(helleborus), a genus of plants of the nat. ord. Ranunculaceae, all of which possess very active purgative qualities. (See Botany.) The black hellebore was a famous remedy among the ancient Greeks and Romans, especially in mania: and so prevalent was the belief in its efficacy in imparting clearness to the mental faculties, that the most celebrated philosophers used to prepare themselves for intellectual labour by drinking an infusion of the leaves of this plant. The best grew in the island of Anticyra in the Ægean Sea, and the gathering of it was accompanied with superstitious observances.

HELMINTHOLOGY:

(ANNELIDA.)

The title of this article was formerly bestowed on a much larger group of animated beings than that to which it has been here restricted. The Linnean group of Vermes contained, in fact, the whole of the intestinal and other worms, the molluscous and testaceous tribes, the Zoophytes and Infusoria—which now form the natural materials of many classes. We here apply it exclusively to the Annelida, or red-blooded vermes, of which the medicinal leech and earth-worm afford familiar examples. Bruguière and others have no doubt conjoined them, in comparatively recent times, with the intestinal tribes; and it was at one time our intention (see Animal Kingdom, § Divisions) to have adopted that arrangement. But we conceive it to be more in accordance with the principles adopted in our other systematic articles, to abide by the example of Cuvier, and, referring the latter to the radiated or zoophyatical division, to include in the article Helminthology the Annelida alone. In truth, the intestinal tribes exhibit no organs of respiration, either tracheal or branchial—no traces of a true circulation—and their nervous system is extremely obscure. It will therefore become apparent, from the following definition, how greatly the Annelida differ from the creatures just named.

The Annelida or red-blooded worms form the first class of the articulated or annulose division of the animal kingdom. Their blood, of a red colour, resembling that of the vertebrated animals, circulates in a double system of closed vessels, that is, in arteries and veins. This system, though destitute of a heart properly so called, is sometimes provided with one or more distinct fleshy ventricles. Respiration is carried on through the medium of organs, which are sometimes external, occasionally developed beneath the surface of the skin, or sunk more deeply into the interior. They may all be presumed to breathe by means of branchiae, although the respiratory system of the so-called Abbranchial Order is still in some respects obscure. The branchiae or respiratory organs of the greater number are external, and vary considerably in their size, form, number, and position. Their body, of a softish texture, is more or less elongated, and always divided into numerous rings or segments, of which the anterior, known under the name of head, scarcely differs from the others, except by the possession of a mouth, and of the principal organs of the senses. None of the Annelida possess articulated members properly so called, but in room of these many are furnished with setiferous mammillae, or fleshy projections, bearing bundles of hairs or bristles, and forming what may be called pedes spurii, of which the number is extremely various. These peculiar organs are sometimes composed of two parts, the one superior and dorsal, the other inferior and ventral. The muscular power resides in the interior, and is capable of producing only an undulatory or creeping movement—

1 From Ἀνελιδα, a worm, and ἀποστελλω, a discourse. 2 For a description of these primary divisions of the animal kingdom, see Animal Kingdom, § Third Primary Division. The locomotive parts being incompetent to sustain the body.

The organs of the mouth consist sometimes of parts resembling jaws, more or less developed, sometimes of a simple tube. The organs of the external senses are composed of fleshy tentacula, sometimes articulated, and of certain blackish points, not existing in all the species, regarded as eyes. The nervous system consists of a double ganglionic cord, analogous to that of insects, as already described in our art, Entomology. In regard to their natural habits, most of these creatures are aquatic (the Lumbrici or earthworms excepted), and a great majority marine. Some dwell in holes beneath the waters, others form tubes or tunnels of mud or other matters, or even transude from their own bodies a calcareous secretion, which forms around them a protecting covering. Considered sexually, they are for the most part hermaphrodite, and some require reciprocal communication.

It will be perceived, even from the preceding brief exposition, that the Annelida are animals of a very peculiar nature. Although their nervous system coincides with that of the other articulated classes, and although their bodies are likewise divided by transverse sections, yet their locomotive organs are entirely dissimilar to those of the Crustacea, Arachnides, and Insects. Their setiferous mammillae are merely retractile sheaths; and the hairs or bristles which they inclose are in no way comparable to the feet of the last-named classes, but are organs of a very different nature.

