. a an) es Sse tea a ay. HAA AALS 1, yest i of tata i ‘i “ tts ib iy 4 Ry dathad ‘hi + eet eek a ‘ 4 = ZX SENN AAAS A RAS AS AAS AAAS AS AE AAS AS t Ws 4 nn x N S Me Wy Wi f Mollusks | Labrary VW Mb, EX LIBRI WZ ie tS SS KS nh ~~ a, = S2 A D S ‘ony ys Zz. ra Feo cof lus Of? 4a M ied oS ion of benders & i a iV Cc Be fom ~ * “f o ia > = . = ‘ / =A ~e is 2 ’ ‘ 3 ae =f SSS |e Moll THE GENERA RECENT AND FOSSIL | SHELLS, FOR ee USE a STUDENTS Geinehology and Geology : PLATES OF GEN ERA; ALSO CORRESPONDING LETTER-PRESS Descriptive of the Characters by which each Genus is distinguished. | i PARTICULARLY THE LAND, FRESH WATER & MARINE NATURE OF EACH GENUS, _. As well as the Strata in which the Fossil Species occur > ILLUSTRATED WITH hig 264 ORIGINAL PLATHS. BY JAMES SOWERBY, j=, F.L.S., M.G.8., &e. Vol. 1, Text. CONDUCTED BY GEORGE BRETTINGAM SOWERBY, F.L.S. - LONDON : G. B. SOWERBY, REGENT STREET, Price, Plain, 8 Guineas. HAGA Sh 1 a eae ah pea ‘ > -@HUTAM AXLIAM & MATA OED: AO Haye Waa AL Ay dob ata ys , iV Saal fa Ayaan, apse eines Lee PROSPECTUS. | B,; FORE entering upon our subject, we feel ourselves called upon to explain the nature of the Work we propose to bring under Public notice, and in some Measure to show its utility. In doing this we shall endeavour to be as brief as possible. As we have expressed ourselves in our Titlepage, our Work is to consist of Engravings illustrative of the GENERIC CuaractTers of the several classes generally included under the common name, SHELLS; and it will include, with but few exceptions, all that Zznné and Linneans receive under the term Vermes TESTACEA, dt is not our intention to adopt implicitly either the System or the Genera of any Author who has previ- ously written on Conchology, we certainly see great reasons for adopting many of the Genera lately estab- lished, and we are perfectly convinced that the im- mortal Linné would have done the same himself had the seen the very numerous subjects that have come under the notice of later writers, he would have found his own Genera inadequate, and have yielded to the force of necessity by establishing many- new ones. Neither do we intend to enter into the investigation of the subject farther than is necessary for the purposes of usefulness; but we do not mean to confine ourselves to one or two observations where we think the subject either requires or deserves a more full elucidation. Nor cah We observe any particular order ig the publication of PROSPECTUS. our Plates, but selecting the most characteristic speci- mens in illustration, we shall devote One Plate (very rarely more) to the elucidation of each Genus, and endeavouring as we proceed to ascertain the exact relation naturally existing between the various Genera, we shall give at the conclusion a Classification, arranged according to the more enlightened views we shall then have obtained. The Plates of this Work will be add not only original, but executed in his best manner, by a person of gener- ally acknowledged superiority of talent, by one who has already largely contributed by his labours to the advancement of Science in several branches of Natural History, a person whose entire labours for more than thirty years have been devoted to such useful and scientific objects: when we mention the name of JAMES SOWERBY, F.L.S. M.G.S5S. &e. _we are sure the scientific Public will credit us for our intention to furnish it with correctly executed Engravings. Indeed, our whole Work will be original, though we have no objection to adopting the phrases and language of those who have preceded us; some- times we shall gather information from them, and as far as we think they have done well we cannot do better than follow them, but never without examination; when- ever we. find them obscure or inadequate we will endeavour to explain and amend. Each of our Plates will be accompanied by a leaf, or more, of Letter- Press; in which we shall give a definition of each Genus and point out those characters in which it. differs from others nearest in resemblance to it, and thus establish the relation between the Genera. To render this Work as useful as possible, we shall men- tion the Land, Fresh Water, and Marine Nature of each Genus; point out the Strata in which the fossil species occur, as far as we are acquainted with them by our own observation; and add such general remarks as ay appear to us strikingly necessary in illustration PROSPECTUS. of our subject. To avoid every thing like a critical examination of the works of our predecessors we shall, in all cases, content ourselves with barely mentioning ny thing that occurs to us in the course of our pub- lication that is absolutely incorrect. So much for the nature of our Work: and while ‘we propose the attainment of a pleasing and scventific object, we shall experience little difficulty in showing its utility; indeed this is so obvious and so generally acknowledged, that we may assume it without wasting our time in endeavouring to prove it,—we shall content ourselves with showing how and to whom we intend to render it useful. . Ist, To the Collector of Shells, by making him acquainted with the distinguishing characters and rele tions of the subjects he collects ; without which know= ledge, Shells are a mere idle amusement that serves to gratify the eye without informing or improving the mind, and by the means of which they may be rem dered both a pleasant and profitable amusement. Qdly, To the Student in Conchology, also by pointing out the nature of the objects whose acquaib tance he wishes to cultivate, and enabling him to class them according to their several relations, and conse- quently to study them to advantage. 3dly, To the Student in Geology, because the characters of many formations, when considered with- out reference to the fossils they contain, are so variable that it is absolutely necessary for him to become acquainted with them, and with the Shells in par ticular, because they form so considerable a proportion of the Organic remains by which Strata may be iden- ‘tified and characterized. We beg leave, in conclusion, to assure the Scien- éific Public of our intention to neglect nothing that is im Our power to render our Work generally useful, and of our consequent willingness to profit by such oh ~ VANS RC Ne, ph ann nae ea i PROSPECTUS. information and observations as any kind Corres- pondents, who are also friends to Science, are willing ~ to afford us; we shall feel ourselves obliged by such, and shall consider it our duty to acknowledge them with becoming gratitude, whenever we make use of them. Feeling that the completion and consequent final ‘success of our Work depends, in a great measure, upon the encouragement it receives at its commence- ment, we beg leave to assure those who become pur- chasers, that it shall be continued, and with the utmost regularity, until it is complete, whether it answer our expectations or not, provided only that the actual expences we may incur be paid by it without giving us any profit. OPP I IS PEIN DD ETHERLA. ee a, Lamarck.—Annales du Mus. v. 10. t. 29—32. —igdioe- ; : byob TESTA irregularis, inequivalvis, adherens, wm- bonibus brevissimis, basi teste subimmersis. Cardo edentulus, undatus, subsinuosus, maequalis. Impressiones musculares due, distantes, laterales, oblonge. ligamentum externum, contortum, intus partim penetrans.