(Peter), M.D., the son of an eminent attorney at Dorchester in the county of Dorset, by Mary daughter of Robert Haynes, was born March 17, 1711, and was educated at the Charterhouse (not on the foundation), whence he proceeded to Trinity College, Cambridge, and there took his degree of B.A. with distinguished reputation. During his residence at Cambridge, by his own inclination, in conformity with that of his parents, he applied himself to the study of divinity, with a design to enter into holy orders; but after some time, from what cause we know not, he altered his plan, and applied himself to the study of physic. In the year 1736, he went to Leyden, where he attended the lectures of Boerhaave, and the professors of the other branches of medicine in that celebrated university, for the space of two years or more. About the beginning of 1739, he returned to London, with a view to enter on the practice of his profession, supported by a handsome allowance from his father. Why he did not succeed in that line was easy to be accounted for by those who knew him. He was a man of a very liberal turn of mind, of general erudition, with a large acquaintance among the learned of different professions, but of an indolent, inactive disposition; he could not enter into junta with people that were not to his liking;

SUPPL. Vol. II. Part II.

(n) Vide Valsinger in Eduardum II. et Ipodiyma Neustria apud Dupuy.—Essai de Fred. Nicolai. in great quantities in certain lakes about thirty-five miles from Perané; and it is on account of these lakes only that the town is worthy of notice in this work; for though there are many columns in its neighbourhood, which indicate the site of ancient structures, none of them have inscriptions attesting their antiquity.

The eastern extremity of the most western lake Mr Browne found to be $30^\circ 31'$ North. No vegetation appears, except reeds, on the margin of the lake, which is very irregular in its form; so that it is not easy to say what may be the quantity of ground covered with water. It is higher in winter than in summer; and when it was visited by our author, its breadth did not exceed a mile, though its length was nearly four. Towards the end of the summer, it is said, these lakes are almost dry; and the space that the water has retired from is then occupied by a thick deposition of salt. Not far removed from the eastern extremity, a spring rises with some force, which much agitates the rest of the water. Close to that spring the depth was far greater than Mr Browne's height; in other parts it was observable that it did not generally exceed three feet. The thermometer near this spring stood at $76$, while in the open air it was $87$. The more western lake differs not materially from the eastern in size, form, or productions. The colour of the water in both is an imperfect red; and where the bottom is visible, it appears almost as if covered with blood. Salt, to the thickness of five or six inches, lies constantly in the more shallow parts. The surface of the earth, near the lake, partakes more or less generally of the character of natron, and, in the parts farther removed, offers to the foot the flight resistance of ploughed ground after a slight frost. The soil is coarse land. The water of the lake, on the slightest evaporation, immediately deposits salt. There is a mountain not far from the lakes, where natron is found in inflated bodies, near the surface, of a much lighter colour than that produced in the lake, and containing a greater portion of alkali. How thick the substance of natron commonly is in the lake, our author did not accurately determine; but those employed to collect it report, that it never exceeds a cubit, or common pike; but it appears to be regenerated as it is carried away. If ever it should be brought to supercede the use of barilla, the quantity obtainable seems likely to answer every possible demand.

**Terebratulæ (Anomia; Lin. see that article Encycl.)** have been supposed not to exist now but as petrified shells. This, however, is a mistake. The anomia is an inhabitant of every region, and has existed in every age. As many terebratulae were caught by Peroufe's people during his voyage of discovery, and as Lamason the naturalist thought they should be considered as a genus by themselves, he has given us the following description of the anomia, or, as he calls it, *terebbratula*, on the coast of Tartary:

The length of the shell varies from six to twenty lines, and its breadth from five to eighteen; there are, however, considerable varieties of proportion between different individuals, besides those arising from the different ages of the animal. It would be improper, therefore, to distinguish the various species of anomia by the proportion of their shells. The waving lines on the edges of the shell are equally defective, as distinctive characters; for our author observed in the same species the shell approaching or receding indifferently from the circular form, and, in some, the edges of the valves are on the same plane; whereas in others, one of the valves forms a salient angle in the middle of its curve, and the other a re-entering angle.

The shell is of moderate thickness, about that of a common mussel; it is somewhat transparent, convex like the cockle: neither of the shells is more sensibly arched than the other; that, however, which has the spur, is rather the most so, especially in the superior part.

On the surface of the shell are seen a number of slight transverse depressions, of a semicircular waved form, which reach the part where the shell ceases to be circular, in order to form the angle which supports the summit.

These striae are covered with a very thin and slightly-adhering periostium; in some specimens there are from one to three shallow broad depressions, radiating infensibly from the centre of the shell, and becoming more marked as they approach the edges, where they form, with the corresponding parts of the other shell, those salient and re-entering angles which have been mentioned. The periostium is rather more firmly fixed on the latter angles than on the former.

