen, purser's steward, forty-three years of age, had partaken at dinner-time (noon), in addition to the usual ship's fare, of the liver of a fish. Within ten minutes he was called to render assistance to both, and observed the following symptoms—J. Kleinhaus could not raise himself without the greatest exertion, his face was somewhat flushed, his eyes glistening, and pupils rather contracted; the mouth was open, the muscles of the pharynx spasmodically contracted; the lips tumid and somewhat blue; the forehead covered with perspiration, and the pulse quick, small, and irregular. The patient was in great distress but still conscious. He complained, but with great difficulty, of pain from constriction of the fauces and gullet, together with great uneasiness in the region of the stomach, and had an inclination to vomit. An emetic was administered, but he could scarcely swallow it, and he almost immediately became paralytic; his eyes were fixed in one direction, his lips became livid, and his pulse failing; he expired in about seventeen minutes after eating of the liver of the fish. There was no full vomiting during the rapid action of the poison, the emetic having produced no effect. The other patient vomited thrice, the first time before taking an emetic which was given to him, followed by copious and warm water, which caused a repetition of the vomiting, after which he said that he was easier, but in a few moments a single convulsive movement of the arms ensued, the livid tongue was protruded from the mouth, and he expired about one minute later than his comrade. Mr Jamieson did not reach the Dutch vessel till forty-five minutes after twelve, before which time both men had expired. He found their faces collapsed, the skin covered with cold moisture, the lips livid, pupils of the eyes moderately dilated, the joints still flexible, and the limbs relaxed. On examining the bodies next day the stomachs were observed to be moderately distended with pulmaceous food, nearly wholly reduced to the state of chyme, none of which had passed the pylorus. None of the poisonous fish could be distinguished among this comminuted mass. The inside of the stomach round the cardiac orifice was of a deep purple colour, and minute ramifications of the vessels extended along the smaller arch, and to the circumference at the beginning of the greater arch. The vascularity was not perhaps greater than it would have been in a healthy stomach during the first stage of digestion; but it was rendered more conspicuous by the dark colour of the blood. In the right ventricle of the heart there was a fibrinous clot and a small quantity of fluid blood; the left ventricle was moderately distended with dark fluid blood; the muscular tissue of the heart was natural, and the muscles of the body generally were florid and healthy in appearance. The spotted Tetraodon measured from 6 to 8 inches, and it was the liver only, not exceeding 4 drams in weight, that was eaten by the men." FOSSIL ICHTHYOLOGY.

Or all the vertebrated animal creation fishes are by far the most numerous species, and are the most widely distributed in the strata composing the crust of our earth. Some are found in formations as old as the Silurian, and become very numerous in all the more recent formations, even to the Tertiaries containing the remains of mammals. Fossil fishes, therefore, possess a high geological interest; and aid us greatly in determining the successive changes which have affected the surface of our planet.

Our knowledge of Fossil Fishes was, until very lately, exceedingly imperfect. Indeed, with the exception of the Ittilithologia Veronese, published in 1796, we had scarcely a tolerable attempt at the determination of fossil species, before the appearance of the magnificent and truly scientific Recherches sur les Poissons Fossiles of M. Agassiz (1833-43). In the first-mentioned work, however, fossil species are often confounded with fishes now existing; although not a single species of the immense accumulation in Monte Bolca, though evidently belonging to a comparatively recent geological epoch, is identical with any fish now existing. Good descriptions, it is true, of some fossil fishes were scattered through various works; but they were connected by no general classification to unite them into allied groups, or to exhibit their relations to the various geological series of formations that compose the crust of our earth. But the work of Agassiz was a gigantic undertaking; and the success which has crowned his labours is most creditable to the unwearied industry and great talents of this distinguished naturalist. He has presented his readers with full descriptions or notices of about 1000 species of fossil fishes, illustrated by accurate and exquisite designs, and supplied us with a method of determining the species that may be hereafter discovered, with a certainty and precision that has no parallel in this branch of natural history. This is the result of the examination of more than 20,000 specimens of fossil fishes preserved in the public and private museums of Europe; and now that he has taken up his abode in North America, we know that he pursues this subject with his accustomed energy, and will no doubt add greatly to our knowledge of this subject, one of the most interesting branches of geological palaeontology.

In his work on the Fresh Water Fishes of Europe, M. Agassiz had pointed out the important character to be obtained from observing the form and structure of the scales of fishes; and this character he successfully employs as the distinction of the four orders into which he divides the class of fossil fishes. He had before pointed out the constancy of the structure of the scales in each kind of fish; a character which had been too much overlooked by preceding naturalists, although this integument is a principal medium by which external influences reach the internal organization of the animal. He considers it as a sort of external skeleton, differing widely and invariably in its structure, in each of the great divisions of this class of animals. The scales have, too, a peculiar value in fossil ichthyology, from the perfect manner in which their durable nature has preserved their minutest features in their stony repositories. Thus, the examination of a few scales determines the order to which the specimen should be referred, and often points out their affinities to existing species.

The orders are divided into Families, chiefly from the structure and position of the fins, from the form of the bones of the head, especially of the teeth, and the structure of the opercula or gill covers; and a most important character is obtained, especially in the Placoid order, from the spinous rays of the several fins, which often are the formidable defensive weapons of the fish.

In these researches, M. Agassiz has freely acknowledged the assistance he has received from contemporary naturalists, and speaks in high terms of the valuable labours of Blainville, Eichwald, Buckland, Sedgwick, Murchison, Miller, Hibbert, and especially of Richard Owen, whose most valuable Odontography has thrown so much light on zoological subjects.

In the following sketch of this new and interesting subject we shall endeavour to present, as far as the necessary limits of the work will permit, a general view of the system of Agassiz.

M. Agassiz divides fossil fishes, as he had previously done their living representatives, into four great orders—the Ganoid, Placoid, Ctenoid, and Cycloid—founded on the form of their scales. This arrangement would comprehend the immense variety of existing fishes, except two genera, Myxine and Petromyzon, which are totally destitute of scales.

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I.—Ganoid fishes (figs. 1, 2, 3), (so designated from γανός, splendour) have shining scales, covered with a firm enamel, generally of a rhomboidal form, and imbricated, or applied to each other as the slates on a roof. II.—Placoids (figs. 4, 5), (from πλάκη, a table) have scales not imbricated, but approximate on the skin; they are often elevated in the middle, and sometimes have a strong projecting point or spine from their centre. The Placoids embrace the genera referrible to the families of the shark and ray of Linnæus.

III.—Ctenoids (figs. 6, 7, 8), (from κτένις, a comb) have imbricated scales, generally of a rounded or ovoid form, with several teeth or sharp projections on their posterior margin.

IV.—Cycloïds (figs. 9, 10, 11, 12), (from κύκλος, a circle) have circular imbricated scales, without dentations on their margins, but with concentric markings. Three-fourths of all known fossil fishes belong to the two last orders, and occur in all formations from the chalk upwards. The fishes found in the older rocks are the least numerous, and belong chiefly to the first order; the Placoids extend through all the fossiliferous rock-formations, but are chiefly found in the coal, Jurassic, chalk, and tertiary formations; while not one species of Ctenoid or Cycloid fish occurs in formations older than the chalk. Fishes belonging to the older formations differ most from existing species in form and structure; and Agassiz states that the fishes of the older geological formations have smaller pectoral fins (the representatives of the fore extremities of the higher classes of animals), and that they are invariably placed before the ventral fins; so that they belong to the Linnæan order of Abdominates. In the formations above the chalk, the ventral fins approach nearer to the head; while in those below the chalk, the ventral fins are always behind the pectorals.

M. Agassiz divides the orders of fossil fishes into families, genera, and species, the characters of which are chiefly derived from the structure of the bones of their spine, head, opercula, teeth, and the form of their bodies and position of their fins. It may suffice to state that the fins placed perpendicular to the plane of the body are, according to position, denominated the Dorsal, the Ventral, the Anal, and the Caudal or fin of the tail. The Pectorals are always a pair of fins, one of which is on each side of the thorax of the fish; and according as the ventral fin is situated behind, under, or before the pectoral the fish said to be abdominal, thoracic, or jugular. When the ventral is wanting, they are said to be apodol. The bones, the scales, and the fins being those parts generally best preserved in fossil fishes, they are chiefly relied on by M. Agassiz, whose intimate knowledge of living species has enabled him, like another Cuvier, often from a few fragments, to determine the genus, or even the species, to which the scattered relics have belonged.

ORDER I.—GANOÏDEI.

Scales angular, rhomboidal or polygonal, formed of osseous plates, covered by enamel.

FAMILY I.—LEPIDOSTEI.

Teeth scopular or brush-like, disposed in several rows, consisting of a single row of small obtuse teeth. Scales flat, rhomboidal, parallel to the body, which they wholly cover. All the genera of this family that have the bones of the back produced into the upper lobe of the tail, or are what Agassiz terms heterocerques, occur in strata earlier than the Jurassic. Those with the regular tail, or the homocerques, belong to later formations. This family has no representatives among existing fishes.

We shall shortly indicate the rock formations in which each fish occurs in the tables at the end of this article. FOSSIL ICHTHYOLOGY.

A. Body fusiform.

GENUS I. ACANTHODES. Teeth scupular. Scales extremely small; dorsal fin opposite to anal; no ventral; pectorals large; first ray of dorsal, anal, and pectorals thick, strong, and rough; the succeeding rays, as well as those of the caudal, very slender, and scarcely distinct. Lower jaw longer than the upper; mouth very wide. The known species are—

1. A. Bronnii. 2. A. sulcatus. 3. A. pusillus.

GENUS II. CATOPTERUS, &c. DIPTERUS. This is Dipterus of Sedgwick and Murchison. Dorsal long, opposite to anal, and both extending nearly to caudal; dorsal seemingly consists of two portions; ventral uncertain; pectorals small. Scales of middle size.

1. C. macrolepidotus. 2. C. gracilis. 3. C. parvulus. 4. C. anguilliformis.

GENUS III. AMBLYPTERUS. All the fins very large, composed of numerous rays, especially the pectorals; dorsal opposite to the space between the ventral and anal; no small rays at the margin of the fins, except in the upper lobe of the caudal. Scales of middle size.

1. A. macropterus. 2. A. eupterygius. 3. A. lateralis. 4. A. latus. 5. A. nemopterus. 6. A. punctatus. 7. A. striatus. 8. A. Agassizii. 9. A. Eifelensis.

GENUS IV. PALEONISCUS. All the fins of middle size, with small rays at their margins; dorsal opposite to space between ventral and anal. Scales of middle size—there is always a large scale before the first ray of the dorsal and anal fins.

1. P. faltus. 2. P. Duvernoy. 3. P. minutus. 4. P. angustus. 5. P. Blainvillei. 6. P. Volzii. 7. P. macropomus. 8. P. Freieslebeni. 9. P. magnus. 10. P. elegans. 11. P. Vratislavensis. 12. P. lepidotus. 13. P. Rostovensis. 14. P. striolatus. 15. P. ornatissimus. 16. P. comptus. 17. P. gaphryus. 18. P. microphthalminus. 19. P. longissimus. 20. P. carinatus. 21. P. Agassizii. 22. P. macropterus. 23. P. Egertonii. 24. P. Monensis.

GENUS V. OSTEOLEPIS. Two dorsal fins, the first in the middle of the back, the second in the middle of the space between the first and the tail, while the two analts alternate with the two dorsals, and the second anal extends behind the second dorsal; the pectorals are large and rounded; the ventral small, and opposite to the anterior edge of the first dorsal. Scales larger than paleoniscus. Mouth large, armed with small teeth.

1. O. macrolepidotus. 2. O. microlepidotus. 3. O. arenatus. 4. O. major.

GENUS VI. CHEIRACANTHUS. Body covered with small scales. Pectorals, dorsal, ventral, and anal fins, with a strong spinous ray; dorsal in the middle of the back, opposite to the space between the ventral and anal. Jaws armed with several rows of very small pointed teeth.

1. Ch. Marchioni. 2. Ch. microlipodotus. 3. Ch. minor.

GENUS VII. CHEILOEPIUS. Body covered with very minute scales. Fins without the bony ray, but its place supplied by slender rays laid on each other in an imbricated manner. Mouth large; teeth small. Dorsal placed posteriorly to the anal.

1. Ch. Trailli. 2. Ch. uragus. 3. Ch. Cummingia.

GENUS VIII. DIPLAGANTHUS. Body cylindric; tail short and heterocercous. Scales very minute. Two dorsal fins; the first near the head, a little before the pectorals; the second opposite to the anal; pectorals placed on a strong thoracic belt, on which are some spines; the anal has a strong osseous ray, and similar rays are in the other fins, except the caudal.

1. D. striatus. 2. D. striolatus. 3. D. crassispinus. 4. D. longispinus.

GENUS IX. COCCOLEPIS. Body small, covered by uniform minute scales, which are finely granular. Dorsal fin proportionally very large, and truncated behind, so as to form an equilateral triangle; ventrals small, and approximated to the anal, which is larger than the ventrals. The Ganoidel only genus known is—

1. C. Backlandi.

GENUS X. PLECTOLEPIS. Not described by Agassiz. The scales are somewhat rounded and pointed, giving a rough appearance to the skin of the fish.

1. P. rugosus.

B. Body Flattened.

GENUS XI. PLATYCEPHALUS. Body very broad, or much elevated, almost trapezoidal, and nearly as high as long, covered with large scales. Mouth small, with scupular teeth. Dorsal and anal opposite to each other, and extending from the middle of the body to the root of the tail, with their anterior rays the longest.

1. P. gibbosus. 2. P. rhombus. 3. P. striatus. 4. P. macrus. 5. P. parvus.

GENUS XII. GYROLEPIS. Chiefly distinguished by the scales, which have striae or ridges running concentric or parallel with the edges of the scale; sometimes they are oblique, or irregularly ramified.

1. G. maximus. 2. G. tenuistratus. 3. G. Rankini. 4. G. Alberti.

GENUS XIII. EURYNOTUS. Dorsal large, occupying the length of the back, with the anterior rays much elongated; anal opposite to the posterior part of the dorsal, with its anterior ray longer than the rest; ventral large, placed in the middle of the abdomen; pectorals still larger, with their tips reaching to the insertion of the ventrals; caudal less developed than the other fins. Head large; mouth with very small obtuse teeth.

1. Eu. cretaceus. 2. Eu. fimbriatus. 3. Eu. tenaiceps.

GENUS XIV. DAPEDIUS. Body broad, and rapidly decreasing to the root of the tail, which is thick. Head rounded. Teeth sloping on their cutting edges. Fins of middle size; the caudal is the largest; the dorsal extends from the middle of the back to the root of the tail.

1. D. politus. 2. D. granulatus. 3. D. punctatus. 4. D. Colei. 5. D. orbis. 6. D. micans. 7. D. attilves. 8. D. arenatus.

GENUS XV. TETRAGONOLEPIS. Resembles the last in most respects, but has pointed teeth, instead of the sloping teeth of Dapadius.

1. T. semicinctus. 2. T. confusus. 3. T. speciosus. 4. T. radiatus. 5. T. punctatus. 6. T. leiosomus. 7. T. Leachii. 8. T. macdonaldii. 9. T. pholidotus. 10. T. ovalis. 11. T. Bonel. 12. T. dorsalis. 13. T. monilifer. 14. T. angulifer. 15. T. Magneville. 16. T. mastodoncus. 17. T. striolatus.

GENUS XVI. AMBLYURUS. Body broad, flattened. A long dorsal commencing opposite to the ventral; a small, straight anal; and a wide, truncated caudal. Mouth wide; jaw narrow, armed with small pointed teeth.

1. A. macrostomus.

C. Body Elongated.

GENUS XVII. SEMIONOTUS. Body generally of large size. Head elongated; jaws narrow, with scupular teeth more or less minute. Dorsal long, commencing opposite the ventrals, and ending over the anal; pectorals of mean size; ventrals wide; anal narrow, with its first ray longer than the rest; caudal forked, with the upper lobe a little longer than the lower, though the vertebrae do not really extend into the upper one, as hasty inspection might suppose.

1. S. leptcephalus. 2. S. Bergyl. 3. S. latus. 4. S. minutus. 5. S. Nilssonii. 6. S. Pentlandi. 7. S. striatus. 8. S. rhombifer. 9. S. pustulifer.

GENUS XVIII. LEPIDOTUS. Body the form of a large Carp. Greatest thickness of the body just behind the thoracic belt; scales large, rhomboidal. Fins of middle size; dorsal over the space between the ventral and anal; caudal almost square; anal shaped like the dorsal; and FOSSIL ICHTHYOLOGY.

Genus XIX. Pholidophorus. Resembles the Herring, but with enamelled rhomboidal scales. Fins as in Lepidotus; caudal deeply cleft, with equal lobes. Jaws with small scopular teeth.

1. Ph. Bechti. 2. Ph. omychius. 3. Ph. macrocephalus. 4. Ph. microps. 5. Ph. bentheimeri. 6. Ph. longiseratus. 7. Ph. striolarius. 8. Ph. latissimus. 9. Ph. bicoloricus. 10. Ph. intermedius. 11. Ph. latissimus. 12. Ph. ornatus. 13. Ph. fleischeri. 14. Ph. limbatus. 15. Ph. strictlandii. 16. Ph. hastatus. 17. Ph. angustus. 18. Ph. gracilis. 19. Ph. minor. 20. Ph. furcatus. 21. Ph. dorsalis. 22. Ph. latissimus. 23. Ph. pullarius. 24. Ph. taxias. 25. Ph. radians. 26. Ph. uranoscopus. 27. Ph. radiopunctatus. 28. Ph. maximus. 29. Ph. pachysomus. 30. Ph. creminatus. 31. Ph. Hartmanni. 32. Ph. fusiformis. 33. Ph. leptcephalus.

Genus XX. Nothosomus. Scales broader than long. Dorsal fins very long. Size small. Like the last genus, except in having two dorsal fins.

1. N. octostichus. 2. N. invisimus.

Genus XXI. Orthopsis. Elongated body, covered with equal scales. Superior lobe of the tail extends a little obliquely, and the fin forked slightly; pectoral very large and long; dorsal very long, but not deep; with the ventral opposite to its middle. Head small; but opercula broad and strong.

1. O. procerus. 2. O. pennellata. 3. O. dorsalis. 4. O. Mansteri.

Genus XXII. Notagogus. Resembles Pholidophorus, but is of small size, and with two dorsal fins.

1. N. Zeitenii. 2. N. Pentlandi. 3. N. latior. 4. N. denticulatus.

Genus XXIII. Propterus. Size small. Two dorsals, with the anterior rays of the first elongated beyond the rays of the second. Vertebrae are thick and short, with the interapophysial bonelets stout. Scales rhomboidal, and finely notched on their posterior margin; anal a little behind the second dorsal; and the ventrals opposite to the extremity of the first; caudal slender.

1. P. microstomus. 2. P. serratus.

Family II.—SAUROIDEI.