—Lam. —— First distinguished by Lamarck in the Annales du Museum. On account of its irregular form and foliated structure it. might be mistaken for an Ostrea, but from that it may be distinguished by its having two oblong muscular impressions, in which character it approaches nearer to Chama, its hinge, however, is toothless, and has a strong, partly internal, ligament. Several species are described by Lamarck, all of which are found attached by the exterior of their lower valve to submarine rocks, and inasmuch as they conform to the irregularities of the place, cannot be strictly said to have any peculiar form, the muscular impressions, however, are lateral and rather distant. The beautiful pearly lustre of the substance of the shell in two species is much dwelt upon by Lamarck. | a _ ‘T'wo circumstances observable in the specimen of Eth. semilunata, drawn in our plate, would have induced us to suspect that this was a fresh water shell, or at least an inhabitant of #stuaries at the mouths of rivers; Ist, its having an epidermis, whicly remains only in those parts least exposed to the action of the water, the greater part, particularly of the upper valve, being eroded ina very irregular manner; and 2dly, its being partly covered with the remains of those ovate vesicular bodies, supposed to ETHERIA, be the eges of some molluscous animal, so frequently seew on fresh water shells; but Lamarck says that they are attached to the rocks at a considerable depth in the sea, on which account they are little known, having escaped the observation of collectors. Lamarck mentions singular bubble shaped, unequal swellings in the interior, but which appear to him to be accidental : these are very conspicuous in the lower valve of the specimen from which our drawing is taken, we think they are caused by the accidental introduction of little par- cels of sand ever which the animal, to obviate the inconve- niences their presence causes, has deposited a coat of shelly matter. He also speaks of an oblong callossity, which is as it were incrusted in the base of the “shell without forming any internal projection. Not known in a fossil state. The specimen from which our plate is drawn is in the possession of the Rev. Dr. Goodall, Provost of Eton College, &c. We have represented the inside of both valves, and the outside of the upper one. © PLACUNA. ~<+9o oe TESTA bivalvis, libera, suborbicularis, subequi- valvis, complanata. Cardo interior, cicatriculis duabus, basi convergentibus, superné divaricatis in valva inferiore ; costis duabus elongatis, longi- _tudine inequalibus, minis divaricatis in altera, ligamento precipué inservientibus. — Impressio muscularis unica, simplex, suborbicularis, | ee Easity distinguished from all other Genera by the two elongated, diverging coste, or lamine, of unequal length, to the external edges of which the internal ligament 1s at- tached, in the one valve; and by the two corresponding, but more divaricate, impressions in the other valve. All the species known tous at present,(which are not numerous), are extremely compressed, suborbicular, and nearly equivalve, the valve which has the two cardinal costa, commonly called the upper valve, being rather less concave than the other. The valves are very thin, more or less transparent, of a foliated structure, composed of perpendicular fibres as in Ostrea and Pinna. A single, nearly circular, muzscu- lar impression is observable in the centre of each valve, with sometimes a minute lunulate, more lateral one and less frequently a third, very small, also lateral one placed at nearly the same distance on the other side of the princi-. pal muscular impression. A part of the internal ligament, which unites the two valves at the hinge, spreads on both sides the wmbo in a transversely linear form, acutely dentated at its inner edge; this, on account of the imperfect state in which the specimens of this shell are generally brought to Europe, is very seldom observable. Slender, very obsolete tk diverge from the umboand cover the outside of both valves. — The recent species are inhabitants of the Indian seas: three are enumerated by Lamarck, of which the Anomia PLACUNA. Sella of V.inné, or Saddle oyster, and the Anomia Pla« centa, or Chinese Window Shell, are the best known and most easily distinguished. We have never seen any fossil species, but Lamarck describes one found near Metz, and figured in the Encycl. Method. t. 175, f. 1—4, from a specimen of this in our possession we judge it rather to be a Plicatula. Fig. 1. Outside of the lower valve of Pl. Placenta. 2. Inside of upper valve of the same. STRUTHIOLARIA. + Lamarck.—Encycl. Method. t. 431. f. 1. —~—+ Fe TESTA oblonga, turrita ; Aperturé oblonga, obli- qua, labio externo sinuoso, incrassato, revoluto, basi obliqué truncaio; labio interno incrassato, expanso, partem inferiorem anfractis ultimi et columellam tegente. oe Aw oblong turrited enivalve, with an obliquely placed ob- long aperture, outer lip thickened and turned outward, with twe sinuosities, one placed in an oblique direction, close to the base of the shell, and forming a sort of shallow canal, the other, rather above the centre of the lip, and less conspicuous; izver lip thickened, spreading over the lower part of the last volution and the Columella. By the above characters the shells of this Genus will easily be distinguished from those of Buccinum and Mure, the only two genera it could possibly be confounded with. The Murex stramineus of Gmel. may be considered as the Generic Type, which shell is however very distinct from Murex, and does not agree with Linné’s character of that Genus. 3 Lamarck established the Struthiolaria: apparently only one species was known to him, it is what we have called Struthiolaria straminea in our plate; had it not already been published under this specific name, we should gladly have adopted the more expressive one of nodulosa, by which Lamarck has designated it; a second, which we have called inermis, has lately been added: both are from the coast of New Zealand. S. inermis may be distinguished from S. stra- STRUTHIOLARIA. minea, or nodulosa, by its smaller size*, and its wanting the rather pointed tubercles that surround the upper part of the volutions of S. straminea: its less sinuous outer lip, the greater depth of the spiral line, and the less angular upper part of the outer lip, also distinguish it. The animal of this Genus is unknown: whether in its natural state the shell be covered with an epidermis or not, _or whether it have an operculum we are unable ta tell. Not known in a fossil state. Fig. 1 and 2. Str. straminea. 3 and 4. — inermis, * It may here be observed, that the comparative size cannot, in many cases, be considered as a good specific character; for we know that shells vary very much in size, even when full grown: here we think it may, for it is evident that the shells of this Genus do not complete the lip, nor form any varicose suture until the time of their adult state; consequently the smaller one cannot be taken for a young specimen, becanse it has already completed its sinuated revolute lip: and it has other distinguishing characters HIPPONYX. aT) ol De France.—Dict. des Sciences Nat. v. xxi. p. 185. on TESTA bivalvis, adherens, inequivalvis, equi- latera, impressionem muscularem in utraque valva, forma ferri equini, gerens; valva inferior atiixa, compressa, margine plerumque elevato; valva superior patelliformis, subconica, vertice sub- _marginali. Cardo edentulus. Liagamentum car- dinis nullum. We are not surprized that Linné, and even later writers, should have inciuded the shells of this genus in Patella, having been acquainted only with the upper valve. De France is the first person who was able to prove that it was composed of two parts, though he still considers it as an univalve, which has the extraordinary property of making a support, for the purpose of raising itself above the shells orstones to which it is attached, founding his opinion upon what he conceives to be a difference in the nature of the two valves; the upper one, in his opinion, resembling in its structure the Cyprewa, Voluta, and other similar shells, which he has observed sometimes disappear entirely in cer- tain situations, where they occur in a fossil state, leaving only the cast of their interior, and the impression of their external parts; andthe /ower valve, he thinks, resembles in its structure the Ostrea, a Genus, the shell of which, he believes, never disappears in a fossil state. We cannot co- incide with him in this opinion, for we see nothing in the ‘nature of Hipponyx different from other bivalves ; on the contrary, the numerous observations we have had in our power to make, appear to us only to strengthen the evidence in favour of the existence of a relation between this Genus and Orbicula, Crania, and Terebratula; and we suspect that the animal has, in common with those genera, two fringed arms or tentacula. In describing this Genus, we HIPPONYX. are, therefore, obliged to consider it as an equilateral in- equivalve, rather irregular bivalve; there is a muscular impression in each valve of the general form of a horse- shoe; the fibres of which this is composed are placed in a different direction from those composing the remainder of the shell, and appear to be more easily decomposed, for which reason there are frequently found fossil specimens with cavities in the place originally occupied by the mus- cular impression, particularly in the lower valve, which, in its general form, is orbicular, compressed, sometimes very much thickened, attached by its outer part to submarine bodies, its margin is for the most part elevated, more soin front than behind; its muscular impression can scarcely be called single, the two