The Annelida are few in number compared with insects and other articulated classes, and the greater proportion are marine. Their possession of red blood is a singular character in animals so low in the scale, and one not possessed by the molluscous tribes, which are yet regarded as their superiors in other points of organization. Some peculiarities in the circulating fluids of these creatures have been recently described by Dr Williams. With the exception of one or two species, two distinct and separate fluid elements of nutrition exist in these creatures—one, consisting of the proper and true blood, is contained in closed vessels, and moving in a definite orbit, constitutes a well-marked circulation; the other is a liquid mass, filling the open space which, in all species, intervenes between the intestine and the integument, holding organic corpuscles in suspension, varying in different species, and performing irregular to-and-fro oscillations under the agency of the muscular contractions of the intestine and integuments. On these two fluids two separate physiological functions devolve, each essential to the maintenance of life in the Annelida. All the recesses and ramifications of the general cavity of the body in these animals communicate freely with each other, constituting thus one common space. This cavity is lined by a distinct membrane, which is obviously the anatomical analogue of the peritoneum, and is filled by a fluid which is unquestionably an organic fluid. Dr Williams adduces reasons for regarding it as physiologically allied to the chyle of the higher animals, and the containing cavity as the prototype of the peritoneal. This general splanchnic chamber he therefore names the peritoneal cavity, and its liquid the peritoneal fluid, or the chyle-aqueous fluid of the peritoneal cavity. As the peritoneal membrane of the Annelida is not vibratory, the oscillations of the fluid contents cannot be caused by ciliary vibration. This fact is regarded as distinguishing the class from the Echinodermata, of which, in all the species, the peritoneal space is richly lined with vibratile cilia. The real character of this fluid was till recently unknown. Its coagulating principle consists of fibrine, and there can be no doubt that the greater portion is composed of sea-water. In a few minutes after removal from the body of the animal, it throws down an unquestionable coagulum, like the clot of true blood. The organic corpuscles cohere into groups and masses, and sink with the clot. Mechanically and physiologically this fluid is immediately essential to the maintenance of life—mechanically, by preventing contact between the intestine and integument, thus favouring the circulation of the blood proper; and physiologically, by furnishing the pabulum out of which the latter fluid is perpetually renewed or reinforced. In the genus Sabella this peritoneal fluid is opalescent and thickly corpusculated; it does not change its colour with that of the true blood, since its colour is the same in those species which are distinguished by green blood, as in those of which the blood is red, although so generally charged with corpuscles. Aphrodita aculeata is an exception, and exhibits a fluid which, bearing no visible morphous substances, seems to depart but slightly from the standard of salt water. The physiological character of this fluid is unequivocally manifested in Glycera alba, in which it bears in great abundance blood-red flattened oval corpuscles, resembling those of the frog. This is the sole instance of an Annelid with coloured corpuscles in the peritoneal fluid. The blood proper in this species is so faintly red as to be nearly devoid of colour, and is quite incorporeal.

That the basis of this fluid consists of sea-water is rendered almost certain by the following expedient. If it is collected in adequate quantities (say from Arenicola or Teredinella nebula), and carefully filtered, and the clean liquor then submitted to evaporation, the crystalline products will be found identical with those resulting from the evaporation of simple sea-water. Dr Williams infers