Pointed conical teeth, alternating with small scopular teeth. Skeleton osseous. Scales flat, rhomboidal, and completely investing the body.

In some of the genera, the vertebral column is continued into the upper lobe of the tail, a structure which Agassiz designates heterocercous; other genera have the tail in the regular form, which he distinguishes as homocercous. The heterocercous have all lived prior to the deposition of the Jurassic formation; the homocercous have existed at later geological periods. This family has no living representatives, except in the genera Lepidosteus and Polypterus.

A. Heterocercous.

Genus I. Pygopterus. Fins extremely developed; dorsal opposite to the space between ventrals and anal; anal much elongated; small rays placed on the anterior fin-rays.

1. P. Humboldti. 2. P. mandibularis. 3. P. Bucklandi. 4. P. Jamesoni. 5. P. Bonnardi. 6. P. Greenockii. 7. P. lucius. 8. P. sculptus.

Genus II. Acrolepis. This genus resembles the last; but the anal is short and in the centre of the space between the ventrals and the caudal fin; and the dorsal less extended than in Pygopterus; ventrals nearer to the anal than to the pectorals; caudal lobes unequal. Head thick and short; muzzle pointed; jaws armed with strong, conical, closely-set teeth. Each scale surmounted by one or more keels.

1. A. aculeatioris. 2. A. asper. 3. A. Sedgewickii.

Genus III. Sauroichthys. This genus only known by fragments of its jaws and teeth. Teeth, short, conical, slightly compressed at the sides, with the bone supporting the enamelled point finely longitudinally striated, the point smooth. They have much resemblance to the teeth of land lizards. The fishes seem to have been of small size.

1. S. apicalis. 2. S. Mangeedi. 3. S. assimilis. 4. S. homalides. 5. S. semicostatus. 6. S. tenulirostris. 7. S. augustus. 8. S. costatus.

Genus IV. Diplopterus. Size large; body elongated, and tapering gradually to the tail. Head large, broad, and flat; muzzle rounded; eyes large, close together, and surrounded with strong scales; jaws strong, with a single row of closely-set teeth. Two dorsals opposite to two nearly similar anal fins; two large rounded pectorals placed on the sides of the throat. Tail heterocercous, with most of the rays inserted under the elongation of the vertebral column; caudal fin truncated almost vertically. The branchiostegous rays are represented by plates below the neck. Scales on the body rhomboidal and granular.

1. D. macrolepidotus. 2. D. affinis. 3. D. borealis or Agassizii. 4. D. carbonarius. 5. D. Robertsoni.

Genus V. Megalichthys. Size large. Scales rhomboidal, and finely granular; as are the opercula and plates on the head. The teeth have a furrowed root, and smooth point; and several large appear among many smaller teeth.

1. M. Hibberti. 2. M. maxillaris. 3. M. priscus.

Genus VI. Glaeptolepis. Imperfectly known. The scales are finely sculptured. Jaws supposed to be elongated from the fragments found.

1. G. ornatus.

Genus VII. Orognathus. Known only by fragments of the jaws which seem to have been straight.

1. O. conoides.

Genus VIII. Pododus. Known only by the form of its teeth. The only known species was found in the coal measures at Carlisle, in Lanarkshire.

1. P. capitatus.

B. Homocercous.

Genus IX. Ptycholepis. Scales with deep furrows, distinguished with difficulty from the divisions of the scales, which give them an irregular figure, and make the body appear rough. Head short, with large conical teeth. Tail slender, and the caudal rays small, which distinguish this genus from Eurypterus.

1. P. Bollensis.

Genus X. Sauropus. Vertebrae very short, with the slender apophyses almost in contact, with small interapophysial bones, and slender ribs, which are longer and less curved than the apophyses. Scales minute, rhomboidal. Pectorals large, so as almost to touch the ventrals; caudal equilobed, dilated, and deeply forked. Head short and thick; jaws with sharp, conical, rather distant teeth.

1. S. latissimus. 2. S. longissimus. 3. S. mordax.

Genus XI. Pachycormus. Body inflated, covered by very small scales. Caudal fin very broad, with many undivided rays, which, gradually lengthening towards the middle, give it a rounded form; dorsal in the middle of the back, opposite to the space between the ventral and anal; pectorals very large. Vertebrae very short. Branchiostegous rays numerous, and close-set.

1. P. macropterus. 2. P. curta. 3. P. macrurus. 4. P. he... FOSSIL ICHTHYOLOGY.

Genus XII. Thrissops. Resembles Sauropris, but has larger vertebrae. Pectorals large, straight, composed of a few large rays; ventrals small; anal very large, often extending to the root of the tail, and often equalling one-half the length of the body; lobes of the caudal unequal; all the fin-rays jointed and dichotomous. Head short and thick; jaws slender, with small sharp teeth.

1. T. formosus. 2. T. cephalus. 3. T. micropodus. 4. T. intermedius. 5. T. salmoneus. 6. T. subovatus. 7. T. mesogaster.

Genus XIII. Caturus. A large dorsal opposite to the ventrals; pectorals large; caudal forked. Head large; jaws very large, with large conical teeth interspersed among scapular teeth. Spinous apophyses of the caudal vertebrae strong, inclined, with their bodies approximate.

1. C. feroxatus. 2. C. latus. 3. C. similis. 4. C. pachyurus. 5. C. ferreus. 6. C. maximus. 7. C. angustus. 8. C. microcheirus. 9. C. branchiostegus. 10. C. elongatus. 11. C. macrodus. 12. C. Meyeri. 13. C. pleodus. 14. C. Bucklandi.

Genus XIV. Leptolepis. Scales very thin. Dorsal opposite to ventral; caudal forked. Mouth wide; teeth scapular in front of the jaw, and larger behind.

1. L. sprattiformis. 2. L. Valithii. 3. L. crassus. 4. L. macrolepidotes. 5. L. polypondylus. 6. L. Bronnii. 7. L. canalis. 8. L. Jageri. 9. L. leporus. 10. L. Knorrli. 11. L. dubius. 12. L. contractus. 13. L. filipensis. 14. L. paucispondylus. 15. L. pastilus. 16. L. tenellus. 17. L. macropthalmus. 18. L. latus.

Genus XV. Megalurus. Caudal fin rounded, very large, with slender, long rays; dorsal opposite to the space between the ventral and anal. Head large; jaws with large conical teeth, intermingled with smaller teeth.

1. M. lepidotes. 2. M. brevirostratus. 3. M. elongatus. 4. M. parvus.

Genus XVI. Egnathus. Fins generally large; dorsal deep and long, with strong rays, opposite to the space between ventrals and anal; anal smaller; all have their principal rays furnished with fulcra to their extremities; caudal has its upper lobe larger than the lower. Scales rhomboidal, large, but smaller on the belly, with grooves and dentations on their posterior margin, which fit into the contiguous margin of the next scale. Teeth unequal; very large, conical teeth being mingled with smaller, especially in the middle of the jaw.

1. Eu. orthostomus. 2. Eu. speleus. 3. Eu. Philopseus. 4. Eu. chirotes. 5. Eu. minor. 6. Eu. polyodon. 7. Eu. opercularis. 8. Eu. microlepidotes. 9. Eu. giganteus. 10. Eu. tenidens. 11. Eu. jactulatus. 12. Eu. ornatus. 13. Eu. scabrioculus. 14. Eu. lepidotus. 15. Eu. mandibularis.

Genus XVII. Conodus. Differs from Egnathus only in its dentation; as its teeth are all conical, and much more equal in size.

1. C. ferreus.

Genus XVIII. Amblysemius. Resembles Caturus, but its form is more slender, and its vertebrae less massive; the spinous processes more slender, and the end of the vertebral column is much elevated. Caudal forked; dorsal the largest fin.

1. A. gracilis.

Genus XIX. Thrissognathus. A genus intermediate between Thrissops and Sauropris, with a general resemblance to Pachyceirus; but its dorsal fin is in the middle of the back, with its anal elongated like Thrissops.

1. T. Colei.

Genus XX. Macrosemius. Size small. Dorsal extends along the whole back, with very large rays; caudal rounded, its upper lobe is less powerful than the lower; ventrals and anal small. Head thick; mouth small, but teeth strong and conical.

1. M. rostratus. 2. M. brevirostris.

Genus XXI. Saurostomus. Lower jaw elongated, and has a long row of large triangular teeth, compressed, with cutting edges. Muzzle elongated; size large.

1. S. esocinus.

Genus XXII. Aspidorhynchus. Body much elongated, upper jaw prolonged into a beak, extending beyond the lower, and with teeth in this projection; the upper jaw receives the teeth of the lower jaw in a groove. Dorsal fin placed far back, opposite the anal; pectorals and ventral rounded; caudal forked. Scales large, higher than long, especially on the middle of the body.

1. A. acutirostris. 2. A. speciosus. 3. A. ornatus. 4. A. mandibularis. 5. A. lepturus. 6. A. Anglicus. 7. A. eudus. 8. A. Walchensi. 9. A. Comptoni.

Genus XXIII. Belonostomus. Differs from Aspidorhynchus, which it much resembles, in having the jaws of equal length, or nearly so, and in having no groove in the upper jaw, while the body is more slender. Mouth deeply cut, with sharp, unequal teeth. Eye large. Skeleton robust.

1. B. spikyromeloides. 2. B. Munsteri. 3. B. acutus. 4. B. cinctus. 5. B. Amningia. 6. B. tenimirostris. 7. B. subalatus. 8. B. Kochii. 9. B. ventralis. 10. B. leptosternus. 11. B. brachysomus.

Family III.—Cetacanthi.

One of the most remarkable characters of this family is, that all the rays of the fins, and their bones, are hollow—a trait which occurs not in any other ganoid fishes. Another peculiarity is, that the rays are all stiff; articulated only at their bases, and are supported on the interapophysal bonelets, which takes place in other fishes only with the rays of the caudal and anal fins.

Genus I. Cetacanthus. There are two dorsals; the first is opposite to the extremity of the pectorals, the second to the space between the ventrals and the anal, which last approximates to the caudal; and the caudal comprehends the cluster of jointed rays that garnish the end of the vertebral column, and equals the one-third of the length of the fish. The scales large, elongated, with their posterior margin rounded. Teeth sharp and conical.

1. C. granulosus. 2. C. Phillippii. 3. C. minor. 4. C. gracilis. 5. C. lepturus. 6. C. Mansteri.

Genus II. Undina. Approximates the last in the fins; but the teeth resemble a pavement, as in some pycnodonts.

1. U. Kohleri. 2. U. striolaris.

Genus III. Holoptichthys. Size large; scales large and rugose. Bones of the cranium sculptured like those of the crocodile. The conical teeth exceed those of the largest saurians.

1. H. Hilberti. 2. H. sauroides. 3. H. falcatus. 4. H. Portlockii. 5. H. Garneli. 6. H. granulatus. 7. H. striatus. 8. H. minor. 9. H. giganteus. 10. H. Flemingsi. 11. H. nobilissimus. 12. H. Andersoni. 13. H. Marchesi. 14. H. Osmalusi.

Genus IV. Holopticus. Size small. Tail rather trilobate than forked, the terminal and principal lobe being between two other lobes, which last might be mistaken for a dorsal and an anal fin, were these not distinctly visible a little before these side lobes, which have another peculiarity in possessing a large spinous ray before their slender rays. Head very broad. The scales large.

1. H. Binneyi.

Genus V. Glyptosteus, v. Bothriolepis. The scales sculptured with grooves of various contorted forms, sometimes presenting isolated hollows, separated by rounded ridges, somewhat resembling the ripple marks on the seashore.

1. G. favosus. 2. G. reticulatus. 3. G. ornatus.

Genus VI. Glyptolepis. Body of middle size, as broad as deep. Scales thin, rounded, much imbricated, covered by a thin, smooth enamel, with fine radiating striae on their interior. Fins large; two dorsals opposite to two anal, approximate to the caudal, ventrals have thin rays supported on a series of plates extending along the belly, as in FOSSIL ICHTHYOLOGY.

Genus I. Placodus. Teeth of two kinds, viz., grinders, with flat crowns paving the interior of the mouth; the Pycnodontel largest occupy the middle of the dental-plate, with sometimes lateral rows; the incisors, or prehensiles are most massive teeth, and are less pointed than in other genera; and those of the upper jaw are implanted in a sort of beak. The anterior prehensile teeth are arranged in two rows, with six in each row.

1. P. gigas. 2. P. Andriani. 3. P. Munsteri. 4. P. rostratus. 5. P. impressus.

Genus II. Spheroodus. The teeth are only parts known, and are always rounded, often hemispheric, from the size of a pin's head to that of a lentil; the crown smooth, and covering the root.

1. Sp. gigas. 2. Sp. annularis. 3. Sp. cinetus. 4. Sp. conicus. 5. Sp. ovatus. 6. Sp. depressus. 7. Sp. discus. 8. Sp. latus. 9. Sp. irregularis. 10. Sp. microdon. 11. Sp. parvus. 12. Sp. mitralis. 13. Sp. Neocomensis. 14. Sp. oculus-serpentis. 15. Sp. truncatus. 16. Sp. minor. 17. Sp. minimus.

Genus III. Pycnodus. Body anteriorly truncated and puffed out, posteriorly elongated. Tail slightly sloping. Vertebrae massive, short; most species have remarkable bony pieces behind the nape that obliquely cross the spinous apophyses. Teeth smooth, with crown slightly expanded, surfaces more or less convex; middle or principal row of oval teeth transverse, bounded on each side by a double alternate row of smaller circular teeth.

1. P. platesus. 2. P. rhombus. 3. P. orbicularis. 4. P. gigas. 5. P. Nicolleti. 6. P. Bucklandi. 7. P. didymus. 8. P. rugosus. 9. P. umbonatus. 10. P. ovalis. 11. P. Hagli. 12. P. tollapicus. 13. P. Mantelli. 14. P. Munsteri. 15. P. complanatus. 16. P. subchavatus. 17. P. cretaceus. 18. P. latirostris. 19. P. obtusus. 20. P. parvus. 21. P. biserialis. 22. P. discoides. 23. P. angustus. 24. P. elongatus. 25. P. latior. 26. P. depressus. 27. P. marginalis. 28. P. trigonus. 29. P. latidens. 30. P. pricens. 31. P. gracilis. 32. P. minutus. 33. P. minor. 34. P. tristychus.

Genus IV. Gyroodus. Teeth elliptical or circular, with the summit provided with an umbilicated centre, surrounded by a circular turrow that divides it into two distinct parts. The superior jaw, the maxillaries, and intermaxillaries, have a single row of teeth; the vomer has five longitudinal rows, diminishing in size from behind forward; the lower jaw has four rows on each side.

1. G. macrophthalmus. 2. G. frontatus. 3. G. rugosus. 4. G. umbilicus. 5. G. Jurassicus. 6. G. Cuvieri. 7. G. punctatus. 8. G. trigonus. 9. G. radiatus. 10. G. levis. 11. G. cretaceus. 12. G. Mantelli. 13. G. minor. 14. G. augustus. 15. G. regulosus. 16. G. Munsteri. 17. G. runcinatus. 18. G. analis. 19. G. circularis. 20. G. platyrus. 21. G. punctatissimus. 22. G. rhomboidalis. 23. G. macropterus. 24. G. mammillaris. 25. G. gibbosus. 26. G. perlatus. 27. G. gracilis.

Genus V. Microdon. The form of the body is nearly that of Pycnodus. Dorsal and anal very long, opposite to each other, and prolonged to the caudal, which is much sloped and forked; pectorals small, with fine rays. The best character is taken from the teeth, which are smaller than in Pycnodus; they are in five rows on the vomer, and one row on each of the superior maxillaries; in the lower jaw there are four rows on each side of nearly equal size; they have a flattened angular form.

1. M. elegans. 2. M. hexagona. 3. M. analis. 4. M. radiatus. 5. M. platyrus. 6. M. abdominalis.

Genus VI. Globulodus. Teeth small, and pediculated at the summit, which distinguishes them from all the Pycnodonts.

1. G. elegans.

Genus VII. Colobodus. The teeth, disposed in irregular pavements, have their layers very serried, of a size between that of Microdon and Spheroodus, have a rounded or cylindric base, with their crown bent in the form of a club, having in its centre a little truncated papilla; all the surface of the teeth finely vertically striated.

1. C. Hogardi. GENUS VIII. SCROBODUS. Body fusiform, which is peculiar to this genus of all the Pycnodonts. The teeth marked with a distinct furrow.

1. S. jabovatus.

GENUS IX. PISODUS. Distinguished by Professor Owen. Crown of the very dense teeth fusiform or hemispherical, and scattered over the whole surface of the dental plate.

1. P. Owenii.

GENUS X. GYRONCHUS. Only yet known by its upper jaw, which resembles that of Pycnodus; but the middle row of teeth on the vomer is arranged longitudinally, instead of transversely. Size probably small.

1. G. oblongus.

GENUS XI. ACROTENMUS. The molar teeth, instead of the regular rounding of the crown, have a salient ridge like a crest.

1. A. faha.

GENUS XII. PERIODUS. Teeth, instead of the general form of the Pycnodonts, have a deep groove near the crown, so as to present, in a transverse section, the form of a hat, with its wide brim turned up.

1. P. Kazigili.

GENUS XIII. PHYLLODUS. Dental plates present a form like that of a leaf, the posterior part being contracted, as if for the attachment of a petiole; the middle row are the largest. A tooth consists of a mass of united plates, more or less flattened, in number from four to ten, which are not more than a quarter of a line in thickness each. Only known from the teeth.

1. Ph. tulasnei. 2. Ph. planus. 3. Ph. polyodus. 4. Ph. marginalis. 5. Ph. medius. 6. Ph. irregularis.

FAMILY V.—SCHLERODERMI.

Palatine arch immoveable; muzzle salient, armed with a few distinct teeth. Scales flat, in the form of large rhomboidal, or polygonal plates, placed obliquely on the body, which they wholly cover. Ossification of the skeleton, as if retarded, fibrous.

GENUS I. OSTRACON. This genus has several living representatives, but only one fossil species yet known. Body covered with an osseous case, consisting of plates firmly united, forming an inflexible covering, so that the fins and tail are alone moveable. Mouth with small lips, covering the sockets of the teeth.

1. O. micraeus.

GENUS II. ACANTHODERMA. Approaches the genus Balistes among living fishes. The scales or plates appear from their impressions in the rock to have possessed small points rising from their surface. Skeleton robust; vertebrae thick, and short; the spinous apophyses long and strong. First dorsal fin has a long spinous ray; the second dorsal and the anal have only very slender soft rays; caudal slender, composed of articulated dichotomous rays.

1. A. ovale. 2. A. spinosum.

GENUS III. ACANTHOPLERUS. Allied to the Balistes; with a dorsal spine, but with a more slender form. Dorsal spine strong; two strong spines also to the ventrals. Skin covered with asperities that leave fine granular impressions in the rock.

1. A. serratus. 2. A. brevis.

GENUS IV. GLYPTOCEPHALUS. This large genus discovered by König. Head covered with symmetrical rows of tubercles, which send out rays passing from their centre to the circumference of each plate.