semilunar portions which compose it are placed close together; they are nearly confluent and narrow at the posterior part; more distant in front, where they are broader and rounder: it, however, has the gene; ral form of a horse-shoe. ‘The upper valve is patelliform, subconical, sometimes very much compressed; its vertex or umbo is inclined backwards, and towards the posterior margin; like the attached valve it has an internal muscular impression in the shape of a horse-shoe, placed near the - posterior margin, the two lobes of which are much more distant and obliquely truncated in front, but entirely con- fluent at the posterior part: there is a remarkable coinei- dence in the muscular impressions of this genus, with those of Terrebratula, which, in the lower valve, has two, placed near to each other, and in the upper valve a central one composed of two confluent portions. In Hipponyx there. is no cardinal ligament, nor are there any teeth. | It was from the circumstance of observing a cast of the interior of the upper patelliform valve attached to a lower valve that De France began to suspect the true nature of this shell; his suspicions were afterwards confirmed by his finding the two valves together on the outside of a specimen of Cerithium Cornucopia; and also by the discovery of an attached valve of Hippanyx mitratus. About the same time __ we were almost persuaded of the same fact by an examina- tion of the upper valve, and a comparison we instituted between it and some specimens of Orbicula and Crania which had just then failen into our hands; we had not, however, the means of proving the truth of our surmise; hut we have since met with several specimens of a small fossil species, the Hipponyx levis, in the inside of other HIPPONY xX. fossil shells from near Paris, which confirmed us in our opinion, and established the Genus. If any further eyi- dence of the bivalve nature of the Hipponyx were neces- sary, it is abundantly supplied by a recent discovery of our esteemed and liberal friend C. De Gerville’s, who had already enriched M. De France’s and our own collections, with many specimens of the detached valves. Inthe latter part of the Summer of 1821, he met with several fine specimens with both valves together, and attached to Ceri- thium Cornucopia, at Hauteville, in the Department de la Manche; some of these he has obligingly forwarded to us; and had not our plate been already in the printer’s hands, we should have availed ourselves of this opportunity, and have given a representation of one of them: if circum- stances should hereafter render it necessary we shall give a new plate. The only recent species that is certainly known to belong to the Genus Hipponyx, is the Patella mitrata of Linné, of which the attached valve is in M. De France’s collection. ‘The upper valves of several fossil species have. been described by Lamarck, among his fossil Patel/e#, under the specific names Cornucopia and dilatata; most of them are covered with strie diverging from the wmbo or vertex, and spreading to the edges all around; one is covered with strong coste, diverging in a similar manner, and another issmooth. All the fossil species known are from the Cal- caire grossicre of the French, which, we think, is nearly, if not quite, identical with our London clay; though we are not aware of asingle one having yet been found in England. We cannot conclude this article without recommending to those, who have opportunities of collecting shells ina living state, to pay an increased attention to their nature and eco- nomy. it appears to usa strong proof of the general careless- ness and inattention of collectors, that the true nature of so common a shell as Patella mitrata should so long have remained unknown, and that it should be, at length, dis- covered, not in the places where it is found abundantly, and where, consequently, the best opportunities were afforded, but by a person shut up in his study, at a distance from the sea-coast, and deprived of the means of observing it in its living state. There is reason to believe that several other recent species exist, but that only their upper valves HIPPONYX. are known, because those who have picked them from their native rocks, have not taken the pains to observe in what manner they were attached. Fig. 1. to6. The upper valve of Hip- | valves of Hipponyx levis. ponyx Cornucopia, in various stages } Fig. 11. 14. 15. Insides of the same of growth. valve of the same. Fig. 7. Outside of the lower valve. | Fig. 12. 16. Insides of lower valves Fig. 8.9. Inside of the lower valve, of Hipponyx levis, attached to pot- in different states. tions of other shells. Fig. 10. 13. Outsides of the upper | x ° TESTACELLUS. He ate a uaa Oe Ne cee “a i 3 iad oF ‘ai iwog 14° y iy onn! ork af nels eee pret ‘aly ‘iia acy) a “eeceond BY. ray eeRA ahi, La hove gore: eye reise 11K: me ee | : ee veal gayi: aad th > esa f Bow oe ix: i he he aa aa eh Core ore hee i ths Sarat) ae TURBINELLUS. << oe Lam.—Syst. des Anim. sans Vert. p. 83. ~< > TESTA turbinata, apertura angusta, basi canalicu- lata; Columella 3- ad 5-plicata; plicis compressis, transversis. ry A Genus approaching very neatly in its genéral characters to Murex; some of the species which constitute it have been placed by Linné among his Murices; others on ac- count of the plicated Columella he has arranged among the Volute. We apprehend the Murex Scolymus, Voluta Pyrum, Voluta Ceramica, Voluta Turbinellus, and Voluta Capitellum constitute together a very natural Genus, to which Lamarck has given the Generic appellation of Tur- binellus. ‘They are turbinate shells with a rather narrow aperture, elongated at its base into the form of a more or less lengthened canal: from three to five prominent, com- pressed transverse folds, all nearly equal in size, are placed near the centre of the Columella,; these distinguish the shells of this Genus from Murex, with which, however, they agree in having an operculum, which with the canal at the base of the aperture separate them from Voluta. The several species which we have seen are covered with a thickish horny epidermis. The Turbinellus Pyrum (Voluta Pyrum Linn.) from which our engraving is taken, has the upper part of its volutions furnished with a few rather distant, not very - prominent tubercles, but some other species are covered with several rows of very regular, rather close set, pro- minent tubercles. © In some of the species of this Genus a singular fact may be observed, which seems to prove that the plice on the Columella are of considerable importance to the animal mhabitant, and that some of the animals of the univalves TURBINELLUS. have the power of eroding or abrading or absorbing the calcareous matter which they have deposited in forming their sheils, when they have no further use for it: for three | rows of tubercles from the lower part of the whorl are gradually destroyed as the animal increases its inner lip, and in their place are formed the folds of the Columella. The Turbinelli are marine. We are not aware that any have yet been found fossil, though they might be ex- "pected in the marine strata aboye the chalk. = PANDORA. Ne Lam.—Syst. des Anim. sans vert. p. 156. fs TESTA transversa, inequivalvis, inequilatera, latere antico longiore; regularis, libera. Valva altera plana, margine antico detlexo, dente unico, oblongo, obtuso, postico, altera concava, eden- tula. dagamentum cardinis internum, cicatricule elongate in utraque valva aflixum. Impressiones musculares in utraque valva due, distantes, laterales. Suet transversely oblong, inequivalve, regular, not at- tached, inequilateral, the anterior side longer and slightly gaping at its extremity; one valve, called by Lamarck the upper valve, flat, its anterior margin turned downward, with a single, oblong, obtuse hinge-tooth placed behind the ligament; the other valve concave, without any tooth, but an indistinct cicatrice, against which the tooth of the flat valve lies when the vaives are closed. Cardinal ligament internal, fixed in each valve to an elongated cicatrice, which is inclined toward the anterior side of the shell.