The shells are equal in the rounded part of their edge, and close very exactly; however, towards the summit, the spur of one of the shells reaches considerably beyond the other shell, consequently they are unequal, as in oysters.

The spur, or summit, is formed by the folding from within of the edge of the shell, and the elongation of its upper part. The folded edges form an oval aperture of a moderate size, through which the animal extends the muscule, by means of which it attaches itself to other substances. This shell is not, therefore, perforated, as its name of terebratula would seem to imply, the opening not being worked in one of the shells, but formed by the elongation of one shell, the folding in of its edges, and the approach of the other shell. The summit is not pointed, but round.

The ligament, as in the oyster, is placed between the summits, and does not appear on the outside; it adapts itself to the pedicle of the animal. As the summit takes up a considerable part of the shell, the valves are only capable of opening a very little without running the risk of being broken. It is very firm, though slender, and not easily to be discovered, being fixed in a small groove, which is filled up when the shell is shut by the corresponding part of the opposite shell. This ligament preserves its texture, even for a considerable time after the shell is emptied and become dry.

Oysters are without a hinge, the teeth which form it in many other shells not existing in them. The anomia has been considered as an oyster, because its hinge or teeth have not been examined; they are not visible indeed in the fossil specimens; but, in opening them when alive, the teeth composing the hinge are sufficiently visible, being even much larger than in the greater part of bivalve shells. The fossil terebratulae are almost always found with their shells closed; whereas the other bivalves have usually theirs either open or separated: the reason of this seems to arise from the nature of the hinge, that of the anomia not allowing it to separate, and the ligament, which is very tight, contributing to keep the two shells united. The teeth which form the hinge of the anomia approach very near to those of the *spondylus*, described by M. Adanson. In this last they are formed by two rounded projections, and in the anomia by the same a little elongated. It is above these teeth that the ligament is placed in the larger shell; there are between it and the teeth two cavities, one on each side, which serve to receive the teeth of the other valve. The teeth of the larger shell have, besides, a slight projection, which fits into a longitudinal furrow in the other shell in front of the teeth.

The substance which covers the inside of the shell holds, as in oysters, a middle place between *nacre* and the interior substance of shells, which are destitute of it. The degree of its lustre, polish, and thickness, varies with the age and circumstances of individuals.

The colour of the teeth is always white; that of the outer surface of the shell verges more or less to the ochre red, especially on the border. The inside has also a very slight tint of this colour, on a varying greyish-white ground.

There is visible on each side of the shell the impression of two very distinct tendons; a circumstance which forms a very essential difference between this genus and that of the oyster; this latter having only one tendon arising from the middle of the body. The impressions of the tendon in the largest shell are oblong, situated near the summit, and hollowed; each of them has curved transverse ridges, divided into two parts by a longitudinal furrow, representing the wings of certain insects. In the other valve the insertions have a different form; their situation is the same, but they are very irregularly rounded and encompassed by two fulcations, which are separated from each other by an intervening ridge, and then are continued in a right line towards the opening of the shell as far as about two thirds of its length. That part of the summit of the shell along which the pedicle of the animal passes, is longitudinally striated in the larger shell, of which the middle stria is the deepest; the longitudinal striae are divided into equal parts by a transverse depression. There are no similar marks on the other shell.

Our author dissected the animal itself, and found what he calls the *mantle* of the anomia, formed of a very fine membrane, lining the inside of both shells, and containing the body of the animal. Its origin is of the same breadth as the hinge of the shell, whence it divides into two lobes, lining both the shells; it forms, therefore, only a single aperture, terminating at each end of the hinge, and of the same breadth with the interior surface of the shell; it appears to have only one trachea, which is formed by the two lobes of the mantle.

Our naturalist having opened the shell, divided the ligament as delicately as possible, unixed the hinge, and detaching from the larger shell the lobe of the mantle, turned over the body of the animal. This operation exposed to view the large muscles which adhered to the shell; they are soft, membranous, and, as it were, fleshy on the inside, being covered with small fungiform glands. From the lower part of each muscle there proceeds a pretty strong tendon, which reaches to the extremity of the mantle; they run parallel to the edge of the shell, and at a considerable distance from each other; and are each enclosed in a sort of flatted sac, of the shape of a ribbon, which is filled with a red viscid matter. It appears that the place of insertion of the muscles, as well as the muscles themselves, which extend along the lobe of the mantle, furnish real blood, which is contained in three small fleshy red glandular bodies of unequal size, which are visible after having taken off the muscles; perhaps these constitute the heart of the animal.