1. G. radatus.

GENUS V. BLOCCHUS. Body very long, like an eel; head the thickest part of the fish, with a very long beak. Teeth scopular. Vertebrae very long and slender. Enamelled scales rhomboidal, with their angles in the longitudinal and transverse direction of the fish.

1. B. longirostris.

GENUS VI. DERCEITIS. Body and head elongated; beak narrow; upper jaw longer than the lower; both armed with teeth, which are long and conical, and alternating with smaller teeth. Vertebrae robust, longer than high, expanded at the articulating surfaces, but more slender in the middle. Pectorals very large; ventrals very near pectorals, short, with few rays; dorsal extends over almost all the back, reaching from before the ventrals to the tail; anal half the length of the dorsal. Sides covered with three rows of osseous shields, like those of the sturgeon, in form like the ace of hearts, with a granular surface.

1. D. elongatus. 2. D. scutatus.

GENUS VII. RHINELLUS. Small elongated body, with a slender beak. Two distinct dorsals, one near the head, the other near the tail; caudal large and forked. Sides covered with three rows of shields, like the last genus, from which it differs in having two dorsals.

1. Rh. fuscatus. 2. Rh. nasalis.

FAMILY—VI. ACIPENSERIDEI.

The existence of fossil fishes resembling the sturgeon, in the Jurassic and tertiary formations, has been proved by the discovery of their large dermoid plates; but their bones, which were chiefly cartilaginous, have disappeared. These plates have a thin coat of enamel.

GENUS I. ACIPENSER. This genus has much resemblance to the living Acipenser ruthenus.

1. A. toliapicus.

GENUS II. CHONDROSTEUS. This has no living representative, but the form of the plates show that it belongs to this family.

1. Ch. acipenseroides.

FAMILY VII.—GYMNODONTEL.

The palatine arch is immoveable; jaws covered with a case of ivory, formed of united teeth. Scales salient, with sharp spines placed obliquely to the body, which they wholly cover. Skeleton fibrous, with imperfect ossification.

GENUS I. DIODON. Orbicular body, sometimes elongated, with numerous sharp spines. Head thick, and obtuse. The bony plate of the jaws divided into two by a fissure, so as to represent two teeth in each jaw, as in living Diodon.

1. D. tenuisimus. 2. D. crinaceus. 3. D. Scilla.

FAMILY VIII.—LOPHOBRANCHIATI.

Branchiae united into little rounded tufts. Body elongated, angular, covered with angular scales. Skeleton osseous. Muzzle tubular, terminated with small free jaws.

GENUS I. CALOSTOMENA. Snout tubular, resembling the living Hippocampus; but there is a rounded fin at the end of the tail. Sides have three principal rows of oblong scales, which are higher than broad, and become smaller towards the tail; on the belly is a fourth row of small size.

1. C. brevissimum.

GENUS II. SYNGNATHUS. One anal, one caudal, and one dorsal fin; which last is far back.

1. S. ophiopterus, v. typhle.

FAMILY IX.—CEPHALASPIDEI.

Whole body and head covered by a few large shields or plates, which are not imbricated. Tail, which is heterocercus, covered with imbricated scales, without a true caudal fin. Instead of pectorals, this family have two long, bony stilettes. The place of vertebrae is supplied by a dorsal cord, like that of embryo fishes and the sturgeons.

GENUS I. PTERICHTHYS. No separation between head and trunk. The lateral anterior plates of the trunk touch the mesial line. The bony processes representing the FOSSIL ICHTHYOLOGY.

The pectorals are long. It was at first supposed to be an insect, but determined to be a fish by M. Agassiz. The species known are—

1. P. Milleri. 2. P. productus. 3. P. latus. 4. P. cornutus. 5. P. testudinariums. 6. P. oblongus. 7. P. cancriformis. 8. P. major.

GENUS II. PAMPHIRACTUS. Head and trunk distinct. Anterior lateral plates of the trunk separated by a mesial shield of enormous size, which forms a large portion of the surface of the carapace, and its anterior margin touches the head, the plates of which are separated from the carapace by a transverse line. Pectoral appendages like those of the last genus. It was at first mistaken for a Pterichthys.

1. P. hydrophilus.

GENUS III. POLYPHEACTUS. The only known specimen of this genus, consisting of plates of the head, was communicated by Professor Traill to M. Agassiz, and is figured by him in his Poissons Fossiles du Vieux Grès Rouge, Tab. 27, fig. 1. The head-plates are numerous, and finely sculptured with concentric lines, presenting the appearance of a mosaic. (See fig. 5.)

1. P. platycephalus.

GENUS IV. COCCOSTEUS. This genus wants the spinous processes which distinguish the Pterichthys, and therefore has no pectoral appendages; it has one anal, and one dorsal. The anterior of the trunk is covered by a single large shield. Mouth furnished with small, equal, conical teeth.

1. C. decipiens. 2. C. cuspidatus. 3. C. oblongus. 4. C. maximus.

GENUS V. CEPHALASPIS. Head covered by one large shield-shaped plate, with lateral prolongations extending some way along the sides of the animal, which seem to be spines united to the suborbital bones, as in the Gurnard. Body narrower than the head, and covered by vertical rows of scales. No ventral nor pectoral fins; two dorsals, the first rising just behind the head and reaching nearly to the middle of the back; the second ends near the root of the tail; the anterior of the anal is opposite to the middle of the second dorsal; the first rays of all the fins only are osseous.

1. C. Lyellii. 2. C. rostratus. 3. C. Lewisii. 4. C. Lloydii.

ORDER II.—PLACOÏDEI.

The order, named from the tabular form of their dermoid covering, consists of portions of the genera Squalus and Rajia, of the Linnean system, and is one of the most difficult branches of fossil ichthyology, because in most instances all that remain to us are the spinous appendages of the animal, the teeth, or a few scales. The spines, however, have a character which demonstrates them to have belonged to cartilaginous fishes. The spines consist of a single piece, the base of which has a distinct talus, that has been inserted in the flesh, and not articulated to any part of the skeleton, as is the case with the defensive spines of all osseous fishes. They have besides a groove in their posterior and inferior surface, more or less deep, which is often carried far into the interior of the spine, and even to its extremity. Their skeletons having been cartilaginous have been easily broken up, and have disappeared in the geological changes of the strata, in which their remains are imbedded; and it is only by a careful comparison of the fragments that remain with analogous parts in living species, that they can be referred to genera and species. Their skeletons are very rarely preserved; their moveable teeth are generally detached from the jaws; their fins, little connected with their skeleton, render it difficult to recognise their position on the animal. The scales of Placoids have great diversity of form and structure. Sometimes they consist of little scaly plates variously truncated at their posterior margin, as in the shagreen of the skin of the shark; another sort consists of large rounded plates, with a loop in the centre, which sometimes terminates in a sharp prickle or spine rising out of a circular hollow, as in the skate. If this animal be taken as a type of the structure of such parts in this order, the circular base is formed of cartilaginous fibrous tissue, on which the calciferous tubes radiate from the spine to the margins of the scale, just as if it were a tooth implanted in a jaw. This structure cannot be traced in the minute granulations on the skin of the shark; but probably the structure is similar in all the scales of Placoids.

In the magnificent work of M. Agassiz, the spines of Placoids, which were described by Dr Buckland and Mr De la Beche as Ichthyodorulites, were at first mistaken for the defences of osseous fishes, as the Saurus and Balistes; but were proved by M. Agassiz to belong to the rays of the fins of cartilaginous species; a conclusion to which it appears that Buckland and De la Beche had also arrived by their own researches. The term has been retained by Agassiz, to include certain genera which we only know by these osseous rays.

The form of Placoid scales will be understood from figs. 4 and 5.

DIVISION I.—ICHTHYODORULITHES.

They are characterized as the conspicuous osseous fin-rays which rise from a broad base, forming a talus to the spine, without the least appearance of the two apophyses that mark the basal joint of the spinous rays of osseous fishes.

GENUS I. ONCHUS. The spinous rays are of medium size, the surfaces longitudinally grooved, with rounded ribs between their channels, more or less broad. Most of the species have these growing on all their surfaces; but one species has the posterior surface smooth.

1. O. Marchionii. 2. O. tenuirostris. 3. O. arenatus. 4. O. sulcatus. 5. O. hamatus. 6. O. semistriatus.

GENUS II. CTENACANTHUS. Immense semi-compressed rays, broad at the base, the posterior cavity rather small, with a few small spines on the posterior surface, and punctated longitudinal striae.

1. Ct. major. 2. Ct. tenuistratus. 3. Ct. brevis. 4. Ct. ornatus.

GENUS III. ORCANTHUS. Rays thick, and very broad at base, with asteroid delineations on the portion above the flesh; no posterior spines, which distinguishes them from Asterocanthus, which occurs, not like this genus in the coal, but in the oolite formation.

1. O. Milleri. 2. O. pastosus. 3. O. minor.

GENUS IV. GYRACANTHUS. Rays have deep grooves and intervening ridges extending obliquely on the surface, from the middle of the anterior to the posterior part of the ray, and abutting those on the mesial line.

1. G. formosus. 2. G. tuberculosus. 3. G. Alnariensis.

GENUS V. TRISTECHUS. Rays with strongly marked longitudinal grooves on all the surfaces above the flesh, with often coalescing striae, while the base is simply finely striated. On the anterior surface there are three keels, the central the most prominent; the two lateral keels divericate as they descend; striae between the keels.

1. T. arenatus.

GENUS VI. PYTHACANTHUS. Rays have the form of a slightly bent sickle, insensibly growing thinner towards the point, and laterally compressed, with the anterior edge presenting an obtuse keel; its posterior edge carries teeth; the surface ornamented with fine thick-set placae.

1. Pt. sublatus. 2. Pt. Paugasi. 3. Pt. dubius.

GENUS VII. SPHENACANTHUS. Rays with well marked grooves and ridges, from top to bottom; anterior surface rounded; posterior flattened, smooth, with crenelled, but not toothed edges.

1. S. serratus. FOSSIL ICHTHYOLOGY.

GENUS VIII. NEMACANTHUS. Rays laterally compressed and flattened; anterior edge has a keel surmounted by a rounded fillet, and divided from the rest of the ray by a slight channel; on the exterior edge are several rounded knobs, and along the channel minute tooth-like projections; except where the knobs exist, the surface is longitudinally finely striated. The internal cavity is small, extending only to half the thickness of the ray at the base, and becoming a mere line where the knobs commence.

1. N. mollifier. 2. N. filifer.

GENUS IX. LEPTACANTHUS. Dorsal fins beset with small, flat, ensiform spines, the posterior part of which is armed with short teeth, and the anterior edge sharp; the rays marked by numerous fine longitudinal striae.

1. L. tenuispinus. 2. L. semistratus. 3. L. serratus. 4. L. longispinus.

GENUS X. ASTERACANTHUS. Rays generally large, slightly arched, rounded anteriorly, and armed with a double row of close-set teeth on their posterior edge, while their surface is covered with starry tubercles; base smooth, with a wide open groove on its posterior part.

1. A. ornatissimus. 2. A. acutus. 3. A. minor. 4. A. semiluteus.

GENUS XI. PERSTACANTHUS. Rays very long, and much compressed, so that their posterior cavity rather resembles a delicate fissure than an organic cavity; anterior edge as sharp as a knife, and so is the posterior, which is provided with sharp, flat, triangular teeth, like those of a saw.

1. P. securis.

GENUS XII. MYRIACANTHUS. Rays rounded, but with something of a quadrilateral form, from the arrangement of two series of spines on its posterior side, which are compressed and sharp, with their points towards the apex of the ray. The surface between these ranges of spines is finely longitudinally striated; the anterior face has a row of larger spines of the same form down its centre.

1. M. paradoxus. 2. M. retroversus. 3. M. granulatus.

GENUS XIII. LEIACANTHUS. Rays slightly curved, one-third part buried in the flesh, finely striated, with an aperture posteriorly, which leads into a pulpar cavity, reaching nearly to the sharp point of the ray; the surface of the exposed part is marked by longitudinal ridges of a rounded form, separated by furrows as deep. No teeth on the posterior side of the ray.

1. L. falcatus.

GENUS XIV. SPINAX. Of this genus there are living species; and the rays of the fossil resemble those of the existing species, but are much larger, proportionally thicker, straighter, and more rounded.

1. S. major.

GENUS XV. CHIMERA. Dorsal ray like that of Spinax, but differs in being more flat, and having dentations on its posterior edge, and also by a projecting anterior border. The jaws of four species have been found in the chalk by Dr Buckland.

1. Ch. Mantelli. 2. Ch. Egertonii. 3. Ch. Agassizii. 4. Ch. Tesseli. 5. Ch. Bucklandi. 6. Ch. Townsendii. 7. Ch. Johnsonii. 8. Ch. brevirostris. 9. Ch. Helvetica. 10. Ch. Dutertrei. 11. Ch. emarginatus. 12. Ch. Dufrenoyi. 13. Ch. Beaumontii. 14. Ch. Colei. 15. Ch. Owenii. 16. Ch. regalosa. 17. Ch. neglecta. 18. Ch. carvillensis. 19. Ch. Sedgwickii. 20. Ch. falcatu. 21. Ch. pelitacina.

GENUS XVI. PLEURACANTHUS. All the surfaces of the rays rounded, depressed, and armed on each edge towards the base by a row of arenated teeth; along the posterior surface is a deep, wide, round groove.

1. P. levisimus.

The remaining genera of Placoids are chiefly determined by their teeth, though the two first genera are also well characterized by the spinous rays of their fins. The labours of Agassiz on these fishes have been ably assisted by the researches of the Prince of Musignano, of Müller and Henle, and above all, by the admirable investigations of Owen in his Odontography, a work that has thrown much light on the whole zoological Division of the Vertebrata.

DIVISION II.—PLAGIOSTOMI.

Family I.—CESTRACIODONTEL.

The living representative of this family is Cestracion Philippii of Australia. The form of the teeth is better adapted for crushing or grinding to shreds, than for cutting.

GENUS I. HYBODUS. Besides the teeth of this genus, we possess some of the osseous rays, and even of their fins. They possess two dorsals, the osseous rays of which are of considerable size, with roots equal to one-third of their whole length concealed in the flesh. The surfaces of these rays present longitudinal furrows, divided by rounded ridges; they have a gentle curvature, with a flattened posterior surface, which is armed with two rows of large, sharp serratures, gradually approximating, and finally coalescing into one row. The teeth are peculiar, and are rather thin than massive; the central projection of each tooth is a lengthened cone, subulate or pointed; and on the same base arise smaller flanking cones, decreasing in size as they recede from the central cone. These compound teeth sometimes amount to four in each side of the jaw. The enamel of the teeth consists of vertical folds, which in some species can be seen at even the apex of the central cone. The first twenty-two species are chiefly characterized by their osseous rays, the succeeding species by their teeth.

1. H. dorsalis. 2. H. apicalis. 3. H. marginalis. 4. H. striatus. 5. H. sulcatus. 6. H. leptodus. 7. H. acutus. 8. H. pleiodus. 9. H. striatus. 10. H. subcarinatus. 11. H. larvusculus. 12. H. crassus. 13. H. crassispinus. 14. H. minor. 15. H. curtus. 16. H. reticulatus. 17. H. formosus. 18. H. ensatus. 19. H. carinatus. 20. H. major. 21. H. dimidiatus. 22. H. tenius. 23. H. pyramidalis. 24. H. medius. 25. H. grossicus. 26. H. polyurion. 27. H. obtusus. 28. H. indatus. 29. H. raristatus. 30. H. dubius. 31. H. undulatus. 32. H. plicatus. 33. H. Mossgoodi. 34. H. angustus. 35. H. longiceps. 36. H. obliquus. 37. H. polycephalus. 38. H. capsidatus. 39. H. sublevis.

GENUS II. PYTHODUS. Teeth quadrangular, root and crown divided by a wide shallow groove; root coarse and porous, flat below, and gradually enlarging towards the crown, which suddenly expands beyond the root; interiorly the tooth consists of medullary and caligerous tubes arranged as in Cestracidae, but smaller in size. Dorsal ray very thick, and differs from that of the rest of the genera in not consisting of one piece, but seemingly formed of several layers, intimately soldered together, but perceptible in the longitudinal furrows; the anterior of the ray has bosses formed by the intersections of transverse ribs seen on its sides.

1. Pt. spectabilis. 2. Pt. gibberulus. 3. Pt. arenatus. 4. Pt. articulatus. 5. Pt. altior. 6. Pt. sulcatus. 7. Pt. concentricus. 8. Pt. decurrens. 9. Pt. acutus. 10. Pt. Knerii. 11. Pt. latilatus. 12. Pt. mamillarius. 13. Pt. Morioni. 14. Pt. polygrus.

GENUS III. CTENOPTYCHIUS. Teeth somewhat like those of Oroodus, but more compressed, with the elevated central ridge dentate.

1. Ct. apicalis. 2. Ct. pectinatus. 3. Ct. denticleatus.

GENUS IV. ORODUS. Teeth elongated, with the central part forming a transverse, obtuse cone, of which the longitudinal diameter is much the greatest.

1. O. cinctus. 2. O. ramosus.

GENUS V. PSAMMODUS. Crown of teeth found formed of minute vertical tubes, which give the surface the appearance of being sanded; they appear to have been in several ranges in the jaw.

1. Ps. rugosus. 2. Ps. porosus.

GENUS VI. HELODUS. Formation of teeth like the last, with which it was by Agassiz at first confounded, as were FOSSIL ICHTHYOLOGY.

the three following genera also; but in this genus the crown of the tooth is perfectly smooth, with a conical elevation in the centre, and sometimes it has several such, but the central is most elevated.

1. H. simplex. 2. H. invissimus. 3. H. subteres. 4. H. gibberulas. 5. H. turgidus.

GENUS VII. CHOMATODUS. Teeth like those of Pseammodus, but the base of each is surrounded with a series of concentric plicae, more or less salient; they are generally elongated, with the crown either flat or slightly salient, and occasionally the edge is sharp.

1. Ch. cinetus. 2. Ch. linearis. 3. Ch. acuminatus.

GENUS VIII. COCHLIDUS. The crown of the teeth convoluted like a shell, instead of having them disposed in several rows.

1. C. contortus.

GENUS IX. STROPHODUS. Teeth elongated, narrow, truncated at each end, with more or less torsion in the longitudinal diameter; occasionally they are nearly straight, or only slightly bent; the crown without projection or ridge.

1. S. longidens. 2. S. reticulatus. 3. S. subreticulatus. 4. S. magnum. 5. S. tenuis. 6. S. irregularis. 7. S. radiopunctatus. 8. S. angustissimus. 9. S. elytra. 10. S. asper. 11. S. punctatus.

GENUS X. CERATODUS. Structure of teeth like Pseammodus, but they have only been placed in a single row; one of their sides is straight, the opposite has several strong projections.