— Two distant lateral muscular impressions in each valve. It will soon be perceived that we dilfier very materially from Lamarck in the number of teeth attributed to this Genus. Our regard to truth obliges us to do so; and much as we lament the necessity we are thus placed under, we can assure our readers that we have not done it without a strict examination of a number of specimens, for which we are indebted to the friendship of C. De Gerville, and also that we find the characters constant in three species. The Tellina inequivalvis of Linné is the type of this Genus, it is the Pandora margaritacea of Lam. in his Sys- téme, but, without giving any reason, he has aitered its specific name to rostrata in his Histoire Naturélle; where- fore we retain the former name. PANDORA, Two species are described by Lamarck, one of which, the margaritacea, or rostrata, is frequently found on the shore at Granville, and on the coast of Guernsey; the obtusa is found at Weymouth, and in Plymouth Sound; it has been long ago figured by Pennant, as a new and singu- lar Mytilus, found at Weymouth. Mr. G. Humphrey has furnished us with a third recent species from the Kast Indies, we have named this P. flexuosa, and on account of a pecu- liarity in its internal structure, we think it deserving of a more particular notice: in this species the internal liga- ment is no longer attached on the flat valve to a mere cica- trice, but the part which bears it is produced into the form of an elongated lamina, diverging from the wmbo towards the anterior side of the shell, and reaching nearly to the inner side of the anterior muscular impression, and to the. edge of this the principal part of the ligament in this spe- cies is fixed: but in all the species of this Genus, this liga- ment might properly be said to be divided into two por- tions; the first, and generally the larger to the cicatrices in both valves, and to the anterior part, close to the wmbo, of the tooth in the flat valve; the second, and the smaller in two species, attached in the flat valve near to the anterior side of the cicatrice, and in the concave valve to the ante- rior edge close to the wmbo: in the P. flexuosa, this second part of the ligament is much the larger, and is attached as above described to an elongated lamina. Had Lamarck described this species, we should not have been surprized at his saying it had two teeth, but neither of those he has described are possessed of this lamina. We do not know a single instance of its having been found in a fossil state. Of its relations we are unable to. decide; Lamarck seems to us to have judged rightly in placing it near to Corbula, but as he has erroneously given it two diverging teeth in the flat valve, his observation, that ““ by their hinge the Pandore seems to approach the Pla- cune”’ falls to ground. its single obtuse tooth in one valve only separates it from Corbula, as its internal ligament does from the Linnean Vellina. | CORBIS.

TESTA oblonga, subcylindrica, spiré brevi, non canaliculata. Apertura elongata, basi emargi- nata, effusa. Appendix tumida et obliqua ad -basim columelle. We have no hesitation in retaining Lamarck’s original name for this Genus; partly because we wish to avoid un- necessary innovation, and further, because we think it is ety different to be easily distinguished from Miiller’s neylus. fn general form the shells of this Genus are oblong and subcylindrical, they have a short spire, seldom exceed- ing a third of the whole length of the shell, and the volutions are not separated from each other by a canal, as they are in Oliva, but the line of separation is generally hidden by an enamel-like shelly deposition which extends far beyond it, and sometimes covers the whole upper part of the shell. The aperture is elongated, wider at its lower than at its upper part, and notched at its base. The Columella is smooth, with an oblique, tumid, generally striated ap- pendage, or varix at its base. The whole shell is ver smooth and shining, and, as we believe, destitute both of epidermis and operculum. The only Genera with which this can be confounded, are Terebellum and Oliva; the striated, tumid varix dis- tinguishes it from Terebellum,; and it wants, as before observed, the canal which separates the volutions in Oliva. Only a few recent species are known, they are placed among the Linnean Voluta; but though the animal is not known, there is reason to believe, that its mantle is ex- tensible over the whole or greater part of the shell, if we may judge from their perfect smoothness. 'The small num- ANCITLLA. ber of fossil species that we are acquainted with, occur in the Calcaire grossiére, and in the London Clay; we have frequently seen one in a sort of Green sand, from near Turin. : The Ancille are marine; it did not at first occur to us that they might be confounded with Lamarck’s Mela- nopsis, a fresh water Genus, as we know they have been, particularly some of the fossil species; this latter is, how- ever, sufficiently distinct, and may be known by the tumid wpper part of its inner lip, and by the spiral line being distinct, and not covered over with a shining enamel-like coat; when recent, moreover, the Melanopsis has a strong blackish epidermis, and an horny operculum. Our Fig. 1. most nearly resembles Lamarck’s Ancilla marginata, but it has not the “ spira carinulata’’ mentioned by him in the character of that species. We believe Fig. 2. is A. subulata, which differs from A. buccinoides, in being © less gibbous. Fig. 3. is probably 4. glandiformis of Lam. PLICATULA. ee oe Lam.—Syst. des anim. sans vert. p. 132. <7-o- TESTA trregularis inequivalvis, inauriculata, basi attenuata; margime supero rotundato, subplicato ; umbonbus mequalibus; arets externis nullis— _ Cardo dentibus duobus validis in utraque valva. fovea intermedia Ligamentum omnino internuin recipiens. Tue above Generic character appears evidently to have been intended by Lamarck, to distinguish this Genus from Pecten and Spondylus, to both of which it has some affi- nity, but particularly to the latter, in which the species of it have been placed by Linné, Gmelin, and others, whose ee am plicatus may be considered as the type of the enus. The two valves in Plicatula are not alike, one being rather convex and attached by its outside, generally near the umbo, to submarine bodies; the other being flatter in most of the species, and somewhat so in all. The general form of the shell is like an oyster, without the auricles, which distinguish Pecten and some of the other Genera included in the Linnean Ostrea; the base or umbo is at- tenuated, and the opposite margin rounded, and generally more or less plaited; the wmbones are unequal, that is, the umbo of the attached valve is more produced than the other ; their points are not separated by any external area or disk, as in Spondylus. Two distinct, generally perpen- dicularly grooved teeth are seen in each valve, these have their points turned backwards, and they are so locked into each other that the two valves cannot be separated without breaking them, nor can they be opened wide without using extraordinary violence ; in the center of the hinge between PLICATULA. the teeth is a small hollow space in each valve, to which is attached the entirely internal ligament. A single, strongly marked, orbicular, muscular impression is observable near the center of each valve. Not many species are known; the recent one of which we have given a representation, is the P. ramosa of La- marck, in his Histoire Naturelle des Anim. sans vert ; why he should have altered its name from gibbosa, formerly established by himself in his Sysiéme, we know not; we should rather have retained the former name, for if we do not misunderstand the term, ramosa, as a specific name, conveys the idea of a branched shell, whereas he means it _ to describe the branched plaits of the outside of the shell. A. few fossil species are described, they are characteristic of the Lias. One found near Metz, is engraved in the Encycl. Methodique, and quoted by Lamarck as a Placuna. All those we have seen are more or less closely covered with small spines. Fig. 1 Plicatula gibbosa. 2 a younger specimen of the same, attached to an Arca. spinosa. 3 POTAMOPHILA. Ae Galathea.