---

1. "As to the external tube which the Chetopoda (by which term M. de Blainville designates the setigerous genera of the class Annelida) often inhabit, although it is frequently sufficiently regular and solid, it cannot however in any manner be compared to the shell of the Mollusca, not even where there is the greatest approximation, as in Dentalium and Siliporaria. These tubes of the Chetopods are always simple excretions from their body, which are by no means attached to it, and from which the animal may issue forth without dying immediately. We begin to observe something of this kind in the mucosity with which certain species line the whole hollowed in the mud or sand which they inhabit, as in the Arenicola, and some Lumbricidae. This is analogous to the mucous pellicle of the tube of the Amphitrites and the Sabellidae; but in the latter, surrounding this mucosity, is included externally a stratum, more or less thick, composed merely of mud or very fine grains of matter, or, in fine, of debris more or less thick, of shells and larger grains of sand, which the animal continually opens at different sites; there are also some of them more regular, which are completely calcareous. The double opening is a character whereby they are distinguished from tubular shells, the summits of which, on the contrary, is constantly imperforate. These tribes, however, appear constantly to grow, after the manner of tubular shells, by lamina or strata extremely thin, placed inside of and out-edgeing one another. From this result striæ marking the growth, more or less apparent outside; but we never remark longitudinal strike on their surface, nor anything indicating the delicate working of the edges of a mouth, as in the Mollusca. This character alone might suffice to distinguish them from the true tubular shells; but to this we may add, that the constant perforation of the summit of the tube of the Chetopoda never allows the animal, in growing and advancing in its tube, to form partitions there, whereas in the tubular shells the reverse is invariably the case. A final character which distinguishes the tubes of the Chetopoda is, that they are adherent, and fixed flatly, through a greater portion of their extent, on foreign bodies, which never takes place with the tubular shells." (Griffith's edition of Cuvier's Animal Kingdom, vol. xiii., p. 38.) We may add, that the young of the shell-bearing Mollusca are always born with shells, because that part forms, in fact, a portion of their skin; but there is no doubt that the young Annelida are produced in an exposed condition, and afterwards proceed, by a voluntary effort, to form their protecting habitations.

2. See his excellent and elaborate paper "On the British Annelida," published in the Reports of the British Association for 1851. London, 1852. Annelida, that this sea-water, under such circumstances, readily assumes the character of an organic fluid—that is, becomes vitalized with great facility by the solid organic elements contained in the peritoneal fluid. Whether the peritoneal fluid is organically capable of maintaining the nutrition of the solid structures of the system, cannot be directly proved; but it is scarcely susceptible of doubt, from the intricate manner in which the true blood-vessels afterwards coil in the midst of the fluid contents of the general cavity, that the former must absorb from the latter the elements from which the true blood is afterwards manufactured. It presents, in fact, according to our author, the same relation to the contents of the proper blood system of vessels as the chyle of the higher animals does to the true blood; the peritoneal fluid of the Annelida differing from the chyle of the mammalia only in the fact that the latter is contained in vessels, while the former rolls in a capacious chamber.

Although we are deeply indebted to M. Milne-Edwards for his ample exposition of the colour and distribution of the blood in the Annelida, he appears to have overlooked, if not mistaken, its corpuscular or microscopic character. "Mais, du reste," he remarks, "examiné au microscope, ce liquide ne m'a pas semblé différer du sang des autres animaux sans vertèbres. Les globules qu'on y voit nager n'ont pas du tout l'aspect de ceux propres au sang des animaux vertébrés; ce sont des corpuscules circulaires, dont la surface a une apparence framboisée, et dont les dimensions varient extrêmement chez un même animal." Mr Wharton Jones has also figured and described these blood corpuscles as supposed to exist in the earth-worm and leech. Now, Dr Williams, after the most careful and extended examination, states as follows:

"In no single species among the Annelida does the blood proper contain any morphic element whatever!" In all instances, without a single known exception, it is a perfectly amorphous fluid, presenting under the highest powers of the best microscope no visible corpuscles or molecules, or cells whatever; it is a limpid fluid variously coloured, as originally and correctly described by M. Milne-Edwards, in different species. No complete distinction into venous and arterial blood can be observed, and the plan of the circulation renders such a distinction only partially possible. In all cases the colouring matter is fluidified, and uniformly blended with the fluid mass of the blood; the colour therefore must be developed in the fluid mass, for there exist here no morphotic elements in the blood itself by which the separation of the coloured substances from the peritoneal fluid can be effected, unless indeed the parietes of the vessels of the blood-proper discharge this eclectic function. With one exception, namely, that of Glycera alba, in which they are red, the corpuscles of the peritoneal fluid are in all species destitute of colour. But it is not at all chemically impossible that the coloured ingredients may exist in this fluid in a colourless state, and that these ingredients, through entering into new combinations, may become brightly coloured after transition into the true blood. In consequence of the impracticable minuteness of the quantity, no direct chemical analysis of the blood in the Annelid can be executed. As to the colour, however, analogy removes all doubt that the red tinge is due to the salts of iron, and the green to those of copper. In those species in which the blood is light, yellow, opaque, or lymph-like, it does not follow that the salts of the coloured minerals are altogether absent; they may exist under colourless combinations. The physiologist cannot view with unconcern the question, which in this class of animals affects the mode in which the peritoneal fluid and the blood-proper stand related to each other. That the former is higher than the latter in degree of organization, no doubt can exist; but it is not quite clear that the true blood is reproduced out of the elements of the peritoneal fluid; since the vessels distributed over the parietes of the alimentary canal may take up some of the immediate products of digestion, before the latter exude into the general cavity of the body to mingle with its semi-aqueous contents. Nor can it be affirmed, from the evidence drawn from its composition, that the peritoneal fluid is unfitted to supply the means of nutrition to the solid structures, into the interior of which in every part of the body it intimately penetrates. It is more probable, because more in accordance with analogy, however, to suppose, that it is a manufactory in itself; that its corpuscles execute an office by which the mineral substances and proximate principles are vitally assimilated; that the corpuscular elements in the Annelida do in this fluid, what in the higher animals analogous bodies effect in the blood-proper. From these facts the physiologist may advisedly say thus much, that in these animals nature divides the vital fluids into two separate and distinct orders, on one of which the preparative and elaborative cell-agency devolves, on the other the work of solid nutrition. They prove with great clearness, that the corpuscular elements, either in the blood itself, or, as in this case, in some contributory fluid, are essential to the preparation of the blood-proper; for when in the zoological series, as in the higher articulata, this corpusculated fluid disappears, the blood itself becomes corpusculated; or when the peritoneal fluid, as in the Echinodermata, becomes less organic, then also morphotic elements are developed in the true blood. From these observations the inference may be further drawn, that between these two nutritious fluids there exists a definite physiological balance; that one is capable of absorbing or merging into the other, according as the observer ascends or descends the organic scale. The peritoneal system of fluid terminates at the standard of the insect, the true blood system traced downwards terminates at the Echinodermata."

The swelling of certain portions of the body in progression may be regarded as due to the interior fluids. These are driven to a given point of the containing cavity, where they are momentarily imprisoned by the contraction of the circular integumentary muscles before and behind,—thus producing a bulging. The muscles of the integument are then excited to action, and the fluid is forcibly compressed forwards or backwards, in accordance with the direction of the muscular agency. This is the mechanical use of the chyle-aqueous fluids of the peritoneal cavity, the physiological purposes of which have been already explained. Almost all the Annelida are struck, as it were, by paralysis, when this fluid is made to escape from its cavity by a puncture through the external walls. The power of motion is immediately suspended, and the body becomes flaccid and passive. The peritoneal fluid is really the fulcrum on which all muscular action is based, and without it these creatures cannot make the required contractions with sufficient effect and precision. But this is not the only mechanical use which it affords. It prevents that injurious pressure amid the internal organs which might impede or arrest the circulation of the blood. In the leech tribe it is the fluid contained within the stomach that accomplishes this important object. "Nothing in the history of the Annelida," says Dr Williams, "can be conceived more wonderful than the mechanically perfect and facile manner in which Linus longissimus, a worm of many yards in length, performs the feat of locomotion, and that too over craggy and rugged rocks." Without the conjoined action of these internal fluids, the motor apparatus would be incapable of effort.

The Annelida, as a class, may be said to undergo, in their earlier stages, few, if any, metamorphoses. The young Annelida seem at first to be entirely devoid of appendages, but the body does not in any instance exhibit those peculiar transmutations so observable in the growth of insects and crustacea.