1. C. altus. 2. C. latissimus. 3. C. curvus. 4. C. Kaupii. 5. C. planus. 6. C. parvus. 7. C. emarginatus. 8. C. gibbus. 9. C. Dedaclasi. 10. C. obtusus. 11. C. discuris. 12. C. Phillippii. 13. C. serratus. 14. C. heteromorphus.

GENUS XI. CTENODUS. These singular teeth look very like the valve of an echinoderm coeloid; but how fixed in the jaw is unknown.

1. Ct. alatus. 2. Ct. cristatus. 3. Ct. Robertoni.

GENUS XII. ACRODES. A fragment of a jaw was found showing teeth like the living Cestracion of Australia. The enamel covers a granular bony structure. The teeth has transverse ridges radiating from a longitudinal central one, not unlike in appearance to a contracted leech, for the petrifaction of which the tooth has often passed; in some species the central ridge is high, especially in the middle.

1. A. nobilis. 2. A. latus. 3. A. gibberulas. 4. A. undulatus. 5. A. leiolepis. 6. A. minimus. 7. A. acutus. 8. A. Gallardotii. 9. A. lateralis. 10. A. larva. 11. A. Braunii. 12. A. hirudo. 13. A. rugosus.

Family II.—SQUALI, OR SHARKS.

An elongated body; strong muscular tail; mouth below the muzzle; breathe through several open spiracles on the sides of the neck; generally sharp cutting teeth, which are moveable. Skeleton cartilaginous. From this last circumstance, we seldom find more of them fossilized than the teeth, and spines of the fins.

GENUS I. NOTIDANUS. Single dorsal, opposite to the space between the ventral and anal fins. Teeth composed of a series of toothlets, the first of which is crenulated on its anterior margin; the toothlets become smaller and smaller, and the last represent a fine serrature on the posterior margin of the tooth; the root broad and flat.

1. N. primigenius. 2. N. recurvus. 3. N. microdon. 4. N. petrinatus. 5. N. Munsteri. 6. N. serratisimus.

GENUS II. CORAX. Teeth solid, and resemble those of the living Galeus, except in the regularity of the serratures on the edges of the teeth.

1. C. pristidontus. 2. C. Kaupii. 3. C. falcatus. 4. C. appendiculatus. 6. C. affinis. 6. C. Egerioni. 7. C. planus.

GENUS III. GALEOCERDO. Teeth chiefly differ from those of Galeus by serratures on both edges, and from Corax by the greater size of those at the base. They are flat externally, and convex on the inside. Two of this genus are its living representatives, and five are fossil.

1. G. adunca. 2. G. latidens. 3. G. minor. 4. G. gibberulas. 5. G. denticulatus.

GENUS IV. SPHYRNA, v. Zygena. Unfortunately the determination of the fossil species is very difficult; for, in this genus, the teeth in both jaws differ much from each other; and we even find, in the same jaw of the living species, teeth with serratures on the edges, and some without them. The general form of the teeth resembles those of the sharks termed Prionodon; but these are more slender. The species referred by Agassiz to this genus are—

1. S. prisa. 2. S. lata. 3. S. denticulata.

GENUS V. HEMPRISTIS. Teeth have smooth points, but are distinctly serrated towards their base; they are pyramidal, broad at the base, and sharp pointed, with smooth enamel.

1. H. serra. 2. H. pascidens.

GENUS VI. CARCHARIAS. Teeth triangular, in several rows, serrated on both margins; enamel perfect; dentine presents a hollow cone.

1. C. telesis. 2. C. acutus.

GENUS VII. GLYPHIS. This genus separated from the last, because of the lanceet form of the teeth, which at the point resemble a sculptor's chisel, the root and base of the crown being a little enlarged.

1. G. hastalis.

GENUS VIII. CARCHARODON. Teeth chiefly differ from those of Carcharias by being solid within, and by their vast size. The living type is the Lamna of the Prince of Canino.

1. C. megadon. 2. C. rectidens. 3. C. subauriculatus. 4. C. productus. 5. C. polygyrus. 6. C. sulcoides. 7. C. auriculatus. 8. C. angustidens. 9. C. turgidus. 10. C. semiserratus. 11. C. lancolatus. 12. C. tollipicus. 13. C. heterodon. 14. C. megalotis. 15. C. leptodon. 16. C. discuris. 17. C. subserratus. 18. C. Escheri.

GENUS IX. OTODUS. Only known as a fossil. Teeth differ from Carcharodon by the total want of serratures on the edges, and being smaller, while they have a conspicuous collar on each side of the tooth; their form is wide, and their root large.

1. O. obliquus. 2. O. lanceolatus. 3. O. appendiculatus. 4. O. latus. 5. O. crassus. 6. O. semispicatus. 7. O. serratus. 8. O. yoshodus. 9. O. tricuspidus. 10. O. subspicatus. 11. O. trigonatus. 12. O. rectidens.

GENUS X. OXYRHINA. Teeth with the lateral collar of Otodus, in which they differ also from Lamna. Muzzle sharp.

1. Ox. hastalis. 2. Ox. xiphodon. 3. Ox. trigonodon. 4. Ox. plecitides. 5. Ox. Mantelli. 6. Ox. retrofexa. 7. Ox. quadrans. 8. Ox. lepidon. 9. Ox. Desorii. 10. Ox. crassa. 11. Ox. subinflata. 12. Zippel. 13. Ox. minuta. 14. Ox. meristodon, v. para-

doxa.

GENUS XI. LAMNA. Teeth have the lateral collar, but it is much less conspicuous than in Otodus; are flat and lamelliform, but less broad than in the last mentioned; and they have small lateral cones.

1. L. elegans. 2. L. cuspidata. 3. L. compressa. 4. L. denticulata. 5. L. acuminata. 6. L. crassidens. 7. L. Hopel. 8. L. ventralis. 9. L. acutissima. 10. L. contorta. 11. L. dubia. 12. L. gracilis. 13. L. subula. 14. L. raphidon. 15. L. Brouni. 16. L. duplex. 17. L. longidens. 18. L. plana.

Family III.—RAJA.

Distinguished by their horizontally flattened bodies, with the mouth placed below their disk, and the enormous development of their pectoral fins.

GENUS I. MYLOBATES. Known by the extraordinary size of the transverse dental plates, that supply the place of teeth in both jaws, but are longer and more flat in the lower than the upper jaw. The central teeth are elongated, and are supported on each side by much smaller lateral teeth, of an irregular hexagonal figure, in three rows. These teeth or plates are closely applied, and seem to pave the mouth. The living species are few, but they seem to have been very numerous in a former geological epoch.

1. M. micropleurus. 2. M. Stokesii. 3. M. gemopleurus. 4. M. Dixonii. 5. M. Regleyi. 6. M. variatus. 7. M. tollopusa. 8. M. punctatus. 9. M. maculata. 10. M. gyraeus. 11. M. heteropleurus. 12. M. jugalis. 13. M. Bronzignatis. 14. M. nitida. 15. M. angustus. 16. M. Colei. 17. M. Owenii. 18. M. Sternebergii. 19. M. Woodwardii. 20. M. canaliculatus. 21. M. lateralis. 22. M. marginalis. 23. M. acutus.

Genus II. Aetobates. Differs from Myliobates by the projection of the lower jaw, and the square truncation of the upper. Teeth all parallel to each other, and the lateral teeth are wanting.

1. A. sulcatus. 2. A. irregularis. 3. A. arenatus. 4. A. subarenatus.

Genus III. Zygorates. The dental plates disposed in several rows, diminishing gradually in size from the central to the lateral rows. The living species are found on the coast of Brazil; the fossil species in the crag formation.

1. Z. Studeri. 2. Z. Woodwardii.

Family IV.—Chimæra.

The fossil species were discovered by Dr Buckland, who recognised the jaws and teeth. The latter are undivided plates. The family more numerous in former epochs than now.

Genus I. Chimæra, v. Ischyodon. The living species have but one branchial opening; the upper jaw represented only by the vomer; and this and also the lower jaw are furnished with hard undivided plates instead of teeth.

1. Ch. Egertonii. 2. Ch. Agassizii. 3. Ch. Tessoni. 4. Ch. Bucklandii. 5. Ch. Townsendii. 6. Ch. Johnsonii. 7. Ch. brevirostris. 8. Ch. Helvetica. 9. Ch. Dutertrei. 10. Ch. emarginatus. 11. Ch. Duforeyii. 12. Ch. Beaumontii. 13. Ch. Colei. 14. Ch. Owenii. 15. Ch. rugosus. 16. Ch. neglectus. 17. Ch. curvifrons. 18. Ch. Mantelli. 19. Ch. Sedgwickii. 20. Ch. falcata. 21. Ch. pithecina.

Genus II. Elasmodus. Differs from Chimæra by the extreme shortness of the lower jaw, as was first pointed out by Sir Philip Egerton. The symphysis of the jaw flat, with dental plate truncated, and sloping backward.

1. E. Greenoughii. 2. E. Hunteri.

Genus III. Edaphodus. Characterized by Buckland as having on the superior maxillaries three tubercles of dentine projecting from the bone; on the interior maxillary are two smaller tubercles, placed obliquely on the dentaledge.

1. E. Bucklandii. 2. E. leptognathus. 3. E. eurygnathus.

There are some other Placodons which are imperfectly known from small fragments, described chiefly by the German naturalists, Count Münster, MM. Müller, Henle, and Wagner, which we can here only slightly notice.

Genus I. Janassa. This has much of the character of the genus of the Myliobates; with teeth somewhat like those of Zygorates; they have a tubular structure, and are smallest towards the point, placed in three principal ranges, with small lateral teeth.

1. J. angula. 2. J. Hamboldtii. 3. J. bituminosa.

Genus II. Dicta. A nearly complete impression shows this to have a flattened form, with large rounded pectorals prolonged on the sides of the head.

1. D. striata.

Genus III. Aellopos. From a specimen in the museum at Munich, it has vertebrae like a Galeus, as long as high, with a smooth surface. The second dorsal fin is large, of a pyramidal form; the caudal much elongated; the shagreen of the skin finely and uniformly granular.

1. A. Wagneri. 2. A. elongatus.

Genus IV. Scylliodus. This is contained in the collections of Lord Enniskillen and Sir Philip Egerton. It is a Squalus of mean size, found in the Kentish chalk.

The teeth are small, tricuspid, the middle point only cutting; the base large, which keeps the lateral points distant from the cutting one. Jaws dilated at the sides, narrowing towards the symphysis.

1. A. antiquus.

Genus V. Thylina. Discovered by Count Münster in the chalk of Baumberge. Both dorsals are behind the insertion of the ventrals; the second dorsal is opposite to the anal, which it exceeds in size. Form that of a true Scyllium. The inferior angle of all these fins is rounded.

1. Th. angusta. 2. Th. prissa; this last, found in the lias of Lyme Regis.

Genus VI. Arthropterus. Observed by Agassiz in the lias of Bristol; only known by its fins, which are five inches long, composed of articulated, cylindrical rays; dilated at their ends, and sending off parallel branches to very distant articulations; unequal in different parts of the same ray.

1. A. Rileyi.

Genus VII. Squalo-raja, v. Spinacorhinus. From the lias of Lyme Regis. The prolongation of the head is owing to a projection analogous to the saw of a Pristis, composed of two parallel pieces, of which the larger and lower receives the other. Around this beak are spines, like those on the skate. Jaws transverse, and placed before and below the orbits, with very small pointed teeth.

1. Sq. polypondyla.

Genus VIII. Asteropterus. The collection of the Geological Society of London possesses a small fish like a ray, from Solenhofen; but the vertebrae have more the form of a shark than a ray. All the surface is covered with starlike spinous scales, the largest of which are in the middle of the back. It has eight pairs of ribs on the sides of the pelvic vertebrae, which are long and slender, unlike the skeleton of a ray. Fins with flat, simple, transversely articulated rays.

1. A. platypterus.

Genus IX. Cycloarthrus. In the Bristol museum, a fish which cannot be referred to any known species of ray, though like them. The rays are cylindrical. Thick and short towards the base of the fins. The shagreen very fine.

1. C. micropterus.

Genus X. Euryarthra. Count Münster has a fin from Solenhofen, of large size, with flat, broad rays, composed of a few large articulations. The animal seems to have been very large.

1. Eu. Munsteri.

Genus XI. Pristis. The saw of this species, found in Sheepy, is in the British Museum; and a similar one of the same genus in Sir P. Egerton's collection. They belong to a species no longer existing. They have on the superior surface two grooves. The two osseous plates composing this beak are supported by vertical pillars, that lie side by side.

1. P. blauelatus. 2. P. Hastingsii.

Genus XII. Trygon. This genus belongs to the Rays, and the two known species are found at Monte Bolca. The genus is distinguished by the double dentate spine or sting, with which the tail is armed. Both species occur at Monte Bolca.

1. T. Gazzea. 2. T. oblonga.

Genus XIII. Torpedo. A large fish, with the appearance of the existing Torpedo, occurs at Monte Bolca. The disk of the body is nearly circular; the tail short and robust.

1. T. gigantea.

Genus XIV. Narcopterus. In the museum of Padua is a fish which Agassiz mentions under this name, from ORDER III.—CTENOÏDEI.

This order, unlike the two last, has many living representatives in all its families. The character is, "scales circular, more or less elongated, formed of osseous plates, toothed or dentate on their posterior margins." The fossil families are nine, and many of the species are found in excellent preservation.

FAMILY I.—PERCOÏDEI.

Body oblong; scales rough; opercula strongly dentate or spinous. Teeth on the intermaxillaries, the forepart of the vomer, the lower jaw, and frequently on the palate. Strong anterior spinous rays on the anterior part of the back, forming a fin, quite distinct from the soft rays, or uniting with them in a common membrane. Ventral fins often thoracic, i.e., anterior to the pectorals.

GENUS I. SPHEOCEPHALUS. One dorsal, with some spinous rays only at its anterior margin; this fin is of small extent, and scarcely surpasses the size of the anal. Head wedge-shaped.

1. Sph. fissicaudus.

GENUS II. HOLOPTERYX. Spinous portion of the dorsal formed of very thick rays, and as large as the soft part; this fin extends as far as the end of the anal. Bones of the head dentate.

1. H. antiquus.

GENUS III. BERYX. A single dorsal, with a few spinous rays only in its anterior. Head thick, and very obtuse.

1. B. ornatus. 2. B. radiana. 3. B. microcephalus. 4. B. Zippel. 5. B. Germanus.

GENUS IV. ACANUS. Spinous portion of the only dorsal very large, formed of thick rays longer than the soft rays. Several strong rays before the anal.

1. A. ovalis. 2. A. Regeloy. 3. A. oblongus. 4. A. minor. 5. A. arcatus.

GENUS V. PODOCYS. Lower jaw projecting. Ventrals much developed, with long rays. Dorsal extending to the nape.

1. P. minutus.

GENUS VI. ACROGASTER. Abdominal region large, and salient. A few spines before the dorsal, which extends not below the middle of the back; anal as long as the dorsal.

1. A. parvus.

GENUS VII. MYRIPISTIS. Preoperculum bristled with two parallel rows of dentations, but without a spine at its angle. All the opercula and the bones of the face and cranium are equally dentate. Two nearly equal dorsals.

1. M. homopterygus. 2. M. leptacanthus.

GENUS VIII. HOLOCENTRUM. Operculum and preoperculum equally armed with spines, and the latter has besides, at its angle, a strong one directed backwards; cranial bone and the suborbital bones are also dentate. Two dorsals; the first of which is formed of large sharp spines, and is larger than the second.

1. H. pygmaeum. 2. H. pygmaeum.

GENUS IX. PRISTIGENYS. Suborbiculars strongly dentate. Spinous rays of the dorsal longer than the soft, and occupying it to a greater extent.

1. P. macroptalmus.

GENUS X. ENOPLOUS. Broad compressed body. Anterior dorsal very high. Ventrals very large.

1. E. pygopterus.

GENUS XI. SMERDIS. First suborbital bone strong, dentate; preoperculum equally so, but without a spine at its angle; operculum terminates behind by a rounded projection. Two very narrow dorsals; caudal forked.

1. S. micranthus. 2. S. pygmaeus. 3. S. minutus. 4. S. macraeus. 5. S. ventralis. 6. S. latior.

GENUS XII. PERCA. Two approximate dorsals. A strong spine at the angle of the operculum; preoperculum dentate, especially below; interoperculum, at its inferior margin, as well as the suboperculum, less dentate. There are dentations also at the scapularies and angles of the humerus.

1. P. lepidota. 2. P. Beaumontii. 3. P. angusta.

GENUS XIII. LABRAX. Operculum with a double point; suborbitars, interopercula, and subopercula smooth; preoperculum dentate, rounded at its angle, with large teeth at its inferior margin; opercular pieces scaly.

1. L. lepidotus. 2. L. schizurus. 3. L. major.

GENUS XIV. APOGON. Two very distinct dorsals. Preoperculum with a double dentate margin. Body short. Scales large.

1. A. spinosus.

GENUS XV. LATES. Preoperculum dentate, with a strong spine at its angle, directed backwards; humeral angle dentate. Two dorsals. Tail rounded.

1. L. gracilis. 2. L. gibbus. 3. L. notatus. 4. L. macrurus.

GENUS XVI. CYCLOPOMA. Operculum terminated by a thick point, very strong and sharp; preoperculum strongly dentate, and the strongest dentations on this bone are at its inferior margin, and directed forward; humeral angle rounded. Two dorsals slightly united at their base; caudal rounded.

1. C. gigas. 2. C. splendens.

GENUS XVII. DULES. Jaws furnished with finely scupolar, or velvet-formed teeth. Opercula spinous; preoperculum dentate. Six branchiostegous rays. Dorsals united.

1. D. temnotopterus. 2. D. medius.

GENUS XVIII. PELATES. Operculum terminated by a strong spine; preoperculum dentate. Teeth scupolar. Dorsal has numerous spinous rays, and this part is scarcely distinguishable from the soft part of the fin.

1. P. quinquedentatus.

GENUS XIX. SERBIANUS. Spinous and soft portions of the dorsal united. Jaws with canine teeth, mingled with scupolar teeth. Operculum terminated by two or three flat spines; preoperculum finely dentate. Seven branchiostegous rays. Cranium and opercular pieces scaly.

1. S. microstomus. 2. S. occipitalis. 3. S. ventralis.

FAMILY II.—SPAROÏDEI.

The living fishes of this family were involved in much confusion, until remodelled by Valenciennes. Its fossil fishes are not numerous. The most ancient occur at Monte Bolca, and among these there is one extinct genus, Sparodus; all the other genera have living representatives, though the species which occur as fossils no longer exist.

The Sparodids are characterized by a mouth not protractile, by the absence of palatal teeth, and of spines or dentations on the opercular bones; no bulging of the cranial bone, and no scales on their vertical fins.

GENUS I. DENTEX. Deep and compressed body. Head large; conical teeth in one row on the edges of the intermaxillaries and inferior maxillaries; the anterior teeth extend in a hooked form beyond the other teeth. Cheeks scaly.