— Brug. Encycl. method. pl. 250. f..1. a. b. ¢. <~y oe TESTA crassa, transversa, equivalvis, subtrigona, epiderme virente induta. Dentes_ cardinales _crassi; duo in valva dextra, basi conniventes; tres in altera, in triangulum dispositis, inter- - medio minore, distincto. Dentes laterales in- - distinctissimi, remotiusculi. Lagamentum exter- num, breve, prominens, turgidum. Nymphe prominule. lmpresscones musculares in utraque . valva duz, versis basis teste excavati. WE regret that we are obliged to change the name of this Genus; this necessity arises from the circumstance of La- marck’s having employed the name of Galathea twice, in one instance to denote a Genus of Crustacea, and in the other for the shell in question; and we find Galathea, already adopted by others, as the Generic name of the Crustaceous animal, for which it claims also the right of prior application, having been adopted by Lamarck from Fabricius. We have, therefore, applied the term Potamo- phila to the shell, which will designate the predilection of its animal inhabitant for River water in preference to that of the Sea. In comparing our specimens with the Generic Cha- racter and description given by Lamarck, we find we cannot comprehend several expressions which he has made use of; the first, when speaking of the three teeth in the left valve, he says,“‘L’ intermediaire avancée, grosse et calleuse,”’ whereas, we find the intermediate of the three to be the smallest, and the least prominent; the second, ‘ Denis cardinales sillonées,” whereas, we find no grooves on the cardinal POTAMOPHILA. teeth; the third, “ Dents laterales écartées,’ whereas, in one valve we cannot find any lateral teeth, and in the other they are very obscure, and placed near the cardinal teeth; the fourth, ‘‘ Les impressions musculaires paraissent double de chaque coté,’’ whereas, upon careful examination, we find no double appearance of the muscular impressions. An equivalve, transverse, subtriangular shell, of a very thick substance, and covered on the outside with a thickish olive green epidermis, which is generally worn off at the umbones, and the shell eroded, as in most other fresh water bivalves. The cardinal teeth are thick and large: there are two in the right-hand valve, which are united towards the umbo; three are observable in the other valve, placed in the form of a triangle, the anterior of these is obliquely elongated; the intermediate one is thick at the base, and pointed at the apex, it is the smallest, and is quite sepa- rated from the other two, it fits into the cavity formed be- tween the two united teeth in the right-hand valve; the posterior tooth in the left-hand valve is the largest, it is oblong, its apex is prominent, and there is a small cavity near its base. ‘There are very indistinct daiecral teeth in the right-hand valve, which are placed not far from the car- dinal teeth; we cannot find any lateral teeth in the other valve. The Cardinal ligament is external, short, promi- nent, swollen, and the parts to which it is attached are also prominent. ‘There are two muscular impressions in each valve, which are very deep towards the base of the shell. Only one species of this Genus is known; itis the Venus subviridis of Gmel. but is very distinct from Venus ; beneath the epidermis the shell is very white, sometimes violet co- loured near the base, and marked with several violet rays. Our engraving is taken from a specimen in which the shell is colourless; the epidermis alone having some rays of a darker colour than the rest. It is a scarce shell, and highly valued by Collectors.. Lamarck says, it is an inhabitant of rivers in the island of Ceylon, and the East Indies: our specimen 1s from the river Congo; several were brought from thence, by the survivors of the late unfortunate expedition. CRASSATELLA. — TESTA globosa, aut globoso-discoidea aut disco- idea umbilicata; spird brevi; anfractibus ven- tricosis: aperturé oblonga, integra altitudine latitudinem superante ; Operculo testaceo, annu- lari, nucleo subcentrali, laterali. In introducing the Genus Ampullaria to the notice of our readers, we feel ourselves called upon to explain the cha- racter which Lamarck gives to its animal inhabitant, of being furnished with an horny operculum, for we believe that all the Ampuillarie possess an operculum as completely shelly as the shell itself, and covered with precisely the same kind of epidermis. We do this with regret, because we never intended to arrogate to ourselves the character of conchological censors, and because in the prosecution of our work we find so many errors, and so general a care- lessness in description as well as nomenclature; but we hope to do it with tenderness, feeling our own liability to error, and not doubting that in many instances we shall be obliged to claim the same degree of indulgence we would extend to others. We suppose then, that Lamarck, when he first established the Genus, meant to include in it not only the nearly globose, umbilicated shells, now distin- guished by the name of Ampullaria, but also some others” which he has since called Paludinw, and which have truly an horny operculum and are more turrited shells. Weare convinced also, that there exists a much more considerable difference between the true Ampullarie and the Planorbis, than appears from the consideration of the charaeters Lamarck has assigned to them in his Systéme, which he there makes to consist almost entirely in the discoid form ¢ AMPULLARIA. ‘of Planorbis: however, we are certain that the principal differences between the shells of these two Genera are to be found in the form of the aperture, and in the presence or absence of an operculum; for which reason we are obliged to take the shell he has given as the type of Planorbis, and add it to the genuine Ampullarie ; and this we find the less difficulty in doing, as we possess a series of speciinens of decided Ampullarie, which pass, by regular gradations, from an extremely ventricose, and nearly globose, to as nearly a discoid form, without any material alteration in the form of the aperture. We do not mean to place any reliance on the fact, that all the species of Planorbis, of which we have been able to examine the living inhabitant, prove to be constantly reverse shells, because we are aware that some of the Ampullarie are also reverse; but we are disposed to unite with Cuvier in expressing our surprize, that a fact of so great import- ance should either have been entirely unobserved or remain unmentioned by some, while others (not satisfied with dis- believing the fact) maintain a contrary opinion. The true Ampullarie may therefore be either nearly globular with a more or less produced spire, or it may be discoid, but still having a more distinctly elevated spire than Planorbis: its whorls are ventricose, and it is umbili- cated; ef course in the more discoid species the umbilicus. is larger and more expanded, so that the whorls may be counted on that side as well as on the side of the spire: the aperture is oblong, entire and longer or higher than it. is wide, whereas in Planorbis it is on the contrary rather the reverse ; in Ampullaria a shelly annular operculum, with a nearly central nucleus, placed towards the inner side, and coated by an olive green horny epidermis, exactly similar to that on the shell, closes the aperture; it is remarkable that this operculum is subject also to the same kind of erosion, commencing near its centre, which isso commonly seen near the apex and on the prominent parts of the shell itself: we think this rather confirmative evidence of an opinion which has been entertained by some, but combated by Lamarck, of the analogy of the operculum in these shells to the second valve of bivalves. Without, however, pre- suming ourselves to venture an opinion on so difficult a subject, we wish to draw the attention of Conchologists to the nature, use, and peculiarities of structure observable in opercula. AMPULLARIA. We have mentioned above the principal differences between Ampullaria and Planorbis; there are, however, some other Genera with which it may be confounded, particularly when in a fossil state, or when deprived of its epidermis and operculum, and from which it is essential to distinguish it; these are Natica and Helix, it differs from the first in wanting the spiral, shelly callus which in that genus is seen in the side of umbilicus, and which in some instances entirely fills it up; and from fedix in not having its outer lip thickened and revolute. Weare not acquainted with any considerable number of recent species of Ampullaria, all we have seen are from the Rivers and Lakes of hot climates. Olivier (Voyuge dans L? Empire Othoman, &c.) mentions one as being found in the Lake Mareotis, in company with marine shells, but all his endeavours to procure the living animal were fruitless : we hesitate to admit into the Genus another reverse species, which he calls 4. carinata, abundant in a neighbouring river, but which, if we may judge from his representation, has an horrty operculum, and should therefore rather be considered as a Paludina. We are not certain that any fossil species of this Genus _ exists: several are mentioned -by Lamarck in the Annales du Museum, among the fossil shells of the environs of Paris; others which are thought to be genuine Ampullarie are found in the London Clay at Hordwell, and in the mixed stratum between the two fresh water beds at Headen Hill in the Isle of Wight. Those we have represented are all recent species. , Fig. | Ampullaria rugosa, with its operculum; of this species the aged shells are sometimes much wrinkled. 