In regard to the external parts, we shall here indicate a few of the most important,—premising, that the characters mentioned are not universal to the class, but rather confined to certain races. The head, in such as possess one, is a small anterior swelling, which bears the antennae commonly so called, and the eyes, and is distinct from the first segment of the body. The Nereids of Linnaeus are regarded by Latreille as the only Annelida of which the anterior segment merits the name of head, or possesses organs fit to be compared to eyes, more especially to those of the larvae of insects. The eyes, where such exist, are simple, extremely small, and appear like blackish points. The organization of the mouth varies greatly in the different orders. The parts called maxillae by Savigny are hard circumscribed parts, of a cornaceous or calcareous nature, to which Latreille does not accord the name of jaws. The latter author indeed seems to regard the Annelida as a suctorial rather than a masticating class. Most of them are carnivorous habits, and live on the blood of other creatures. The trunk or sucker is a contractile fleshy portion, constituting the mouth, and containing the so-called jaws. The latter portions, however, being adherent to the inner coats of the sucker, which is itself nothing more than a prolongation of the oesophagus, can scarcely be regarded as genuine jaws.

Several tribes have their branchiae uniformly spread over the extent of the body, or over its central portion, while others (and these usually dwell in tubes) bear those organs at their anterior extremity. In the erratic species, or such as are naked, and without fixed dwellings, they are usually disposed longitudinally along the sides of the body, there being one for each foot. Blood-vessels sometimes appear to spread into the setiform processes, and to convert them into respiratory organs.

We have already stated that Linnaeus placed the Annelida in his almost unlimited class of Vermes,—a vast and by no means well-combined group, which the later labours of Otho Frederic Müller, Pallas, and other naturalists, failed to cast into a much more natural mould. The great Swedish naturalist separated the true Annelida from each other, placing one portion of the group in the order Intestina, and the other in that of Mollusca. In Cuvier's earliest work (Tableaux Elementaires, &c., 1789), he restricted the class of worms to the Annelida and intestinal species, a mode of grouping previously practised by Bruguière in the Encyclopédie Méthodique. Subsequent investigations induced the French anatomist to raise the former to the rank of a separate class, which he named Vers à sans rouge, in a memoir read to the French Institute in 1802. On this same group Lamarck (Extrait du Cours, &c., 1812) bestowed the name of Annellides, which has since been very generally adopted. A slight disparity, however, still exists in the constitution of the class, in the works of Cuvier and Lamarck, the former including therein the genus Gordius, which the latter associates with the other Vermes.

But notwithstanding the valuable labours of these and other writers, the external structure of the Annelida cannot be said to have been at all rigorously determined, or viewed in relation to that of conterminous groups, till we received the fruits of Savigny's laborious and most delicate observations, originally presented to the Academy of Sciences. At that period Blainville was also occupied in the study of the same group, which, with the exception of the leeches, forms his class of Stipodes. He published an extract from his labours in the course of the ensuing year. Oken, Leach, Latreille, Dugés, Audouin, Milne-Edwards, and others, have likewise contributed to our knowledge of this curious and important class, in publications, to the majority of which we shall more particularly allude in the course of the present treatise.

In regard to the geographical distribution of the Annelida, our data are not yet sufficiently precise and numerous to admit of any satisfactory generalization. We have already said, that with the exception of the earth-worms (and even these require a moist abode), all the known species are aquatic. We may add, that the great majority inhabit the saline waters of the ocean. Most of the Naidi, however, occur in fresh water, and some true Nereids are found in the lakes of North America. Annelida of some kind or other are met with in all quarters of the globe, and the species of many genera are very widely distributed; but others, such as the Amphionome, for example, are characteristic of, if not peculiar to, the warmer seas. Undoubtedly the most magnificent are native to the Indian shores. It is in general on the coasts of the sea, in the midst of Thalassophytes, in the anfractuosity of madreporites, in the sand, and particularly in mud, that the Chetopoda are to be found; and if some species are more commonly to be met with in the open sea, as, for instance, the Amphionome, named by M. Savigny Pleione vagans, it appears that they may have been drawn along with marine plants by the currents, as is the case with many other animals. Their natural movements are extremely slow, and may be compared to those of slugs, although their appendages for locomotion are much more numerous. The Nereidæ, however, not only creep in a kind of serpentine manner over the surface of solid bodies at the water's edge, but frequently swim very respectably, either by successive undulations of the body, after the manner of cels and serpents, or by agitating their appendages, and thus making these organs serve as oars.