1. D. leptacanthus. 2. D. microdon. 3. D. cenisispinus. 4. D. breviloops. 5. D. ventralis. 6. D. Faunell.

GENUS II. PAGELLUS. Two rows of small molar teeth on the intermaxillaries and maxillaries, in the form of pavements, with small conical slender teeth in the front of the jaws.

1. P. microdon. 2. P. leptesteus.

GENUS III. SPARNODUS. A single row of large, conical, FOSSIL ICHTHYOLOGY.

Ctenoidei. short, and obtuse teeth on the edge of the intermaxillaries and inferior maxillaries. On the back and behind the anal fin are grooves, in which the anal and dorsal fins may lie.

1. S. macropteryx. 2. S. ovalis. 3. S. altivelis. 4. S. micranthus. 5. S. elongatus.

Genus IV. Sargus. Body small, elongated, much compressed, and deep, especially in the middle. Cutting incisors in the interior part of the intermaxillaries and inferior maxillaries.

1. S. Caviert.

Family III.—Scienoiidei.

This family presents most of the characters of the Percoids, except that they have no teeth on vomer and palate, which are always smooth. The head, and especially the muzzle, is rounded, so that the outline presents an ogre Gothic arch. There are but two fossil genera.

Genus I. Pristiforma. The spinous rays of the dorsal are united to the soft rays; seven branchiostegous rays. Muzzle much rounded; mouth small. Operculum obtuse.

1. P. furestrum.

Genus II. Odontes. Spinous part of dorsal very high, and separated from the soft rays by a slope. One row of thick conical teeth, which are short, on the intermaxillaries and maxillaries; preoperculum finely dentate. Cavernous bone round the orbits. Six branchiostegous rays.

1. O. sparoides.

Family IV.—Cottoidei.

Head large, depressed, cuirassed, furnished with spines or tubercles. Two dorsals.

Genus I. Cottus. Head and body at its anterior thick and broad, tapering to the tail. Head tuberculated or spinous. Dorsals distinct; the first narrow; inferior rays of pectorals simple; ventrals with few rays. Branchiostegous rays six.

1. C. brevis. 2. C. aries. 3. C. papyraceus.

Genus II. Pterygocephalus. Spinous dorsal rays very long, separate, and reaching to the head, while the soft part of this fin occupies all the back. Caudal large, rounded. Scales carinated.

1. P. paradoxus.

Genus III. Callipteryx. Body large, elongated. Few spinous rays in the anterior of the dorsal, which extends along the whole back; anal also very extended. No scales have yet been found. The last caudal vertebra dilated into a plate, and caudal fin ample.

1. C. speciosus. 2. C. recticaudus.

Family V.—Gobioidel.

Ventral-thoracic fins united by their inner margins so as to form a sort of funnel more or less open. Dorsal has simple slender rays, which sometimes mingle with the soft rays, or form sometimes a distinct fin. Six branchiostegous rays.

Genus I. Gobius. Two distinct dorsal fins. Ventral united. Teeth finely scopolar.

1. G. macracanthus. 2. G. microcephalus.

Family VI.—Teuthys.

An oval compressed body; a small mouth, not porrectile, with a single row of teeth in each jaw; none on the palatines nor tongue. Dorsal single; caudal nearly square. Head sloping very rapidly.

Genus I. Acanthurus. Teeth cutting, and dentate on the edges. A strong, cutting, and mobile spine on each side of the tail.

1. A. tenellus. 2. A. ovalis.

Genus II. Naseus. Front more or less prominent. Teeth conical. Four branchiostegous rays. Ventral has Ctenoidel. three soft rays. Tail with fixed spines.

1. N. nuchalis. 2. N. rectifrons.

Family VII.—Aulostomata.

This family contains several genera which have little resemblance with each other, except in having the mouth tubular, or like a flute. Body elongated, but some are thoracic and others abdominal fishes. The soft dorsal and anal fins are placed far back. Scales pectinated, as in Chondrodon.

Genus I. Amphistyle. Back cuirassed with large scale plates, with the anterior of which the first spinous ray of the dorsal is articulated.

1. A. longirostris.

Genus II. Aulostoma. Ventrals abdominal; the soft dorsal opposite to the anal, and far back; a few free spines are before the dorsal. Mouth-tube long and compressed; jaws without teeth.

1. A. boleensis.

Genus III. Fistularia. Mouth-tube very long, and depressed; small teeth on the intermaxillaries and inferior maxillaries. A single dorsal opposite to the anal; middle ray of the caudal filamentous.

1. F. tentirostris. 2. F. Kosigii.

Genus IV. Rhamphosus. An immense spinous ray, dentate on its posterior surface, is inserted in the nape; a soft dorsal opposite to the anal fin; caudal squared. Muzzle projecting as a nose above the jaws.

1. Rh. aculeatus.

Genus V. Urophex. Body elongated, cylindrical, terminated by a large cuneiform fin. Mouth-tube elongated, as in Fistularia.

1. U. fistularis.

Family VIII.—Chætodonta, v. Squamipennæ.

Body compressed, appearing more or less deep according to the proportion of the vertical fins, the soft parts of which have scales on them, so as to render it difficult to see the beginning of those fins. Some of them have very fine scopolar teeth.

Genus I. Semiophorus. Dorsal very high anteriorly, and all soft, except the fins, ray, and a few small spines; it extends along the whole back; anal much less; ventrals very long. Profile very perpendicular.

1. S. velifer. 2. S. velicanus.

Genus II. Ephippus. Anterior of dorsal formed of very large spinous rays, which are not covered with scales. A deep groove exists in all the rays of both spinous and soft.

1. E. longipinnis. 2. E. oblongus.

Genus III. Scatophagus. Two dorsals, of which the anterior is formed of thick spines, the first the longest; the anal has four spines. Scales very small.

1. S. frontalis.

Genus IV. Zanclus. Few spinous rays in the dorsal; but elongating rapidly, where collected at the very high anterior of the dorsal. Muzzle very prominent.

1. Z. bravirostris.

Genus V. Macrostoma. Mouth very large. Dorsal and anal low, but very long.

1. M. alium.

Genus VI. Holacanthus. At the angle of the preoperculum is a large needle-formed spine, directed backwards, the surface of which is usually dentate. Spinous dorsal rays strong, but less high than in Pomacanthus.

1. H. microcephalus.

Genus VII. Pomacanthus. Resembles the last, but with much longer dorsal spines.

1. P. subareatus.

Genus VIII. Platax. Body much compressed, being scarce distinguishable from the vertical fins, which are very FOSSIL ICHTHYOLOGY.

GENUS IX. PYGEUS. Dorsals united, the anterior spinous part formed of thick rays, the soft part rounded and accumulated by rays a little longer in the middle portion; anal conformed to the dorsal, but not so long. 1. P. gigas. 2. P. nobilis. 3. P. oblongus. 4. P. dorsalis. 5. P. nuchalis. 6. P. Coleanus. 7. P. Egertonii. 8. P. gibbus.

GENUS X. TOXOTES. Dorsal very far back, scaly on its soft portion, which is lost in the spinous part; anal resembles the dorsal, to which it is opposite. Lower jaw projecting. The living type is the T. jaculator of Bengal, which the fossil species much resembles. 1. T. antiquus.

FAMILY XI.—PLEURONECTES.

Characterized by want of symmetry between both sides of the body, the irregularity of the head, the eyes on one side of the body. Fins of back and abdomen invest also the head. Scales with rough points at their extremities.

GENUS I. RHOMBUS. Body very broad. Dorsal advancing to the border of the lower jaw, and prolonged, as is the anal to the caudal. 1. Rh. minimus.

FAMILY XII.—MUGILLOIDEL.

Body nearly cylindrical. Scales large, advancing to the top of the head. Two distant dorsals, the first consisting of a few strong spines; ventrals abdominal. Teeth minute.

GENUS I. MUGIL. Body short, covered with large scales. First dorsal consists of four spines. 1. M. princeps.

ORDER IV.—CYCLOIDEI.

They have been defined osseous fishes, with elliptical or circular scales, formed of horny laminae, without dentations on their posterior margins. From the varying size of the laminae composing them, they appear marked with concentric circular rings. This order does not correspond with any of Cuvier's divisions, but the structure of the scales is an excellent character for distinguishing either recent or fossil fishes. Agassiz subdivides this order into two great divisions.

DIVISION I.—CYCLOIDEI ACANTHOPTERYGEI.

FAMILY I.—SCOMBEROIDEI.

Body more or less elongated, generally fusiform, rarely squat. Ventrals either thoracic or jugular; ventrals without scales; dorsals either separate or contiguous, with or without finlets behind the second dorsal or anal fins; opercula without spines or dentations. Jaws with strong conical teeth, or with loose scapular teeth. Scales very small. Of all the Cycloids, the Scomberoids have the greatest number of living representatives.

GENUS I. GASTERONEMUS. Body compressed; abdomen very dilated. Thoracic ventrals supported by an immense pelvic bone, and composed of a long simple ray preceded by a small bonelet. Dorsal continuous. Head small. Teeth very small. 1. G. rhombens. 2. G. oblongus.

GENUS II. ACANTHONEMUS. Body squat. Dorsal continuous; spinous rays of the dorsal and anal exceedingly developed. Muzzle porrectile. Teeth scapular. 1. A. filamentosus. 2. A. Bertrandii.

GENUS III. VOMER. Body squat, compressed, wholly covered with very small scales. Head large, its profile much inclined. Ventrals thoracic; dorsals separate; fin-rays short and slender; vertebral apophyses stout; those of the abdomen curving forwards. 1. V. longispinus. 2. V. priscus. 3. V. parvulus.

GENUS IV. ZEUS. Body squat; compressed. Head large; muzzle porrectile. Spinous dorsal composed of very long rays; two anal; one spinous, the other soft; the soft dorsal and soft anal are flanked by large osseous and spinous shields; margin of the ventral has similar shields. Vertebre short; ribs very slender, and partly attached to very strong inferior apophyses. 1. Z. priscus.

GENUS V. LICHIUS. Body elongated, compressed. First dorsal composed of free, moveable spines, and of a fixed one directed forwards; two free spines before the anal. Teeth scapular. 1. L. priscus.

GENUS VI. TRACHINOTUS. Body short, elevated. Profile much inclined. First dorsal composed of free spines. Teeth scapular. 1. T. tenueculis.

GENUS VII. CARANGUS. Body elongated, compressed. First dorsal consists of free spines, rather long, without the spine projecting forwards; no free anal spines; second dorsal opposite to the anal; no finlets. Teeth scapular. 1. C. latior. 2. C. dorsalis. 3. C. analis. 4. C. maximus.

GENUS VIII. AMPHISTHMUS. Body broad and squat, probably flat. Dorsal continuous, occupying more than the half of the ridge of the back. Anal very large. 1. A. paradoxum.

GENUS IX. PALMIPHYTES. Body squat. Dorsals separate; pectorals very large. Pedicle of tail broad. Vertebre short and numerous. 1. P. longus. 2. P. brevis. 3. P. latus.

GENUS X. ARCHAEUS. Body more or less elongated. Vertebre long and few; interapophysal bonelets very slender. 1. Ar. Glaristanus. 2. Ar. brevis.

GENUS XI. ISURUS. Body squat. Head large. Pedicle of tail very narrow. Skeleton robust. 1. I. macrurus.

GENUS XII. PLEIONEMUS. Allied to Isurus, but body more lengthened. 1. P. macropondylus.

GENUS XIII. DUCTOR. Body elongated and cylindrical. Pedicle of tail broad. Vertebre long and few. 1. D. leptosomus.

GENUS XIV. THYNNUS. Body elongated. Dorsals contiguous; false pinnules or finlets behind the dorsal and anal fins. A corset of uncinate scales around the thorax. 1. Th. propterigius. 2. Th. Bolceanis.

GENUS XV. ORCYNUS. Body elongated. Dorsals contiguous; finlets behind the dorsal and anal fins; pectorals very long, which distinguish it from Thynnus. 1. O. lanceolatus. 2. O. latior.

GENUS XVI. CYRUM. Body elongated. Dorsals contiguous; finlets as in the last. Teeth large in both jaws. 1. C. speciosum. 2. C. macropomum.

GENUS XVII. GONIOGNATHUS. Habit of the Coryphaenae; but differs in the angular form of the jaws. 1. G. coryphaenoides. 2. G. maxillaris.

GENUS XVIII. ENCHODES. Teeth strongly developed, bulging on their interior, and flat on their anterior surface, occupying the whole circumference of the jaws; but there are also scapular teeth on the margins of the jaws. 1. E. haleyon. 2. E. Fausti.

GENUS XIX. ANENCHELUM. Body much elongated, or cel-shaped. Head obtuse; jaws armed with strong teeth. Dorsals continuous; ventrals consist of some long rays. Vertebre long and slender; apophysary bonelets are fastened to the apophyses. 1. A. Glaristanum. 2. A. isopleurum. 3. A. dorsale. 4. A. heteropleurum. 5. A. latum. 6. A. longipinne. GENUS XX. NEMOPTERYX. Body elongated. Caudal fin rounded; pectorals very large. Strong teeth in the jaws. Vertebra robust.

1. N. crassus. 2. N. elongatus.

GENUS XXI. XIPHOPTERUS. Body very long. Tail deeply forked. Ventrals thoracic; anal extends to nearly two-thirds of the length of the fish. Head small. Ribs long, and interlaced with the sternal appendages, as in Clupea.

1. X. falcatus.

GENUS XXII. PALEORHYNCHUM. Body much elongated, or anguilliform. Head small. Jaws equal, and drawn out into a very long slender beak, without teeth. Dorsal and anal much developed; caudal fin little forked. Apophysial bonelets disposed in pairs.

1. P. longirostre. 2. P. Egerioni. 3. P. Glarissanum. 4. P. latum. 5. P. medium. 6. P. Colei. 7. P. microspondylum.

GENUS XXIII. HEMIRHYNCHUS. Body elongated. Upper jaw drawn out into a slender beak, without teeth. Scales large. Skeleton feeble; spinous apophyses slender; interapophysial bonelets disposed in pairs.

1. H. Des Hayes.

FAMILY II.—XIPHOIDEI.

This remarkable family has but few fossil representatives. Body elongated; scales small; upper jaw lengthened into a thin beak. Ventrals thoracic. Teeth scapular. Vertebrae long, surmounted by apophyses in the form of vertical plates. Articular apophyses large.

GENUS I. TETRAPTERUS. Body elongated. Beak very prominent. Teeth scapular. Scales long and thin. Dorsal commences at the nape. Ventrals thoracic. Vertebrae very narrow in the middle.

1. T. priscus. 2. T. minor.

GENUS II. COLOPHYNCHUS. Beak extremely slender and straight, diminishing very gradually, and having a cavity extending to its point.

1. C. rectus. 2. C. sinuatus.

FAMILY III.—SPHYRENOIDEI.

Body elongated. Scales large. Jaws with long cutting teeth. Dorsals separated. Ventrals abdominal. Vertebrae few.

GENUS I. SPHYRENA. Body slender. Head lengthened. Intermaxillary, palatal, and lower-jaw teeth strong and cutting. Spinous dorsal separated from the soft fin. Scales of middle size. Vertebrae few and long.

1. S. folcensis. 2. S. gracilis. 3. S. Amici. 4. S. maxima.

GENUS II. SPHYRENODUS. Jaws with very strong but uniform teeth, conic, and slightly compressed.

1. S. priscus.

GENUS III. HYPSODON. Seems to have been very large. Jaw very thick, and teeth formidable; those of the upper jaw placed in several rows.

1. H. Lewisianus. 2. H. tellapleus. 3. H. oblongus.

GENUS IV. SAUROCEPHALUS. Teeth straight, very compressed, and furnished with vertical plicae.

1. S. lanceolatus. 2. S. striatus.

GENUS V. SAURODON. Teeth narrower than in the last genus, compressed, oblique on their summit, and striated at their base.

1. S. Leanus.

GENUS VI. CLADOCYCLUS. Tube on the scales of the lateral line branched.

1. C. Lewisianus. 2. C. Gardineri.

GENUS VII. RHAMPHOGNATHUS. Body elongated. Ventrals abdominal. Jaws very slender, with the upper overlapping the lower.

1. Rh. paralepidotes.

GENUS VIII. MESOGASTER. Body elongated. Head short, obtuse. Jaws equal. Ventrals abdominal.

1. M. sphyremonoides.

FAMILY IV.—BLENOIDEI.

Body squat; size generally small. Scales small. Ventrals jugular; one very long dorsal fin, partly consisting of cyprinoid spines and soft rays. Teeth more or less conspicuous.

GENUS I. SPINACANTHUS. First dorsal consists of enormous spines, equalling in length the body of the fish; and the anterior spines are dentate at their base; second dorsal slender.

1. S. blennoides.

FAMILY V.—LOPHIOIDEI.

Pectorals supported on a prolongation of the carpal bones, which form as it were an arm. Ventrals thoracic. Scales entirely wanting or replaced by osseous tubercles, or short spines. Head very large; jaws armed with numerous sharp teeth, in suborbital bones.

GENUS I. LOPHIUS. Head enormous, depressed; mouth immense. Two dorsals, the first of which extends to the head.

1. L. brachysomus.

FAMILY VI.—LABROIDEI.

Form oblong; body scaly. A single dorsal sustained anteriorly by spinous rays. Jaws covered by fleshy lips. No palatal teeth; but they are found on the three pharyngeal bones, either as plates or pointed teeth.

GENUS I. LABRUS. Form squat. Skeleton massive. Opercular pieces without spines or dentations.

1. L. Valenciennesii. 2. L. Ibbetsoni.

DIVISION II.—CYCLOIDEI MALACOPTERYGEI.

FAMILY VII.—CYPRINOIDEI.

Body oblong. Ventrals abdominal. Inferior pharyngeal bone armed with several rows of strong teeth, sometimes conical, sometimes compressed, or crooked; no jaw teeth; mouth small, with fleshy lips, often carrying beards. Vertebrae strong and few; three branchiostegous rays. The family are chiefly fresh-water fishes.

GENUS I. ACANTHOPSIS. Form very long, and compressed. Caudal fin truncated and rounded; dorsal placed a little before the ventrals. Beards short. First suborbital bone mobile, bifurcated, and terminating in sharp points. Scales scarcely perceptible.

1. A. angustus.

GENUS II. CORVIS. Form elongated, cylindrical. Cheeks smooth. Orbiculars immovable, concealed under the skin. Scales small. Pharyngeal teeth slender, bevelled.

1. C. centraochir. 2. C. cephalotes. 3. C. longiceps.

GENUS III. GONIO. Form cylindrical. Dorsals opposite to two ventrals, with a large simple ray. Scales of medium size, and very thin.

1. G. ansalis.

GENUS IV. TINCA. Form squat. Fins thick. Scales small. A single row of pharyngeal teeth, claviform. Large rounded fins, with very thick rays.

1. T. furnieri. 2. T. leptosoma. 3. T. micropygoptera.

GENUS V. LEUCISCUS. Body fusiform, covered with large scales. Pharyngeal teeth in two rows. Skeleton robust.