2 The inside of the operculum of the same. 3 Ampullaria Cornu-arietis (Planorbis Cornu-arietis.—Lam. in Encycl. meth. pl. 460. f. 3. 4 Ampullaria subcarinata: a reverse species from the River Congo: we have named it from the obtuse carina which surrounds the umbilicus, i eam wate £3 56 x Sy ta henwirtage Bevis eh pesky i sink: Laing tov we ie Peery ; aily seve «sinew solidus ik 7 ¥ \ a ay Pines a, 2 ¢ OP bal : ae : sik bon | i: be paatitet G “oetbatl ¥ pd i 7 revgey zt) Sa ze ‘ix % sae 7 bey ne ce tT si tate ‘hi eet? Hebnall ud pare Dial 4 i yd 7 — patita f ' iit vi we vib | » geile ‘ a ene 8 beats oy a Pe pecans * Nae Fit Ape ave e eee). Nat Ae Pere’ as ab pny” Gris ae Gott abit sonics Hlayet ae ving ibe #. mate % PHASIANELLA. <> TESTA oblonga, levis; spiré regulari, elevata; acuminata; apertura oblonga, supra acutangula, basi rotundata: labium internum parte inferiore incrassatum : Operculum testaceum, crassum, spirale, extus convexum; spira ad basim inter- nam posita. —$——— Suet oblong, smooth, with a regular, elevated, rather ‘acuminated spire: whorls somewhat ventricose, but the spiral line not very strongly marked: the aperture is oblong, pointed at its upper part, and rounded at its base : the inner lip is white and thickened, particularly at tze _ base of the Columella: a late Conchological writer prides himself upon having discovered the true character, which, he says, had escaped all authors, that of having a salient, rather internal, but very apparent fold, running along the Columella, which, however, we have searched for very carefully, but in vain. We think it more easily distin- guishable from Bulimus, by its thick, shelly, spiral, exter- nally convex, operculum, whose spire is placed on the inside, or that side which is attached to the foot of the animal, and near its lower part. The few recent species of this Genus with which we are hitherto acquainted, are all very elegantly coloured en the outside : the Phasianella varia of Lamarck which we have represented, has of late become rather common, though it was formerly very rare, and sold at an enormous price: it is brought from the coast of New Holland, and is very variable in its colours. A small, but most elegant species is found abundantly on some of our coasts, it is the furbo Pullus of authors: we have added a representation of it to our plate. bie: PHASIANELLA. Some fossil species are found in the neighbourhood of Paris, and in the London Clay, they are all small; the principal one, Ph. Princeps, is spirally grooved on the outside, and the others have generally some remaining colour in spots as in the recent shells: their fossilized opercula are found with them. Fig. 1 Ph. varia.—Lam. 2 Operculum of the same. 3 Ph. Princeps. 4 Ph. Pullus. MARGINELLA. obo CYMBA. soe TESTA levis, admodum ventricosa, plerumque unicolor. Epidermis levis, fusca, tegmine quasi vitreo partim vel omnino obducta. Apex rudis. Spira brevissima. Columella curva, 2-3 plicata, plicis magnis, acutis. Labium externum haud reflexum. Basis profunde emarginata. Aper- tura hians. Operculum nullum. Caput grande, planum, tentaculis remotis, oculis pone tentacula positis, mediocribus. . Pallium magnum? Pes maximus. Animal ecarnivorum. | Habitat marinum in calidioribus mundi veteris (a) regionibus. Norwitrustranpine the judicious. separations from the Genus Voluta of Linné, made first by Bruguicre, and after- wards more largely by Lamarck, a careful examination will, we think, convince the zoologist that a still further division is necessary. It would exceed the limits prescribed by the nature of this work to enlarge on a subject which may, perhaps, be entered upon more minutely elsewhere. Our present intention is merely to introduce to the reader a further division of the Genus as left by Lamarck into the genera Cymba, Melo and Voluta. The student, when he comes to consider this last Genus after the proposed separations, increased ‘as it has been by the new species which have (a) Under this expression, Australia and all countries, excepting America’ and its islands, are meant to be included. At present there is no positive evidence of any species of Cyméa being found in the New World. But Captain Marryat saw at the Cape of Good Hope, two shells, which, from his description, were most probably Cymde, and which the proprietor assured him came from the Rio de la Plata. The geographical distribution of the Genus Shee above ought not, therefore, to be deemed conclusive. CYMBA. flowed in upon us so abundantly of late years, will find it sufficiently overburthened, and will be disposed to admit the probable expedience of even further divisions when the science of conchology.shall be more advanced. At present, however, the only innovation intended is the separation of Cymba, part of the Gondoliéres (Cymbiole) of Lamarck, comprising what have been called the Boat- Melons, and Velo (part also of the same section) com- prising both the simple and crowned Melons. The first of these genera.is now before us, and ap- pears. to form a natural group of Mollusca; whose shells are marked by very distinguishing characters. The shells are ventricose, light and. buoyant, floating when placed upon their backs on water, and having when so placed a boat-like appearance. Their apex is rude and without regularity of shape. They are sombre, and, for the most part, uniform in colour. They are covered with a smooth brown epidermis, which is, again, more or less coated (in some instances, as in C. proboscidalis, entirely) with a vitreous covering or enamel-like glaze, probably secreted by the mantle. The columella is uniformly curved, and, it is believed, that none of the species have hitherto been found in the New World*. The Genus Cymba contains at present six species. On an accurate inspection we shall find that the apex, which in most of them can only be satisfactorily examined * Should it be asked, why the generic name Cymbium is not adopted from Klein, Adanson, and Denys de-Montfort? it may be answered, that the term Cymbium (not to insist on the greater propriety of Cymba, as a name for de- noting a part of the Gondoliéres) was used by Adanson in the year 1757, for a Genus, which from the extreme simplicity of the structure of the shell, he places at the head of the univalves, and which, under no system, could be deemed even an approach to a turbinated shell with plaits on the pillar. Denys de Montfort (in 1810) uses Cymbium to designate shells of which he makes Voluta Ethiopiea, Auct. (the only species mentioned by him,) the generic type. Klein, — it is true, calls Adanson’s Yet “‘ Cymbium,’’ but Gualtieri had used the word in | 1742, (eleven years before Klein published his ‘‘ Tentamen,”) as a generic name for those Mollusca, afterwards. called drgonaute by Linné, who appears to have first bestowed the latter name on the Paper Sailors. si It- may be added that De Blainville in his ‘* Malacologie” figures Cymba Cymbium (V. Cymbium, Auct.) as an illustration of De Montfort’s Genus; and we. therefore suppose that al? the Gondoliéres of Lamarck are. considered to be-. long. thereto. De Montfort gives the following as one reason for dividing. his, Genus from the Volutes ‘‘Le mamelon de leur coquille est particulier.”’. Ar glance at the apex of Cymba Neptuni, and that of Melo Indicus will shew their striking difference. The apex of one is a shapeless, mass; that,of. the; other is regularly and beautifully fashioned. CYMBA. in young shells, becomes progressively less rude and more firm, till in Cymba Cymbium (V. Cymbium, Auct.) it takes the form of a smooth button.or nail. head; and, on arriv- ing at this species, we have, for the first time variety of colour in the full grown shell, though obscurely clouded and ill defined. Lamarck refers to Adanson’s figure of I’ Yet for our Cymba Neptuni (VP. Neptuni, Auct.) and though Linné refers vo the same figure for his V. Cymbium, there can be little doubt that Lamarck is correct in his reference. Our description of the soft parts is taken from Adanson. The animal is carnivorous, and is eaten by the natives of the coasts where it abounds. We are not aware that any of the shells of this Genus have been found in a fossil state. | Fig. 1. A young shell of C. Neptuni, (Voluta Navicula, Gmel. for this is one of the many instances of the difference of age being mistaken for specific difference,) showing the amorphous apex, which inold specimens becomes entirely concealed. 