The muscles which are inserted into the other shell are also divided into several parts; some are seen extending along the corresponding lobe of the mantle; many others rise up in a kind of tuft, which is fixed into the shell above; some again subdivide into such minute ramifications as not to allow of tracing their course, even with the assistance of a microscope; but others, more apparent, contribute to the formation of the pedicle which passes through the opening left between the two shells, is connected to each of them by several fibres, and fixes itself to some external body, principally to other bivalves. The muscles of the anomia have therefore three attachments, namely, to the inner surface of each shell, and to some external body.

The form of the pedicle is cylindrical, being enclosed in a muscular substance, which contains several fibres; it is from a line to a line and a half long, and two thirds in diameter. It adheres so forcibly to different substances, as that the animal, and all the muscles which contribute to the formation of the pedicle, may more easily be torn through than the pedicle detached from the place of its adhesion. The glutinous substance which connects them to each other, resists even the heat of boiling water. It is by means of this pedicle that the animal raises its shell so as to be, while in the water, in a position inclined to the horizon. The smallest valve is always the lowest, being that upon which the animal rests; the superior one being the larger, and serving as a covering. Our author thinks the animal has the power of locomotion.

After raising the lobe of the mantle he observed the ears. They are large, composed of two membranaceous laminae on each side, of which the superior is the narrower. These laminae are connected to each other by a thin membrane, so as to form only a single pouch. They have on their edges long fringes, which hang loose upon the mantle; but a very remarkable circumstance is, that their ears are supported by little bones like those of fish. The form of the ears is that of an arch; they are separated from each other on their lower part, where the fringes are the longest; so that the two ears on one side are perfectly distinct from those on the other side. The commencement of the ears is at the teeth of the hinge.

Between the ears are situate the stomach, oesophagus, and mouth; the whole forming a triangle, of which the mouth is the base. It is placed at the side of the hinge, and consists of a large transverse opening without lips or jaw-bone. The oesophagus is very short, but is capable of elongation when the animal opens its mouth. The stomach, which is of the shape of a pointed sac, is connected by a membrane to the bones of the ear. On opening the stomach, he found a small shrimp half digested.

At the bottom of the stomach is seen the intestine, of which it is, as it were, a continuation. It is extremely short, not exceeding half a line in a shell fifteen lines... Terebratula lines across, and is composed of a very slender membrane. The excrements are discharged upon the lobes of the mantle, but they are easily thrown out by the motions of the two lobes.

The little bones of the ears, already mentioned, had not formerly been observed in any of the terebratuline animals; whence the terebratuline approach nearer to fish than the inhabitants of any other shell. In the animals which are preserved in cabinets, there is found only a very small portion of these bones, whence they have obtained the improper appellations of tongue or fork, which indicate only the form of the fragments, and not their use.

The small bones of the ears are composed of several pieces, the principal of which is an oval form; it springs from the side of the hinge, of which it appears to be a continuation; thence it extends about two-thirds of the breadth of the shell, where it is reflected, and rests against the upper part of the fork, to the branches of which it is united by a simple superposition; a kind of articulation very common among the numerous small bones that compose the heads of fish. The fork extends from the summit a little more than one-third of the breadth of the shell; it is formed by a pivot which divides into two long and pointed branches; these are remarkably brittle, and support the extremities of the bones of the larger ears. The laminae, which compose a second set of ears, rests upon a curved bone, which on one side is attached to the inferior internal part of the bone of the larger ears, and on the other reaches to the side of the mouth of the animal, where it is united to another flat little bone, which is applied to a similar bone on the other side. These last little bones are exactly below the membrane which forms the mouth. All these bones are flat, very brittle, and surrounded with fibres and membranes. By their articulations the ears are enabled to move; they also support the body of the animal, which touches neither of the shells, but remains between them as upon trellises. The space between the branches of the bones of the ears is filled up with a transparent firm membrane; at the base of the fork is a similar one, and a perpendicular partition dividing the space occupied by the body of the animal from the rest of the shell. There are two orifices in this membrane communicating with the space between the two lobes of the mantle, and which serves as a trachea; for we have remarked, in the description of the mantle, that the two lobes are entirely separated from each other, and therefore do not form a real trachea.

From this description, it follows that the animals ought to be separated from the genus oyster, since it has a toothed hinge, several ligaments, and an interior organization wholly different; neither ought it to be confounded with the cockle, the shells of which are both equal, and are destitute of any fleshy periosteum, without reckoning other differences. It has still less analogy with the other bivalves, and therefore ought to constitute a peculiar genus; the species of which, both fossil and living, are very numerous.

See Plate XLIII., where fig. 1. is a front view of a terebratula of middle size. Fig. 2. is a view of the internal structure.—A A, laminae of the superior ears—B B, laminae of the inferior—C, the stomach—D, the anus—E E, the mantle—F, the oesophagus.