1. L. Oningensis. 2. L. latusoculus. 3. L. padulus. 4. L. heterurus. 5. L. leptus. 6. L. macruscus. 7. L. papryraceus. 8. L. cephalon. 9. L. gracilis. 10. L. Hartmanni. 11. L. brevis.

GENUS VI. APSIS. Body elongated, compressed, covered with large scales, salient at their posterior margin. Mouth oblique; inferior jaw reaching beyond the upper; pharyngeal teeth long, in two rows. Dorsal behind the ventrals; caudal much forked. Skeleton slender.

1. A. gracilis. 2. A. Brongniartii. GENUS VII. RHODEUS. Form squat, compressed, covered with large, thin scales. No beards. Pharyngeal teeth bevelled. Dorsal opposite to anal; caudal forked; all the fins small. Fishes all very small.

1. Rh. elongata. 2. Rh. latier.

GENUS VIII. CYCLURUS. Dorsal and anal large; caudal rounded. Vertebra column recurved at its extremity. Vertebrae thick and short. Scales thick and long.

1. C. Valenciennesii. 2. C. minor.

FAMILY VIII.—CYPRINODONTES.

Form very regularly oblong. Scales large, though the fishes are small. Ventra abdominal. Teeth in both jaws. More than three branchiostegous rays.

GENUS I. LESBIAS. Body rather elongated. Jaws horizontally flattened, and furnished with serrated teeth. Opercula large. Many branchiostegous rays. Dorsal opposite to the anal.

1. L. cephalotes. 2. L. persimilis. 3. L. gobio. 4. L. Meyeri. 5. L. crassicaudatus.

FAMILY IX.—ESOCIDEI.

Body slender, with large scales. Superior maxillaries without teeth, and placed in a line with the intermaxillaries. Teeth generally very strong, and conical in the lower jaw, palatines, and vomer.

GENUS I. ESOX. Form long, cylindrical. Head large; muzzle long, obtuse, depressed; mouth very wide. Palatine teeth very strong and conical, as are those on the anterior part of the vomer, and on the lower jaw; small teeth on the intermaxillaries; none on the maxillaries. Numerous branchiostegous rays. Dorsal and anal approximate to the caudal, which last is a little sloped. Scales large. Skeleton not robust.

1. E. Otto. 2. E. lepidotus.

GENUS II. HOLOSTEUS. Form very elongated. Skeleton slender; ribs very thin; muscular apophyses numerous and very large.

1. H. Escelus.

GENUS III. SPHENOLEPIS. Form elongated. Dorsal opposite to ventrals; caudal scarcely forked. Scales large.

1. Sph. squamosus. 2. Sph. Cuvieri.

GENUS IV. ISTius. Body elongated. Dorsal stretching along almost the whole back; anal very far back. Scales large. Vertebrae very short; spinous apophyses very close together, and more numerous than the apophyseal bonelets. Small teeth in the jaws.

1. I. grandis. 2. I. macrocephalus. 3. I. microcephalus. 4. I. gracilis.

FAMILY X.—HALECOIDEI.

This family includes the Clupeae and Salmones. The fish are very symmetrical, and covered with well-defined scales. Ventra abdominal. Superior maxillaries forming partially the margin of the jaw, often carry teeth, which are conical, and more or less conspicuous. Skeleton slender, with or without sternal ribs. Size from small to medium.

GENUS I. MALLOTUS. Body elongated. Skeleton slender. Dorsal in the middle of the back; anal very large. Teeth scapular.

1. M. villosus.

GENUS II. OSMERUS. Body elongated. Dorsal opposite to ventrals. Teeth strong and conical, in the palatines and maxillaries.

1. O. Cordieri. 2. O. Glarisianus.

GENUS III. OSMEROIDES. Dorsal far forwards. Head flat; mouth rather small. No sternal ribs.

1. O. Monasteri. 2. O. microcephalus. 3. O. Lewesiensis. 4. O. granulatus.

GENUS IV. ACROGNATHUS. Head large, flat, and broad; 1. A. boops.

GENUS V. AUROLEPIS. Form approaching to that of Salmo. Head high; muzzle pointed; jaws of equal length. Vertebrae higher than long. Pectorals have long slender rays. Scales large, subangular.

1. A. typus.

GENUS VI. ALOSA. Form symmetrical. Vertebrae very numerous; ribs sternal. A notch in the middle of the upper jaw.

1. A. elongata.

GENUS VII. MEGALOPS. Resembles alosa; but has a very large eye. Last dorsal terminates in a filament.

1. M. priscus.

GENUS VIII. CLUPEA. Form symmetrical. No notch in the middle of the upper jaw. Sternal ribs. Dorsal in the centre of the back.

1. C. macroceps. 2. C. dentex. 3. C. Beurrardi. 4. C. brevisima. 5. C. lata. 6. C. brevis. 7. C. temasilus. 8. C. milnii. 9. C. megalepis. 10. C. Sheoscheri. 11. C. leptostes. 12. C. minuta. 13. C. Goldfussi. 14. C. cataphrygoptera.

GENUS IX. ENGRAULIS. Body elongated. Mouth very wide; muzzle pointed, and projecting beyond the lower jaw. Pectorals very large; dorsal opposite to the ventrals. No sternal ribs.

1. E. evolans.

GENUS X. HALEC. Head very broad and flat. Mouth very wide. Lower jaw-bone very narrow. No sternal ribs.

1. H. Sternbergii.

GENUS XI. PLATINX. Form elongated. Dorsal placed far back; pectorals very long. Vertebra column very stout. No sternal ribs.

1. P. elongatus. 2. P. gigas.

GENUS XII. COLOGASTER. Allied to Platinx, but has an extended anal fin. Belly appears hollowed.

1. C. analis.

GENUS XIII. NOLEUS. Body squat. Dorsal extends over most of the ridge of the back; ventrals abdominal; caudal rounded. Vertebrae higher than long.

1. N. laticaudatus.

FAMILY XI.—ANGUILLIFORMES.

Body uniformly and greatly elongated. Scales very minute. No ventrals, and sometimes no pectorals. Teeth small, conical, and generally strong.

GENUS I. ANGUILLA. Pectorals near the gills, which open on each side of the fins; dorsal commences at a certain distance from the nape.

1. A. latissima. 2. A. ventralis. 3. A. brevicauda. 4. A. multiradiata. 5. A. paucura. 6. A. branchiostegalis. 7. A. interspinalis. 8. A. leptoptera.

GENUS II. ENCHYTOPOUS. Body much elongated. Dorsal prolonged to the nape. Thoracic cincture very slender.

1. E. tigrinus.

GENUS III. SPEAGEBRANCHUS. Gill-covers approximate under the throat. Vertical fins placed far back. Muzzle pointed.

1. Sph. formosissimus.

GENUS IV. OPHICURUS. Differs from Anguilla in having the termination of the dorsal and anal fins before reaching the end of the tail, which is thus finless, and terminates in a point.

1. O. aculeatus.

GENUS V. LEPTOCEPHALUS. Differs from Anguilla in having the gill-openings before the pectorals, and in having much more of the ribbon form. Head extremely small, and muzzle pointed. Pectorals scarcely perceptible.

1. L. gracilis. 2. L. medius. GEOLOGICAL FORMATIONS IN WHICH FOSSIL FISHES ARE FOUND.

ORDER I.—GANOIDS.

Family of Lepidoids.

I. IN THE DEVONIAN OR OLD RED FORMATION.

Catopterus macrolepidotus, Caithness, Widell. Osteolepis macrolepidota, Cromarty, Caithness, Orkney. " microlepidotus, Caithness, Orkney. " acanthodes, Caithness in geodes. " major, Lethen-bar. Acanthodes pusillus, Gordon Castle. Diplacanthus striatus, Cromarty. " striatus, Lethen-bar. " longispinus, Lethen-bar, Cromarty. " crassispinus, Caithness. Chelracanthus Murchisoni, Gamrie. " microlepidota, Lethen-bar, Cromarty. " minor, Orkney. Cheirolepis Tralli, Orkney. " uragus, Gamrie. " Cumingi, Lethen-bar, Cromarty. Cephalaspis Lyelli, Howden, Brecon, Whitbach. " serrata, Whitbach. " Lewisii, Whitbach. " Lloydii, Whitbach, Wales. Pterichthys Milleri, Cromarty. " productus, Lethen-bar. " latus, Lethen-bar. " cornutus, Lethen-bar. " testudinarius, Lethen-bar. " oblongus, Cromarty, Gamrie. " cancriformis, Orkney. " hydrophilus, Denwood, Fifeshire. Coccoctenus decipiens, Orkney, Caithness. " oblongus, Lethen-bar. " cuspidatus, Cromarty, Gamrie.

II. COAL FORMATION.

Acanthodes Broomii, Saarbrück. " sulcatus, Newhaven near Edinburgh. Amblypterus macropterus, Saarbrück. " eupterygius, Saarbrück, Lebach. " latu, Saarbrück, Lebach, St Ingbert. " lateralis, Saarbrück, Lebach. " nemopterus, Newhaven, Inchkiln. " pachycephalus, Gamrie. " striatus, Newhaven. Palaeoniscus fultus, Massachusetts, Connecticut. " Agassizii, New Jersey. " macropterus, Massachusetts. " Egertonii, Staffordshire. " Monensis, Anglesey. Duvernoyi, Appel by Kreutznach. " minutus, Appel by Kreutznach. " Blainvillei, Muse by Autun. " Voltzii, Muse by Autun. " angustus, Muse by Autun. " Robustii, Burdeshouse by Edinburgh. " striolatus, Burdeshouse by Edinburgh. " ornatus, Burdeshouse in Fifeshire. " carinatus, Newhaven. " Vratislavensis, Suppersdorf, Bohemia. " lepidurus, Scharfenbeck, Bohemia. Catopterus gracilis, Connecticut. " parvulus, New Jersey. " anguilliformis, Connecticut. Eurynotus crenatus, Burdeshouse. " fimbriatus, Newhaven. " tenuiceps, Massachusetts. Platycephalus cervulus, Leeds. Gyroplepis Rankeni, Leeds. Pleurolepis rugosus, Carlisle.

III. ZECHSTEIN, OR MAGNESIAN LIMESTONE FORMATION.

Amblypterus Offersii, Ceara in Brazil. Palaeoniscus Freislebeni, Mansfeld, Hesse. Palaeoniscus magnus, Mansfeld, Hesse.

IV. TRIAS, OR VARIGATED SANDSTONE, MUSCHELKALK, AND KEUPER.

Palaeoniscus catopterus, var. sandstone of Tyrol. Amblypterus Agassizii, muschelkalk of Thuringia. Gyroplepis Alberti, muschelkalk of Schwanningen, Landeck. " tenulistrata, muschelkalk of Schwanningen, Aixmouth. " maximus, muschelkalk of Landeck, Wickwar.

V. JURASSIC FORMATION.

a. Lias.

Dapedius politus, Lyme Regis. " granulatus, Lyme Regis. " punctatus, Lyme Regis. " Colei, Lyme Regis. " orbis, Whitby. " arenatus, Lyme Regis. " micans, Whitby. Tetragonolepis semicinctus, Bronn, Neidlingen. " confusus, Lyme Regis. " speckatus, Lyme Regis. " pustulatus, Lyme Regis. " radiatus, Lyme Regis. " leiosomus, Lyme Regis. " Leachii, Lyme Regis. " heterodera, Lyme Regis, Wurttemberg. " pholidotus, Boll, England. " ovalis, Boll, England. Bovier Seefeld. " dorsalis, Newcastle. " mollifier, Banwell, Whitby. " angulifer, Stratford-on-Avon. " striatus, Whitby. Amblyurus macrostomus, Lyme Regis. Semionotus Leptocephalus, Boll. " Bergeri, Koberg. " latus, Seefeld. " rhombifer, Lyme Regis. " Nilssonii, Scania. " striatus, Seefeld. Centrolepis asper, France, Germany, England. Lepidotus gigas, Lyme Regis. " semiherratus, Whitby, Scarborough. " undatus, Lyme Regis. " rugosus, Lyme Regis, Whitby. " fimbriatus, Lyme Regis, Haring in Tyrol, Coburg. " ornatus, Seefeld. " frondosus, Zell near Boll. " speciosus, Seefeld. " parrulus, Seefeld. " serrulatus, Whitby. " pectinatus, Whitby. Pholidophorus Becheli, Lyme Regis. " onychius, Lyme Regis, Chernock. " dorsalis, Seefeld. " limbatus, Lyme Regis. " Sirichthys, Whitby. " Hastingsii, Whitby. " latissimus, Seefeld. " pusillus, Seefeld. " furcatus, Seefeld. " leptcephalus, Street. " pachycomus, Lyme Regis. " crecularius, Lyme Regis. " Hartmanni, Ohmiden. Nothosomus octostylus, Street. FOSSIL ICHTHYOLOGY.

Family of Sauroids.

I. DEVONIAN, OR OLD RED FORMATION.

Diplopterus affinis, Gamrie. Agassizii v. borealis, Orkney. macrocephalus, Lethen-bar, Frintscha.

Platygnathus ancidentis, Calthness. Jamesoni, Dura-den. minor, Dura-den.

Dendrodus latus, Morayshire. strigatus, Morayshire, Riga. sigmoides, Morayshire.

Lammodus biporcatus, Morayshire, Riga. Panderi, Morayshire, Riga.

Crolodus incurvis, Morayshire, Riga. Megalichthys priscus, Orkney.

II. COAL FORMATION.

Pygopterus Bonnardi, Muse near Autun. Bucklandi, Burdichouse. Inclus, Saarbrück. Jamesoni, Burdichouse. Greenochii, Newhaven.

III. ZECHSTEIN, OR MAGNESIAN LIMESTONE FORMATION.

Pygopterus Humboldti, Mansfeld, Niederhawen, Rigglesdorf, &c. mandibularis, calc. magn. of East Tricksey, Terryhill. sculptus, calc. magn. of East Tricksey, Terryhill. Acrolepis Sedgewickii, calc. magn. of East Tricksey, Terryhill. asper, Mansfeld.

IV. TRIAS FORMATION.

Sauroichthys apicalis, Lainzck, Benk, Göttingen, Hildesheim, Jena, bonedbed at Axmouth; muschelkalk at Bareuth. Mogotus, muschelkalk at Lunville, Bareuth. acuminate, bonedbed at Austell. longidens, bonedbed at Austell, Pyton-on-Severn. semicostatus, muschelkalk of Benk, Lainzck, Saxony. Hanover. tennifrons, muschelkalk of Bavaria. costatus, muschelkalk of Benk, Lainzck, Bareuth. augustus, muschelkalk.

V. JURA FORMATION.

a. Lias.

Eugnathus chirotis, Lyme Regis. orthostomus, Lyme Regis. Philopteris, Lyme Regis. misor, Lyme Regis. opercularis, Lyme Regis. polyodon, Lyme Regis. speciosus, Lyme Regis. fasciculatus, Whitby. leptosus, Lyme Regis. medullaris, Lyme Regis. ornatus, Lyme Regis. scabrioculatus, Lyme Regis. tennidae, Street. giganteus, lias of Boll.

Ptycholepis Bollensis, lias of Boll, Lyme Regis, Whitby. Conodus ferox, Lyme Regis.

Pachycormus macropterus, lias of Burgundy. acutirostris, Whitby. cartus, Whitby. gracilis, Whitby, Wurtemberg. biferurus, Lyme Regis. latirostris, Lyme Regis. latirostris, Whitby. latus, Whitby. macrurus, Lyme Regis. leptosteus, Lyme Regis.

Caturus Bucklandi, Lyme Regis. Meyeri, black schist of Western Rawensberg. Thrissonotus Colei, Lyme Regis. Sauropis latus, Lyme Regis, Wurtemberg, Baden. Leptolepis Bromili, Lyme Regis, Neidinger, Bareuth, Caen, Baden, Oberland. Jageri, lias of Boll. longipes, lias of Boll. canaliculatus, Lyme Regis. tenellus, lias of Baden. filipennis, Street.

Aspidorhynchus Anglicus, Whitby. Walchneri, Baden, Oberland. Belonostomus acutus, Whitby. Anningin, Lyme Regis. Saurostomus esocinus, Baden, Oberland. (nondescriptus), Lincolnshire.

b. JURASSIC PROPER.

Eugnathus microlepidotus, calc. of Solenhofen. Pachycormus macroponus, Vaches Noires in Normandy. Caturus furcatus, calc. of Solenhofen. pachyurus, calc. of Solenhofen. macrurus, calc. of Solenhofen. maximus, calc. of Solenhofen. microchirus, calc. of Solenhofen. branchiostegus, calc. of Solenhofen. FOSSIL ICHTHYOLOGY.

Ganoids. Caturus latus, calc. of Solenhofen. " elongatus, calc. of Solenhofen. " macrodus, calc. of Solenhofen. " pleiodus, colite of Stonesfield. " angustus, Portland-stone of Garstington. Amblyseius gravis, colite of Northampton. Sauropis lemniana, calc. of Solenhofen. " paradoxa, calc. of Stonesfield. Thrissops formosus, calc. of Kehlheim. " cephalus, calc. of Solenhofen. " micropodus (locality unknown). " intermedius, Upper Jura of Wethern. " salmoensis, calc. of Kehlheim and Solenhofen. " subovatus, calc. of Kehlheim and Solenhofen. " mesogaster, calc. of Solenhofen. Leptolepis sprattiformis, schistos of Pappenheim and Solenhofen. " Voithii, calc. of Kehlheim. " crassus, calc. of Solenhofen. " macrocephalus, calc. of Solenhofen. " polypondylus, calc. of Solenhofen. " Knorrii, calc. of Solenhofen. " dubius, calc. of Solenhofen. " contractus, calc. of Solenhofen. " latus, calc. of Eichstatt. " pandispodylus, calc. of Kehlheim. " pusillus, calc. of Kehlheim. " macrophthalmus, Oxford clay of Chippenham. Aspidorhynchus scutirostris, calc. of Solenhofen. " speciosus, calc. of Kehlheim. " ornatus, calc. of Kehlheim. " macrolepidotus, calc. of Eichstatt. " lepturus, calc. of Kehlheim. " quadus, Oxford clay of Chippenham. Belonostomus sphyraenoides, calc. of Solenhofen. " Münsteri, lithographic-stone of Bavaria. " temnurostris, calc. of Solenhofen. " subulatus, calc. of Solenhofen. " ventralis, calc. of Solenhofen. " Kochii, calc. of Kehlheim. " leptosteus, colite of Stonesfield. " brachysomus, calc. of Solenhofen. Megalurus lepidotus, calc. of Solenhofen. " brevirostratus, calc. of Kehlheim. " elongatus, calc. of Kehlheim. " larvus, calc. of Kehlheim. Macrosemium rostratum, calc. of Solenhofen. " brevirostris, colite of Stonesfield.

VI. Chalk Formation. Caturus, chalk of Kent and Lewes. Aspidorhynchus Comptoni, South America. Belonostomus cinctus, Lowes.