2. C. Cymbium. 3. A small but old shell of C. proboscidalis, the apex entirely concealed, and the whole shell covered with the enamel-like glaze. For the descriptions of this and the following Genus, Melo, the public are indebted to W. J. Broderip, Esq. who has also kindly engaged to furnish the description of Voluta. This gentleman’s polite compliance with our request, that he would assist us inthis part of our labours, has obliged him to anticipate in our work some parts of his own monographs of the Genera Cymba, Melo, and Voluta; thus increasing our obligation to him: an obligation which, how- ever, we are the more willing to incur, because we are fully assured that from the extensive collection he has brought together in illustration of the species, and his intimate acquaintance with the subject, he is the only person capable of doing it justice. l 3, fsbaraks Aa Pol pe we ATS ho some pila toga mit , piu nifaP ai mi some bie Levin % #8 a att oe ees thy a | SEE isis eg bijodayi, an at “Al Fon ee 2, Ris a iad 4, ii ‘fe las: sale ‘ds i ions J sai sitet too eae tate NG gamely qi m i Ne tte BU Be tr me Seat ehe arin nat Lialhiwhighie:t radu “ore, Diahtea: 3 ft ksh UR iid gy Ue gery a pays pee ee yg oe) YR “eee WY) atoniyl Vi RSG 8 detst Ch nyt Hy A aa Ra A ye. ene ht Mai ¥ a Hoty Ak wo Wo’ Wiese? CATOPHRAGMUS.* a a oa TESTA subconica, apice pervio, basi adheerente, _.(valvd, testaced clausd?) valvis octo, inequali- bus, lateraliter adjunctis, composita; valvis . porro plurimis per series externas, circulares, _gradatim minores, confertim co-ordinatis. ~Operculum bipartitum, valvis quatuor, anticis majoribus, compositum. eee We have ever been anxious to avoid increasing the number of genera as much as possible, not, indeed, be- cause we entertain the impression that by so doing we should increase the difficulties attending upon our fa- _vourite pursuit; for, on the contrary, we are persuaded that an increase in the number of genera, where there are sufficient distinguishing characters, would materially lighten’ the toil of the student. Our reason for this anxiety has rather been the want of preparation in the mind of students to profit by such improvements as have been and might be daily introduced. The sort of prepa- ration we mean is the adoption of correct first principles, upon which alone, as on a foundation, a symmetrical and beautiful system can be established. That these correct first principles are only to be obtained by the study of the Moliusca, which form and inhabit shells is becoming daily more and more apparent, yet the shells themselves may in most cases be regarded as indicating many of the more important facts in connection with the history of their animal inhabitants, and may consequently be gene- rally considered as sufficient to demonstrate’ characters strong enough for the establishment of genera; with these views therefore we do not hesitate to propose the present new Genus, which, without knowing the animal, yet from analogy, we judge to belong to Leach’s “ Cirri- pedes acamptosomata,”’ the ‘* Cirripédes sessiles’’ of Lamarck. ° ‘ * From %27Tw infra et Ppaypros septum. CATOPHRAGMUS. in its general form and appearance it closely resembles “< Octomeris,” a Genus which we lately thought it our duty to propose, and, as in that Genus, the shelly eone immediately surrounding the animal, consists of eight pieces, and its operculum is also composed of four pieces. Here, however, the particular resemblance of the various parts cease, and we have now to describe the peculiarity of our present new Genus... This peculiarity consists in a number of narrow perpendicular valves arranged around the above mentioned shelly cone, and in rows, like pales, the first row of which consists of eight pieces, placed so as exactly to cover the sutures of the shelly cone immediately surrounding the animal; around this are then placed several sets of more and more numerous pieces gradually decreasing in size, so that the outer row which is the most numerous consists also of the smallest pieces. Additional rows seem to be produced as the animalincreases in age; for a young specimen in our posses- sion has only one row of eight pieces covering the sutures of the first cone, while a much larger and older specimen — still retains part of three rows, and has evidently lost some of the external rows. The young individual also shows that the whole of the pieces are pointed at their superior extremities, whereas, in the old shell these ex- tremities are so worn or eroded as to become very irre- gular and obtuse. The valves of the operculum are also pointed. | We do not observe any epidermis, though there is probably a very thin one on those parts that are not worn.* | Two specimens only of this singular Cirripéde have come into our possession; one of these was fuund in the collection of the late George Humphrey, and the other is attached to a Conia, which we received from Antigua. In our plate we have represented, at Fig. 1. The young specimen of its natural size, upon the kase of a Conia. 2. The young specimen magnified. 3..& 4. Two views of the old shell, natural size. 5. & 6. The same views, magnified. * We are glad to take this opportunity of correcting an error into which we have fallen, in stating Balanus not to have an epidermis. We believe when in their natural state the shells of that Genus always have a thin horny epi- dermis. MELO. ny TESTA ventricosa, levis, ut plurimtm colore vario. .Epidermis levis, viridi-fusea. Apex mamillaris. Spira brevis. Columella vix recta, 3-4 plicata, plicis magnis, acutis. La- bium externum haud refiexum. Basis pro- -funde emarginata. Apertura hians. Operculum nullum. | Low Caput grande, planum, tentaculis lateralibus, remotis, oculis pone tentacula positis, magnis. Branchie satis magne, dextra major. Pallium mediocre. Pes maximus, ovalis. Animal carnivorum. 4 F Habitat marinum in calidioribus mundi veteris regionibus. THE apex, which, in Cymba, was almost a shapeless mass, takes in Melo a well-fashioned and spirally marked form. With this first appearance of the mammillary summit begins the elegant and vivid colouring which is its almost constant companion. The suture of the spire, no longer rude, is either neatly laid down around the apex, so as to touch it, and in some instances overwrap it, or, as in the coronated section, is free and adorned with a diadem of vaulted spines. The shell of Melo is ventricose, light, melon-shaped, and floats when placed with its back on the-water. It is generally marked with a well defined variety of colour, and covered with a smooth greenish brown epidermis,* * Lamarck speaking of his Genus Voluta, says {“‘ Les espéces sont en général lisses, brillantes, et it ne pardit pas qu’ aucune d’elles soit powrvue d’un drap marin.” The writer who has ventured to propese these new Genera hopes to be enabled fo shew that most, if not all, of Lamarck’s Genus Poluta, are provided with a ‘‘ drap marin.” MELO. which is in some species very thin, but always wants the glazed coating of Cymba. The apex is mammillary, and looks almost as if it had been turned in a lathe. The pillar, which is hardly straight, has from three to four plaits sharp and well developed. The edge of the outer lip is not reflected, the base is very deeply notched, and the aperture, which is unprotected by any operculum, is very wide. The Melons, some of which grow te a very large size, are inhabitants of the warmer regions of the old world. Weare indebted to M. Freycinet’s beautiful work for a figure and description of the soft parts of Melo LEithiopicus, (V. Asthiopica, Auct.) which was found in Sharks’ Bay, and is carnivorous. Section 1.—Spira inermi. Melo Indicus, (V. Melo, Auct.) ’ 2.—Spira spinis fornicatis armata. Ex. Melo 4thiopicus. Of the first section there is but one species known: of the second there are six. None of the Genus appear to have been discovered in a fossil state. Fig.1. A young shell of Melo Indicus, (V- Preputium, Chemn. Gmel.) 2. A full grown, but not large shell of Melo Indicus, covered with its epidermis. 