The utility, in an economical point of view, of the Annelida in general, to the human race, is by no means great. According to Pallas, the inhabitants of some parts of Belgium eat those portions of Aphrodita aculeata which compose the mouth; the Nereids and Arenicola, as well as the earth-worms, are extensively employed as baits for fish, and the medicinal uses of the leech are notorious; but, with these, and, it may be, a few other exceptions, little can be said regarding the direct benefits derivable from this peculiar class. Its subjects, however, are by no means on that account the less important in the eyes of the philosophical naturalist. Several of the Annelida possess a phosphoric property, from which Linnaeus named a certain species Nereis noctiluca. Others, characterized by the same attribute, were afterwards described by Sig. Viviani.

---

1 From annulus, a little ring. The body of these animals is composed of a series of annuli or rings, a formation which suggested to Lamarck the general name which they now bear. The substance of these rings is neither horny nor calcareous, but soft and fleshy, and thus so far differs from the truly articulated tribe in the entire absence of any approach to a hard skeleton, or the consistent covering of insects. The segments are divided from each other only by a circular band of muscular fibres, the annulations not being perfectly distinct from each other,—the longitudinal muscles passing over and under the constricting circular bands. Thus, as Dr Williams remarks, these segmentations of the Annelida are more apparent than actual. In addition to the works mentioned in the course of this article we would especially recommend Dr Williams' Report already referred to, and of which we have made frequent use. We may moreover refer the reader to M. de Quatrefages' elaborate Études sur les types inférieurs de l'organisation des mollusques, consisting of many Memoirs published in the Bulletin de la Société Philomathique de Paris, for the years 1848, 1850, and 1852. See also Siebold's Anatomy of the Invertebrata (translated by Dr Burnett), London, 1854; Dr Carpenter's General Physiology, 6th edit., Ibid., 1854; and Mr Rymer Jones's General Structure of the Animal Kingdom, 2nd ed., Ibid., 1856.

2 Système des Annelides, forming a portion of the great French work on Egypt.

3 Bulletin de la Soc. Phil., Mai et Juin 1818.

4 Griffith's Animal Kingdom, vol. xiii., p. 73.

5 Phosphoréa maris quattuordecim locoscentium animalorum novis specibus illustrata. Genus, 1805.

6 Phosphoréa maris quattuordecim locoscentium animalorum novis specibus illustrata. Genus, 1805. The presence or absence of the organs of motion, and the position of the branchiae, furnish natural characters of easy application, which modern zoologists have employed to signalize the primary groups. Lamarck divides the Annelida into three orders—les Apodes, les Antennes, and les Sédentaires; and in the system of Cuvier they likewise form an equal number of orders—les Tubicoles, les Dorsibranches, and les Abranchés. In both systems the Serpulæ occupy the highest position in the scale. Savigny's arrangement of these animals consists of five orders, of which the author has as yet treated only of four—viz., les Néréidées, les Serpulées, les Lombricinées, and les Hirudinées. He places the Aphrodites and Nereids at the head of the class. Latreille is also of opinion that these Annelida, especially the Nereids, so far as regards their external organization, are entitled to precedence, and make the nearest approach to the articulated animals provided with feet, such as Insects and Crustacea.

We shall here, in as far as general arrangement is concerned, follow the system of Cuvier.

ORDER I.—TUBICOLE, Cuv.

Some form a calcareous homogeneous tube, supposed to result from transudation, like the covering of testaceous Mollusca, but which does not adhere by any muscular attachment; others construct a covering by agglutinating grains of sand, broken shells, and other debris, by means of a membrane, likewise the result of transudation; while a third group are surrounded by a tube of an entirely membranous or corneous nature.