Family of Calocanthus.

I. Devonian, or Old Red Formation. Holoptichthys gigantus, Elgin, Clashbennie, Gamrie, Glammis. " Flemingii, Dura-den, St Petersburg. " nobilissimus, Elgin, Clashbennie, Frintscha. " Andersoni, Dura-den. " Murchisoni, Clashbennie. " Osmanusli, Liége, Namur, Eifel. Actinolepis tuberculatus, Elgin, St Petersburg. Platygnathus Jamesoni, Dura-den, St Petersburg. " paucidens, Pemonia in Orkney. Glyptosterus favosus, Clashbennie, Elgin, St Petersburg, Ladoga, &c. " reticulatus, erraticus, Elgin, Nairn, Ladoga, &c. Phyllolepis cyclopleura, Clashbennie. Glyptolepis leptopterus, Elgin, Lethen-bar, St Petersburg. " microlepidotus, Lethen-bar. " elegans, Gamrie. Dendrodes latus, Findhorn in Moray, Riga. " striatus, Elgin, Riga, St Petersburg. " sigmoides, Elgin, St Petersburg. " tenuistratus, St Petersburg. " minor, Megra. Lamnodus apoplatyus, Elgin, Riga, Cremona, St Petersburg. " Pudert, Elgin, Riga, Cremona, St Petersburg. " saliens, Elgin. Cricodon incurvus, Elgin, Riga. Asterolepis Armatus, Riga, Megra. " ornata, Riga, Megra. " species, Voronble.

II. Coal Formation. Holoptichthys Hibberti, Burdleighouse. " sauroides, Burdleighouse. " falcatus, Greenside by Glasgow. " Porlocki, Ireland. " Garneri, Lanesfield. " granulatus, Manchester. " striatus, Great Junction near Edinburgh. " lacustris, North Stafford. Cetacanthus Phillippii, Halifax. " lepturus, Leeds, Manchester. " Münsteri, Lebach in Bavaria. Phyllolepis temnurostrus, Burdleighouse. Hoploplegus Binneyi, Manchester. Uromenus lobatus, Burdleighouse.

III.—Zechstein Formation. Calacanthus granulatus, magnes, calc. of Durham, E. Trickey. " gracilis, England.

IV.—Trias Formation. Calacanthus minor, muschelkalk of Lunéville.

V.—Jurassic and Oolite Formation. Undina striolaris, lithographic-stone of Bavaria. " Kobleri, lithographic-stone of Bavaria. Ctenolepis cyclus, colite of Stonesfield. Gyrosteus mirabilis, lias of Whitby and Lyme Regis.

VI.—Chalk Formation. Macropoma Mantelli, chalk of Lewes, Sussex, Cambridge, Chirnay. " Egerton, gault of Specion.

Family of Pyrnodonts.

I.—Zechstein Formation. Globulodus elegans, Zechstein of Germany.

II.—Trias Formation. Pycnodus priscus, Keuper, Tubingen-Württemberg. Sphyrodus annularis, Keuper, Tubingen-Württemberg. " minimus, coroplite-breccia of Tubingen-Württemberg. Placodus gigas, muschelkalk of Bamberg, Lunéville. " Andriani, muschelkalk of Bamberg, Lunéville. " Münsteri, muschelkalk of Bamberg in Bavaria, and of Eppingen in Thuringia. " rostratus, muschelkalk of Lainzick. " impressus, variegated sandstone of Deux-Ponts. Colobodus Hogardi, muschelkalk of Lunéville.

III.—Jurassic Formation. c. Liass. Sphyrodus microdon, Lyme Regis. b. Jura Proper. Pycnodus rhombus, Torre d'Orlando. gigas, Portland-stone of Switzerland and Germany. Nicoleli, Portland-stone of Neufchâtel. Bucklandi, calc. of Stonesfield. didymus, calc. of Stonesfield. rugulosus, sandstone of Northamptonshire. umbonatus, forest marble. ovalis, Stonesfield slate. Hugii, Portland-stone of Soleure. Mandelli, forest marble of Tilgate. latirostris, colite of Stonesfield. obtusus, colite of Stonesfield. parvus, colite of Stonesfield. tristychus, colite of Stonesfield. biseriatus, colite of Little Gibraltar near Bedford. trigonus, colite of Stonesfield. FOSSIL ICHTHYOLOGY.

Ganoïds. Pycnodus latidens, Portland-stone of Soleure. Pygno- donts. discoides, colite of Little Gibraltar near Bedford. " graellis, coral-rag of Hildesheim and Lindenberg, Hanover. " minutus, coral-rag of Hildesheim and Lindenberg, Hanover.

Gyronchus oblongus, calc. of Stonesfield. Spheronodus subovatus, lithographic-stone of Solenhofen. Microdon elegans, calc. of Solenhofen. " bennettii, calc. of Solenhofen. " analis, calc. of Solenhofen. " radiatus, calc. of Purbeck. " abdominalis, calc. of Solenhofen. " platyrus, calc. of Solenhofen. Spheronodus gigas, Kimmeridge clay. " minor, Stonesfield clay. Gyrodon macropthalmus, calc. of Kehlheim. " frontatus, calc. of Kehlheim. " rugosus, calc. of Kehlheim. " umbilicus, colite of Durrheim in Germany. Jurassicus, Portland-stone of Soleure. Cuvieri, Boulogne, Weymouth. " trigonus, colite of Malton. " trigonus, calc. of Stonesfield. " radiatus, calc. of Caen. " Mantelli, calc. of Tilgate. " gracilis, calc. of Kehlheim. " analis, calc. of Kehlheim. " efrcularis, calc. of Solenhofen. " platyrus, calc. of Solenhofen. " punctatissimus, calc. of Kehlheim. " rhomboidalis, calc. of Kehlheim. " macropterus, calc. of Kehlheim. " perlatus, calc. of Stonesfield. " gibbosus, calc. of Kehlheim.

IV.—Chalk Formation.

Pycnodus Münsteri, greensand of Ratisbon. " complanatus, greensand of Ratisbon. " subclavatus, chalk of Mastricht. " cretaceus, chalk of Kent. " angustus, chalk of Kent. " elongatus, chalk of Kent. " marginalis, chalk of Kent. " Couloni, yellowstone of Neufchâtel. " minor, Speeton clay. Acrotemnus fabe, chalk of Kent. Spheronodus crassus, chalk of Maestricht. " mitrula, greensand of Ratisbon. " Neocomensis, yellowstone of Neufchâtel. Gyrodon cretaceus, chalk of Lewes. " angustus, chalk of Maidstone. " rugulosus, greensand of Ratisbon. " Münsteri, greensand of Ratisbon. " minor, Speeton clay. " mammillaris, chalk of Kent.

V. Limestone of Monte Bolca.

Pycnodus platessus, Monte Bolca. " orbicularis, Monte Bolca.

VI.—Tertiary Formation.

Pycnodus tollapicus, London clay of Sheepy. Periodus Königii, London clay of Sheepy. Spheronodus lens, tertiary beds of Osnabruck. " integerrimus, tertiary beds of Pflenzengen. " parus, tertiary beds of Cassel. " cinctus, calc. groser of Styria. " truncatus, tertiary beds of Osnabruck. Gyrodon bivior, London clay of Sheepy. Phyllodus tollapicus, London clay of Sheepy. " planus, London clay of Sheepy. " polyodus, London clay of Sheepy. " marginalis, London clay of Sheepy. " irregularis, London clay of Sheepy. " medius, London clay of Sheepy. Pisodon Owenii, London clay of Sheepy.

Species of which the Geological Position is Doubtful.

Spheronodus depressus, Salzburg. " discus, Algarves in Portugal. Spheronodus conicus, Ceylon. " oculus serpentinus, Algarves. Gyrodon runcinatus, (1)

Family of Sclerodermes.

I.—Chalk Formation.

Acanthoderma ovale, Glaris. " spinosum, Glaris. Acanthopleurus aculeatus, Glaris. " brevis, Glaris. Dercetis elongatus, Lewes. " scutatus, Westphalia.

II.—Limestone of Monte Bolca.

Blochius longirostris, Monte Bolca. Rhinellus nasalis, Monte Bolca. Ostracion microrus, Monte Bolca.

III.—Tertiary Formation.

Glyptocephalus radiatus, London clay of Sheepy. Doubtful.

Rhinellus furcatus, Mount Lebanon.

Family of Gymnodonts.

Diodon tenuispinus, Monte Bolca. " Scilla, Monte Bolca (?) " Erinaceus, Monte Bolca (?)

Family of Lophabranchiates.

Calomostoma brevissculum, Monte Bolca. Synagathus opisthopterus, Monte Bolca.

Family of Acipenserids.

Acipenser tollapicus, London clay of Sheepy. Chondrostena acipenseroides, lias of Lyme Regis.

Order II.—PLACOÏDS.

I.—Silurian Formation.

Onchus, Murchisoni, Ludlow. " temnistratus, Ludlow.

II.—Devonian Formation.

Onchus arcuatus, Bromyard. " semistratus, Southstone rock. Ctenacanthus ornatus, Wales. " serratus, Kohlhusen. Ptychacanthus dubius, Abergavenny. Ctenoptychus cretatus, Meaga, Russia. " priscus, Scotland.

III.—Coal Formation.

Oracanthus Milleri, calc.-carbon of Bristol. " frustulosus, calc.-carbon of Bristol. " minor, calc.-carbon of Bristol. " confusus, calc.-carbon of Armagh. Onchus salatus, calc.-carbon of Bristol. " hamatus, calc.-carbon of Bristol. " reticulatus, calc.-carbon of Armagh. " plicatus, calc.-carbon of Armagh. " falcatus, calc.-carbon of Armagh. " subulatus, coal, Rhubon, Wales. Ctenacanthus major, calc.-carbon of Bristol. " temnistratus, calc.-carbon of Bristol. " brevis, calc.-carbon of Bristol. " heterogyrus, calc.-carbon of Armagh. " arcuatus, calc.-carbon of Armagh. " crenulatus, calc.-carbon of Armagh. Gyracanthus formosus, calc.-carbon of Burdiehouse, Newcastle, Sunderland, Alnwick, Burntisland, tuberculatus, Sunderland. Alnwickiensis, Alnwick, England. " ornatus, coal schists of Wales. Sphenacanthus serratus, Burdiehouse. Tristychnus arenatus, Greenside near Glasgow. Orodus cinctus, calc.-carbon of Bristol. " ramous, calc.-carbon of Bristol. Ctenoptychus apicalis, coal schists Stafford, Manchester. " pectinatus, Burdiehouse, Manchester. " denticulatus, Burdiehouse, Manchester. " cuspidatus, coal of Glasgow. FOSSIL ICHTHYOLOGY.

Placoids. Ctenoptichthys dentatus, calc.-carbon of Armagh. " serratus, calc.-carbon of Armagh. " macrodus, calc.-carbon of Armagh. " crenatus, coal, Carlake. Helodus simplex, coal schist of Stafford, Coalbrookdale. " levisimus, calc.-carbon of Bristol. " subtenuis, calc.-carbon of Bristol. " gibberulus, calc.-carbon of Bristol. " tergoides, calc.-carbon of Bristol. " mitratus, coal, Carlake. " didymus, calc.-carbon of Armagh. " mammillaris, calc.-carbon of Armagh. " planus, calc.-carbon of Armagh. Chomatodus truncatus, calc.-carbon of Armagh. " cinctus, calc.-carbon of Bristol. " linearis, calc.-carbon of Bristol. Pasmodes rugosus, calc.-carbon of Bristol, Esky, Geroldstein. " porous, calc.-carbon of Bristol. Cochliodus elongatus, calc.-carbon of Bristol, Armagh, Clifton. " magnum, calc.-carbon of Armagh. " oblongus, calc.-carbon of Armagh. " acutus, calc.-carbon of Armagh. " striatus, calc.-carbon of Armagh. Prestodus Jonesii, calc.-carbon of Armagh. " parallelus, calc.-carbon of Armagh. " transversus, calc.-carbon of Armagh. " obliquus, calc.-carbon of Armagh, Carlake. " subulavis, calc.-carbon of Armagh. " angustus, coal, Carlake. Pleurodus affinis, coal schist, Rhuban, Carlake. " Rankinei, coal, Carlake. Ctenodus catenatus, coal, Tynemouth. " striatus, calc., Ardwick. Petalodus acuminate, calc.-carbon of Durham, Yorkshire, Glasgow. " Hastingsiae, calc.-carbon of Armagh. " pittacinus, calc.-carbon of Armagh. " levisimus, calc.-carbon of Armagh. " rectus, calc.-carbon of Armagh. " radicans, calc.-carbon of Armagh. " marginalis, calc.-carbon of Armagh. " sagittatus, calc.-carbon of Armagh. Cladodus mirabilis, calc.-carbon of Armagh. " striatus, calc.-carbon of Armagh. " marginitans, calc.-carbon of Armagh. " Milleri, calc.-carbon of Bristol. " conicus, calc.-carbon of Bristol. " acutus, calc.-carbon of Laugbgal. " Hibberti, Burdleighouse. " parvus, Burdleighouse. Diplodus gibbosus, coal, Carlake. " minutus, Burdleighouse. Carcharopis prototypus, calc.-carbon of Yorkshire, Armagh.

IV.—Zechstein Formation.

Gyroptristis obliquus, magn. linest. of Belfast. Hybodus major, muschelkalk of Lunéville, Bareuth, Breslau. " tenius, muschelkalk of Lunéville, Bareuth. " dimidatus, muschelkalks of Lunéville. " minor, bonebed of Bristol. Leiacanthus falcatus, muschelkalk of Lunéville, Bareuth. Nemacanthus moulliffer, bonebed of Westbury. " filifer, bonebed of Leineh. " granulosus, muschelkalk of Leineh. " sellcicous, muschelkalk of Leineh. Hybodus pilosilla, muschelkalk of Schwennenigen, Tubingen, Tar- nowitz, Lunéville. " Mongostii, muschelkalk of Schwennenigen, Lunéville. " angustus, muschelkalk of Lunéville. " longiconus, muschelkalk of Lunéville, Gisement. " obliquus, muschelkalk of Voges. " polygyrus, muschelkalk of Lunéville. " minor, bonebed of Bristol. " cuspidatus, Keuper, Tubingen, Rietheim. " sublevis, Keuper, Tubingen. " apicalis, Keuper, Hildesheim. Strophodon ornatus, muschelkalk of Lunéville, Wilhelms- hall. " cylindra, variegated sandstone of Deux Ponts, Lunéville. Acrodus Gallieni, muschelkalk of Lunéville, Bareuth, Wilhelms- hall. " lateralis, muschelkalk of Lunéville. " Brazzii, variegated sandstone of Deux Ponts.

Acrodus minimus, bonebed of Aust Cliff, Lyme Regis. " acutus, sandstone of Tubingen. Ceratosodus heteromorphus, muschelkalk of Wilhelms-hall, Lunéville. " latissimus, bonebed of Aust Cliff. " curvus, bonebed of Aust Cliff. " planus, bonebed of Aust Cliff. " parvus, bonebed of Aust Cliff. " emarginatus, bonebed of Aust Cliff. " gibbus, bonebed of Aust Cliff. " Dadaleus, bonebed of Aust Cliff. " altus, bonebed of Aust Cliff. " dissuris, bonebed of Aust Cliff.

V.—Jurassic Formations.

a. Lias.

Leptacanthus templepinus, Lyme Regis. Myriacanthus paradoxus, Lyme Regis. " retroversus, Lyme Regis. " granulatus, Lyme Regis. Asteracanthus Stutchburgi, Charmouth. Hybodus curtus, Lyme Regis, Keynham, Wurttemburg. " crassispinus, Lyme Regis. " reticulatus, Lyme Regis. " formosus, Lyme Regis. " ensatus, Lyme Regis. " levisculus, Bristol. Acrodus nodalis, Lyme Regis. " latus, Lyme Regis. " gibberulus, Lyme Regis. " undulatus, Lyme Regis. " Analogus, Lyme Regis. Hybodus reticulatus, Lyme Regis. " pyramidalis, Lyme Regis. " medius, Lyme Regis. Sphenonchus hamatus, Lyme Regis. Thyellina prissa, Lyme Regis. Anthropterus Rileyi, Bristol. Squaloraja polyspondylus, Lyme Regis. Cyclarthrus macropterus, Lyme Regis. Ichthyodon Johnsoni, Charmouth.

b. Inferior and Middle Jurassic.

Nemacanthus brevipinnus, colite of Stonesfield. Leptacanthus longispinus, calc. of Caen. " semistratus, Stonesfield. " serratus, Stonesfield. Asteracanthus acutus, Bedford. " minor, England. " semisulcatus, Stonesfield, Purbeck (I) Pristacanthus securis, Caen, Stonesfield. Hybodus crassus, Towcester, Wasseraugen. " apicalis, Stonesfield, Hastings. " dorsalis, Stonesfield, Hastings. " marginalis, Stonesfield, Tilgate. " leptodus, Oxford clay, Oxford. " pleictus, France. Ceratosodus Phillippii, colite of Stonesfield. Strophodus longispinus, calc. of Caen. " serratus, Stonesfield, Dundry, Banville. " tenuis, Stonesfield, Dundry. " irregularis, inf. colite of Neneburg. " radiato-punctatus, Kelloway. " favosus, Stonesfield. Acrodus lelopteurius, colite of Bath. Hybodus grossiconus, Stonesfield, Caen. " polyprion, Stonesfield. " obtusus, colite of Caen. " inflatus, colite of Caen. " raristatus, colite (I). Ichthyodon Tesseiri, Mont Vohayes, Pfällingen, Oxford. " crypturus, Stonesfield. Ganosodus Coelli, Stonesfield. " Owenii, Stonesfield. " regulosus, Stonesfield. " neglectus, Stonesfield. Peltacodon falcatus, Stonesfield. " paittacinus, Stonesfield.

c. Upper Jurassic.

Asteracanthus ornatus, Shotover, Soleura. Hybodus striatus, Hastings. FOSSIL ICHTHYOLOGY.

Placoida. Hybodus acutus, Shotover. " strictus, Portland. " subcarinatus, Tilgate. Strophodus reticulatus, Oxford clay of Shotover. " subreticulatus, Portland stone of Soleure. Acrodus hirude, Tilgate. Hybodus dubius, Purbeck, Linkfield. undulatus, Purbeck, Linkfield. Sphenodon elongatus, Tilgate. Martini, Purbeck, Linkfield. Wagneri, Solenhofen. Astrodermus platypterus, Solenhofen. Euryarthra Munsteri, Solenhofen. Notidamus Munsteri, Streitberg. Oxyrhina paradoxa, Tilgate, Hildesheim, Rabenstein. Lamma longidens, Rabenstein, Streitberg. Ichthyodon Egertonii, Kimmeridge clay of Shotover. Bucklandi, Portland stone of Soleure. Townsendi, Portland stone of Great Milton, Oxford. Dupertai, Kimmeridge clay of Boulogne. Dupuyeri, Kimmeridge clay of Boulogne. Beaumontii, Kimmeridge clay of Boulogne.

VI.—Chalk Formation.

Ptychodus acutus, Lewes. spectabilis, Lewes. gibberulus, Lewes. arcuatus, Lewes. articulatus, Lewes. mammillatus, England, Belgium, Bellano, Paris, Delaware. decurrens, Lewes, Rouen, Bockum, Bellano, Ratisbon. altior, Sussex. polygyrus, Lewes, Quedlimburg. latissimus, Lewes, Bockum, Bennatack, Bellano. Mortonii, United States. Hybodus acutus, Lewes. Chimera Mantelli, Lewes. Spinax major, Lewes. Acrodus rugosus, Maestricht. transversus, Sussex. Strophodus asper, Lewes. punctatus, greensand of Kehlheim. sulcatus, greensand of Maidstone. Scylliodus antiquus, Kent. Thyella angusta, Bamberg near Manster. Notidamus microdon, Sussex. pectinatus, Sussex. Corax pristionotus, calc. of Maestricht. Kastelensis, calc. of Aix-la-Chapelle and Haldem. falcatus, Kent, calc. Pl. Stretha, Quedlimburg. appendiculatus, calc. of Maestricht, Salagitter. affinis, calc. of Maestricht. Galeocerdo gibberulus, marl of Haldem. denticulatus, calc. of Maestricht. Sphyrna denticulata, Pl. Stretha. Hemipristis serra (?) chalk of Ratisbon, Haldem. Carcharias tenuis, greensand of Sentis. acutus, marl of Bockum. Odontus appendiculatus, chalk of Sussex, Normandy, Delaware. latius, Maestricht. crassus, greensand of Ratisbon, Kehlheim. sandwichianus, Quedlimburg, Pl. Stretha. verratus, Maestricht. Oxyrhina Mantelli, chalk of Kent and Sussex. subinfusa, greensand of Bohemia, Perte-du-Rhone. Zippel, greensand of Ratisbon. Lamma acuminate, chalk of Kent, Sussex, Yorkshire, Aix-la-Chapelle, Stretha. graeilis, calc. of Neufchâtel. subulata, marl of Bognor, Quedlimburg, Ratisbon. Rhapidodon, Lewes, Ratisbon. Broomii, calc. of Maestricht. plans, chalk of Sentis. Ichthyodon iguanoides, greensand of Maidstone. brachyurus, gars, England. Palaeodon Mantelli, chalk of Kent. Sedgwicki, Cambridge.

VII.—Tertiary Formation.

Ptychopleurus Faujasi, Paris. Myliobates Brongniarti, Ghent.

Myliobates tollipicus, London clay of Sheppy. Sternumbili, Breuil. Owenii, London clay of Sheppy. acutus, London clay of Sheppy. canaliculatus, London clay of Sheppy. lateralis, London clay of Sheppy. marginalis, London clay of Sheppy. Zygobates Studeri, molasse of Switzerland. Woodwardii, crag of Norfolk. Galena Cuvieri, Monte Bolca. Notidamus serratusimus, London clay of Sheppy. primigenus, molasse of Switzerland. Corax Egertonii, Maryland. Galeocerdo aduncus, molasse of Switzerland. Hemipristis serra, molasse of Switzerland and Saubia. Glyptis bastaalis, London clay. Carcharodon megalodon, molasse of Dax, crag in Maryland. rectidens, Novant. productus, Malta, Alzy, Apt. polygyrus, molasse of Switzerland, Maryland. suicidens, Castell-Arquato, Solissone. auriculatus, Dax. angustidens, Krossenberg. turgidus, Florheim. lanceolatus, Krossenberg. turbatus, Sheppy. megalothis, Maryland. discuris, Ghent. suberratus, London clay. Escheri, molasse, Krossenberg. Otodus obliquus, London clay of Sheppy, Saster. lanceolatus, Krossenberg. macrotus, Sheppy, calc. gromier of Véteuil. tricuspis, Wilhemshöhe. subplicatus, Bünde. trigonatus, Krossenberg. apiculatus, Véteuil. Oxyrhina mantelli, molasse. xiphodon, Dax, Dax. trigonodon, Valley of the Rhine. plicatilis, Castell-Arquato. quadran, molasse, Valley of Rhine. leptodon, Worontop, Pleicheim. Desori, molasse of Wurttemburg, Osnabrück, Bünde. crassus, Valley of the Rhine. minuta, Osnabrück. Lamma elegans, Sheppy, Paris, Grignon, Dax, Bordeaux, Italy. cupidatus, molasse of Valley of Rhine. compressus, London clay, calc. of Chaumont. depressa, molasse of Switzerland, Valley of Rhine. crassidens, palaeform iron ore of Maestricht. Hopel, Sheppy. verticalis, Sheppy. contortidens, crag, Thlengen-molasse, Valley of Rhine. dubia, molasse of Switzerland. Ichthyodon Helveticus, molasse of Switzerland, Olten. Elasmodus Hunteri, Sheppy. Palaeodus compressus, London clay. Edaphodon Bucklandi, Bagshot sand. leptognathus, Bagshot sand. corynathus, London clay, Sussex. Passalodon rastrellatus. Trygon Garmani, Monte Bolca. oblongus, Monte Bolca. Myliobates tollipicus, London clay. gonophorus, London clay. Dixonii, London clay. stratus, London clay. punctatus, London clay. gyratus, London clay. jugalis, London clay. nitidus, London clay. Colci, London clay. heteropterus, London clay. Regalis, Brixham. angustus, Eckelheim. Aetobates irregularis, London clay of Sheppy, Sussex. subarcatus, London clay of Sheppy, Berlin. arenatus, Swiss molasse. Zygobates Studeri, Swiss molasse. Woodwardii, crag of England. Raja antiqua, crag. ornata, Piacenza. FOSSIL ICHTHYOLOGY.

VIII.—UNCERTAIN FORMATIONS.

Ctenoids.

Ceratodus Kaupii. Notidensus recurvus, tertiary (?) Corax planus, chalk (?) Galeocerdo latidens, tertiary (?) Sphyra priscus, chalk (?) „ dubia, molasse (?) „ lata (?) Hempristis pavida, molasse (?) Carcharodon megalodon, Maastricht (?) „ semiserratus, Malta (?) „ heterodon, Normandy (?) „ leptodon, tertiary (?) Otodus recticonus, Malta (?) Oxyrhina retroflexa, tertiary (?) Lamna acutissima, tertiary (?) „ duplex, tertiary (?) Gamodus curvidens (?) Elasmodus Greenoughi (?) Myloblepharus micropleurus (?) „ Stockelli (?) „ subrufus (?) Actobates salutatus (?)

ORDER III.—CTENOIDS, ARRANGED ACCORDING TO GEOLOGICAL POSITION.

I.—CHALK FORMATION.

Sphenocephalus fasicaudus, quadrasterstein of Westphalia. Acrocastor parvus. Hoplopteryx antiqua. Beryx Zippel, flag-stone of Bohemia. „ ornatus, chalk, Sussex. „ radiana, chalk, Sussex. „ micropleurus, chalk, Sussex. „ Germanicus, quadrasterstein of Westphalia. Rhacolepis latus, chalk of Brazil. „ buccalis, chalk of Brazil. „ Offertii, chalk of Brazil.

II.—SCHISTS OF GLARES.

Acanth ovis. „ Regleyi. „ arcuatus. „ oblongus. „ minor. Podocys minutus. Pistularia Koenigii.

III.—MONTE BOLCA AND LEBANON.

Pristigenys macrophthalmus, Monte Bolca. Myripristis homopterygias, Monte Bolca. Holocentrum pygmaeum, Monte Bolca. „ pigmentum, Monte Bolca. Cyclopoma gigas, Monte Bolca. „ spinosum, Monte Bolca. Lates gracilis, Monte Bolca. „ gibbus, Monte Bolca. „ noterus, Monte Bolca. Apogon spinosus, Monte Bolca. Labrax lepidotus, Monte Bolca. „ schizurus, Monte Bolca. Smerdis miramcathus, Monte Bolca. „ pygmaeus, Monte Bolca. Enchelodus pygmaeus, Monte Bolca. Dules temminckii, Monte Bolca. „ medium, Monte Bolca. Pelates quinquepunctatus, Monte Bolca. Serranum microstomum, Monte Bolca. „ occipitalis, Monte Bolca. „ ventralis, Monte Bolca. Sparnodus macrophthalmus, Monte Bolca. „ ovalis, Monte Bolca. „ alivellis, Monte Bolca. „ micromaculatus, Monte Bolca. „ elongatus, Monte Bolca. Pagellas microdon, Monte Bolca. „ leptosternus, Lebanon. Dentex leptacanthus, Monte Bolca. „ crassispinus, Monte Bolca. „ breviceps, Monte Bolca. „ microdon, Monte Bolca. „ ventralis, Monte Bolca.

Pristopoma fureatum, Monte Bolca. Odontestes sparoides, Monte Bolca. Pterygocephalus paradoxus, Monte Bolca. Callipteryx spectabilis, Monte Bolca. „ reticulata, Monte Bolca. Gobius maceratus, Monte Bolca. „ microcephalus, Monte Bolca. Acanthurus tenellus, Monte Bolca. „ ovalis, Monte Bolca. Nasus nuchalis, Monte Bolca. „ rectifrons, Monte Bolca. Semionophorus velifer, Monte Bolca. „ vellicans, Monte Bolca. Ephippus longipennis, Monte Bolca. „ oblongus, Monte Bolca. Scaphichthys frontalis, Monte Bolca. Zanclus brevirostris, Monte Bolca. Pomacentrus maculatus, Monte Bolca. Platax altissimus, Monte Bolca. „ macropterygius, Monte Bolca. „ papilio, Monte Bolca. Pygeus gigas, Monte Bolca. „ nobilis, Monte Bolca. „ oblongus, Monte Bolca. „ dorsalis, Monte Bolca. „ nuchalis, Monte Bolca. „ Coleanus, Monte Bolca. „ Erythron, Monte Bolca. „ gibbus, Monte Bolca. Toxotes adspersus, Monte Bolca. Pistularia temminckii, Monte Bolca. Aslantoma Bolcense, Monte Bolca. Urophyes fistularis, Monte Bolca. Amphiplus longirostris, Monte Bolca. Rhamphosus aculeatus, Monte Bolca. Rhombus minimus, Monte Bolca.

IV.—TERTIARY FORMATION.

Lates macrurus, calc., greensand of Sèvres. Labrax aspius, calc., greensand of Passy. Smerdis ventralis, gyp. of Montmartre. „ macrurus, lignite of Apt. „ minutus, gyp. of Aix in Provence. Perca lepidota, fresh-water calc. of Oeningen. „ angusta, lignite of Ménat. „ Beaumontii, gyp. of Aix in Provence. Dentex Panjasi, calc., greensand, Nanterre. Sargus Cuvieri, gyp. of Montmartre. Cottus brevis, fresh-water calc. of Denizgau. „ aries, gyp. of Aix in Provence. „ papyraceus, lignite of Monte-Viale, in Vicentine. Macruronus altus, calc., greensand of Nanterre. Holocanthus microcephalus, calc., greensand of Châtillon. Platax Woodwardi, clay of Suffolk. Sciaenuss Bowerbankii, London clay of Sheepy. „ crassior, London clay of Sheepy. Magil princeps, gyp. of Aix in Provence.

V.—FORMATION UNKNOWN.

Smerdis latior (?)

ORDER IV.—CYCLOIDS ARRANGED ACCORDING TO GEOLOGICAL POSITION.

I.—CHALK FORMATION.

Enchodus halocyn, chalk of Lewes. „ Panjasi, chalk of Maestricht. Istius grandis, greensand of Westphalia. „ macrocephalus, greensand of Westphalia. „ microcephalus, greensand of Westphalia. „ gracilis, greensand of Westphalia. Osmerus Cordiei, greensand of Ibbenbusen. Osmeroides Monasterii, greensand of Ringenrode, near Munster. „ Lewesiensis, chalk of Lewes. „ granulatus, chalk of Lewes. Acrognathus hoopii, chalk of Lewes. Anableps typus, chalk of Lewes. Tetrapterus minor, chalk of Lewes. Hypsodon Lewesiensis, chalk of Lewes. Saurocephalus lanciformis, chalk of New Jersey. „ striatus, chalk of England. Saurodon Leanius, chalk of Lewes. FOSSIL ICHTHYOLOGY.

Cycloids.

Cladoeyclus Lewesienis, chalk of Lewes. Gardineri, chalk of Brazil. Calamopleurus cylindricus, chalk of Brazil. Halec Sternbergii, Haptonite of Bohemia.

II.—Schists of Glaris.

Palaeorhynchus longirostris. Glariensis. Iatum. Medium. Coel. Microspondylum.

Pallimphyses longus. Brevis. Iatum. Archaeus Glariensis. Brevis.

Jurassica macrurus. Pleiosomus microspondylus. Elopides Coelius. Anenchelum Glariensium. Isopleurum. Dorsalis. Heteropleurum. Iatum. Longipenne.

Neopteryx crassus. Elongatus. Osmerus Glariensis. Clupea brevis. Megaptera. Sclerorhynchus. Uropteryx elongata. Microspondylus Escheri.

III.—Monte Bolca and Lebanon.

Gasterosteus rhombus, Monte Bolca. Oblongus, Monte Bolca. Acanthoneus Glariensis, Monte Bolca. Vomer longirostris, Monte Bolca. Lichtia prica, Monte Bolca. Trachinotus melampus, Monte Bolca. Vomer parvulus, Lebanon. Carangopsis latior, Monte Bolca. Dorsalis, Monte Bolca. Analisis, Monte Bolca. Maximus, Monte Bolca. Amphilistium paradoxum, Monte Bolca. Doctor leptosoma, Monte Bolca. Thymus protergyrus, Monte Bolca. Osteocephalus oblongus, Monte Bolca. Orcynus leucostictus, Monte Bolca. Iatum, Monte Bolca. Cybium speciosum, Monte Bolca. Xiphopterus falcatus, Monte Bolca. Holostenus esculinus, Monte Bolca. Engraulis evolans, Monte Bolca. Sphyraena boleensis, Monte Bolca. Gracilis, Monte Bolca. Amici, Monte Bolca. Maxima, Monte Bolca. Rhamphognathus paralepidotes, Monte Bolca. Mesogaster sphyraenoides, Monte Bolca. Spilacanthus bennettii, Monte Bolca. Labrus Valentinus, Monte Bolca. Lophius branchiatus, Monte Bolca. Atherina macrocephala, Monte Bolca. Minutissima, Monte Bolca. Clupea macrospoma, Monte Bolca. Dentex, Marazzo Struttiamo. Beurrardi, Lebanon, Acre. Brevisima, schist of Lebanon. Iatum, schist of Lebanon. Temminckii, Radus and Mondrino near Rimini. Minima, schist of Lebanon. Leptotes, Monte Bolca. Cyprinodon, Monte Bolca. Minuta, Monte Bolca. Platynus elongatus, Monte Bolca. Gigas, Monte Bolca. Cetogaster annis, Monte Bolca.

Clupeina macrocephala, Monte Bolca. Anguilla latispina, Monte Bolca. Ventralis, Monte Bolca. Brevicula, Monte Bolca. Branchiostegalii, Monte Bolca. Interspinalis, Monte Bolca. Leptoptera, Monte Bolca. Zechtyspis tigrinus, Monte Bolca. Sphagobranchus formosanus, Monte Bolca. Ophiurus acutidens, Monte Bolca. Leptocephalus tanias, Monte Bolca. Gracilis, Monte Bolca. Medius, Monte Bolca.

IV.—Tertiary Formation.

Acantohydrus angustus, fresh-water limestone of Oeningen. Cobitis contortula, fresh-water limestone of Oeningen. Cephalotes, fresh-water limestone of Oeningen. Gobio pallasi, fresh-water limestone of Oeningen. Tinca farcata, fresh-water limestone of Oeningen. Leptosoma, fresh-water limestone of Oeningen. Microgopterus, fresh-water limestone of Steinheim. Leuciscus Oeningensis, fresh-water limestone of Oeningen. Iatiusculus, fresh-water limestone of Oeningen. Pusillus, fresh-water limestone of Oeningen. Heterurus, fresh-water limestone of Oeningen. Leptus, tripoli of Siebengebirge. Macrurus, lignite of Boon and Stöchen. Papyraceus, lignite of Bilin. Cephalos, lignite. Hartmanni, calc. tert. of Steinheim. Gracilis, calc. of Steinheim. Brevis.

Aspius gracilis, fresh-water calc. of Oeningen. Brongniarti, lignite of Ménat. Rhodus elongatus, fresh-water calc. of Oeningen. Iatior, fresh-water calc. of Oeningen. Cyclus Valenciennesi, lignite of Ménat. Minor, fresh-water calc. of Oeningen. Lebias cephalotes, terriaries of Aix, Provence. Gobio, lignite of Senne, Fichtelgebirge. Meyeri, near Frankfort. Cyclus cyclus, marl of Pezaro, marl of Gesso, St. Angelo. Perpustula, fresh-water calc. of Oeningen. Exos Otto, diluvial marl of Silz. Lepidotus, fresh-water calc. of Oeningen. Sphenolepis squamosus, Aix in Provence. Cuvieri, plaster quarries of Montmartre. Mallotus villosus, coast of Iceland. Allos elongata, tripoli of Oran. Colocephalus salmoensis, London clay of Sheppy. Megalops priscus, London clay of Sheppy. Notacus laticaudus, gyps. of Montmartre. Halecoptis laevis, London clay of Sheppy. Clupea Goldfussi, environs of Bingen. Anguilla variabilis, calc. of Aix. Maxillaris, fresh-water calc. of Oeningen. Labrus Ibetensis, Sicus medusa. Acanthoneus Bertrandi, Schio in Vincentine. Zeus priscus. Hemirhynchus Des Hayes, calc. grosse of Paris. Cybium macrospoma, London clay of Sheppy. Goniognathus coryphomoides, London clay of Sheppy. Maxillaris, London clay of Sheppy. Tetropterus priscus, London clay of Sheppy. Colorhynchus rectus, London clay of Sheppy. Sinatus, London clay of Sheppy. Sphyraenodus priscus, London clay of Sheppy. Cyprinodon priscus, London clay of Sheppy. Hyposodon tollapicus, London clay of Sheppy. Oblongus, London clay of Sheppy. Cetogona Coel, London clay of Sheppy. Jave, London clay of Sheppy. Brachygymnus tenueceps, London clay of Sheppy. Rhychocephalus branchialis, London clay of Sheppy. Pachycephalus cristatus, London clay of Sheppy. Podoccephalus nitidus, London clay of Sheppy. Bothrostetus latus, London clay of Sheppy. Brevisrons, London clay of Sheppy. Rhinocephalus planiceps, London clay of Sheppy. Ampheristus tollapicus, London clay of Sheppy. Ptychocephalus radiatus, London clay of Sheppy.

(T.S.T.)