GENUS SERPULA, Lam. The body is composed of numerous segments; its anterior portion is enlarged in the form of a disk, armed on either side by several bundles of stiff bristles; and on each side of the mouth is a fan-shaped plume of branchiae, usually adorned by lively colours. At the base of each plume is a fleshy filament, one or other of which is always prolonged and dilated at the extremity into a disk of various form, which serves as an operculum, and closes the overture of the tube whenever the contained creature chooses to retire. Of this genus the calcareous tubes cover, by their tortuous windings, the surface of stones, shells, and other submarine bodies. The species are widely distributed throughout the seas of Europe, India, and America. The largest are indigenous to the warmer climates of the globe. Little is known of their instinctive habits or natural economy. They are said to feed on aquatic animalcules, which they seize by means of their branchial tentacula.

Linnaeus, and most of the naturalists of his time, placed the Serpula among the testaceous Mollusca. They now constitute a numerous genus, of which several species occur in the European seas. They are very contractile, and are supposed to feed on animalcules. A well-known species, S. tortuosa (fig. 1), has rounded tortuous tubes, of about three lines in diameter. Its operculum is tunnel-shaped, and its branchiae are often of a beautiful red, or varied with yellow and violet. Any object thrown into the sea is apt to be speedily covered by this species.

In tropical seas they usually form their encrusting habitations in the midst of corals, lengthening their tubes as the coral is built up around them. Their extent is sometimes equal to three feet; and the expanded gill-tufts are of extremely vivid colours, equalling in brilliancy the brightest carnations. Some of the many small species which occur along our own coasts are also remarkable for the beautiful tinting of their gills.

GENUS SPINORHIS, Lam. Branchiae much less numerous than in the preceding genus (from three to four on each side), placed anteriorly in a somewhat radiated form. A pediculated operculum, with a flat summit placed between the branchiae. Tube testaceous, and rolled after the manner of a Cornu ammon.

This genus is composed of very small species, which are found attached to fuci, shells, and other marine bodies. They frequently occur in great numbers, though always separate from each other. The animals are of a blood-red colour. We have figured the Sp. nautiloides of Lam. (fig. 2) synonymous with the Serpula spirorbis of Lin.

GENUS SABELLA, Cuv. Amphitrite, Lamarck. Body and fan-shaped branchiae resembling those of the preceding genus, but both the fleshy filaments adhering to branchiae terminate in a point, and do not form an operculum; they are sometimes even wanting. Their tube is rarely calcareous, and seems often formed of grains of very fine clay or mud. Most of the ascertained species are of considerable size, and are remarkable for the extreme delicacy and lustre of their plumpy branchiae.

One of the most splendid of the genus is figured by Dr. Shaw under the title of Tubularia magnifica. It is found on various parts of the coast of Jamaica, adhering to the rocks. It is extremely wary, and when approached instantly recedes within its tube, which on a further alarm also retires into the rock, so that specimens can be obtained only by breaking off portions of the mass. These, when put into tubs of sea-water, may be preserved for months, and the habits of the animals attentively studied. The species in question is characterized by a simple undulated tube of a whitish hue, the tentacula being varied by beautiful alternate bands of red and white. Sab. vesiculosa (fig. 3) is a British species described by Montagu. The internal texture of its tube is coriaceous, but the outer coat is invariably covered by coarse sand, intermixed with fragments of shells. Considerable variety exists in the form and aspect of the genus Sabella.

---

1 Régne Animal (ed. 1830), vol. iii. See also the two following works—Synoptische Übersicht der Ringelwürmer oder Anneliden; Nach Cuvier's Classification. (Mit vielen Abbildungen.) Lithogr. gr. imp. fol., Ebend. 1841. Schmidt's Neue Beiträge zur Naturgeschichte der Würmer, Jena, 1849.

2 Linna. Trans. v., p. 228, tab. 9.

3 Ibid. xi., p. 19, tab. 5.