3. Melo umbilicatus, (Broderip,) N.S. in an intermediate stage of growth. In the full grown shell the whorls of the spire and body whorl project so much beyond the apex, that the latter is seen as it were at the bottom of an excavation. PULLASTRA. Venus, Pars, Lam. Venerupis, Lam. — oo TESTA eqgquivalvi, transversa, inezquilaterali, -latere antico breviore, dentibus cardinalibus in utraque valva tribus contiguis, interdum ‘apicibus subemarginatis. Impressiones muscu- _lares due, laterales, subrotundate. Impressio “muscularis pallii sinu magno. Ligamentum externum, valvarum marginibus dorsalibus . suboceultatum. To say that Linné himself, could he have lived till the present time to know what we know, and to see what our eyes every day behold of the habits of the mollus- cous animals, would have acknowledged the necessity of establishing many of the new genera that have been founded since his time, is not to offer a very high compli- ment to his judgment as a naturalist. We go much further, for we say that the most bigoted of his followers, few of whom can suffer the establishment of a new Genus because not founded by Linné, can neither avoid being convinced of the necessity of several dismemberments to which the Linnean Genus Venus has already been sub- jected, nor deny the necessity of further subdivision. We have scarcely yet meddled with that intricate Genus, PULLASTRA. and we now intend to confine our remarks more par- ticularly to a small part of it, which has not yet been separated from it, except by Bruguiére of whose Capsa the Genus we are now about to treat of forms a part. Lamarck has, indeed, constituted his Venerupis of a part of our Genus, but the greater number of its species are by him still left in Venus. The difficulty of ascertaining any distinguishing character between the Lamarckian Venerupis and the Veneres, Pullastra, decussata, and others, except in the apparent habits of the animals, has prevented us hitherto from endeavour- ing to clear up a point to which our attention has fre- quently been directed, but which we now think we have overcome. It is well known that Venus perforans, Mont. Venerupis perforans, Zam. and some of its congeners live in cavities perforated in chalk and limestone rocks, and that the Veneres Pullastra, decussata and several other species that resemble them in general form and appear- ance are found buried in the sand; an apparently well marked difference therefore exists in the habits of their respective animals: we think, however, that we have evidence to prove that there exists in reality very little difference, and that the cavities in which Lamarck’s Venerupes live, arerather the natural consequence of the action of the sea water in conjunction with some of the excretions of the animal upon the chalk or limestone, than of any power of the animals themselves to pierce, independently of such action: so that the difference is really only in the nature of the shore on which the very young shells are accidentally deposited, those which are thrown upon a sandy bottom, burying themselves in the sand, and such as are deposited upon limestone or chalk producing a cavity in which they live. © — The shells which we now propose to unite together under one appellation are Lamarck’s Venerupes, and the following of his Veneres, viz. V. Malabarica, papilionucea adspersa, punctifera, turgida, litterata, sulcaria, Textile, texturata, geographica, rariflamma, decussata, Pullastra, aurea, virginea, and some others: and for the Genus thus constituted we propose the name of Pullastra, rejecting the term Venerupis or Venerirupis, because it would convey the false idea that at least the greater number of the species were inhabitants of rocks. = 4 PULLASTRA. Shell equivalve, transverse, inequilateral, the ante- rior side being the shorter. Cardinal teeth three in each valve, placed near to each other, and generally having their terminations notched; in a few species the central tooth of one valve is deeply cloven. Muscular impres- sions two, lateral, roundish. Muscular impression of the mantle with a large sinus. Ligament external, partly concealed by the dorsal margins of the valves. Several recent species of this Genus are common on our own and other European shores; others are brought from the East and West Indies; some are beautifully marked. Fossil species are scarce, and we believe are only found in the tertiary beds. $9, 17} 1 af sobaaee 1s anidveuté. fei we hte OLE Agvetitioponi ek ood? diac Lanthuad iiaa vy cine ‘qlittomey) ‘bow. ihn | Lie tte ese aah Raby ey ferret sebeertt * inn i tne Be core ates Ma mic) stich biel ont ha a Niet ih pote wi snhentdti”y der hthe "tt vine aed “om 919.08 pepkial se 4 av aul ings ove el al fiona 916 , 1 Gi ae y TEREDINA, | Lam. ' see TESTA crassa, fistulosa, antice sensim attenuata, aperta, apertura dissepimento subdivisa, oper- culo unico nonnunquam occlusa, postice omnino clausa, valvis duabus (ut in Teredinibus con- formatis) in externo tubi pariete conferrumi- natis, intus dente recurvo majore instructo; valva aeccessoria subquadratdi umboni antice superimposita. | —— A very singular Genus only known in a fossil state, be- longing to the Zubicole of Lam. and approaching in its characters to Zeredo. In consequence of its general resemblance to that genus, we were at first disposed to have united them together, joining to them the Fistulana gregata of Lam.; but as the tube in Zeredina never covers the two valves, but appears to be soldered to them, as in Aspergillum, we are constrained to regard it as a dis- tinct Genus ; of which, however, we only know one species at present, namely the TZ. “personata of Lam. for we have already ventured to express our opinion that the shell des- cribed by Lam. under the name of 7. Bacillum is not a Tere- dina, but may more properly be considered as a Sazicava. In many respects Teredina personata resembles the Pholas papyracea of Turton, and in others the Pa. striata of Linn.; from the latter, however, it differs in having a shelly tube which that has not, and frum the fermer in having an operculum to cover the posterior aperture of the tube. Shell consisting of a thick fistulous tube, smaller at the posterior end, which is open, nearly divided into two by a projection on each side within, and has an operculum, as we are informed, though we have never seen it, which covers the double opening: it is remark- able that the posterior smaller portion of the tube is of a very different substance and colour from the anterior and larger termination; it resembles horn in appearance i78. TEREDINA. while the anterior part and the two valves are like a soft shelly substance. In form the two valves exactly resem- ble those of Teredo; in Teredina, however, these are wholly external, and they are thickly lined as well as united to the tube by a continuation of the shelly matter of which the tube itself consists. The beaks or umbones of these two valves are very much incurved, and covered by a rather quadrangular thick accessory piece which appears to be fixed to the valves in front of the beaks; and there is an irregular prominence of the tube just behind the beaks.. The anterior termination of the tube is completely closed by a trapezoidal piece which fills up the space left by the sinus in the two valves. The testa- ceous matter is generally so much increased in thickness internally, as nearly to obliterate or cover the internal appendages usually called the teeth, common to it and Teredo. ! The Teredina appears to have been gregareous, as it occurs in numbers in a bed of ferruginous sand at the only place in which it has been found; there is no reason to doubt its habit of living in cavities of its own tere- brating, but whether in wood or any other substance, we have not the means of ascertaining. That in its young state it is destitute of a tube, and consists only of the two valves and a membranaceous envelope we cannot doubt, and it appears to us probable that in this respect as well as in the habit of terebrating sandstone it is nearly analogous to the Pholas papyracea.* Fig. 1, Teredina personata, showing the ventral portion together with the double aperture. 2. The form of the aperture 3. The dorsal portion showing the beaks. 4. The same having the beaks covered with the accessory valve. * For notwithstanding the opposition which our opinion formerly expressed has met with, we must still maintain that the Ph. damellata of Turton is only: the young of Ph. papyracea. Ue XYLOPHAGA. —p he TESTA orbicularis, zquivalvis, inzquilateralis, anticé hians, (hiatu posticé angulato) valvis accessoriis duabus, subtrigonis, fornicatis, ‘dente cardinali minuto et costa, in utraque - valva, interna ab umbone ad marginem basalem decurrente; impressionibus muscularibus binis, postica magna, obovata; anticd minore, margint superiore imposita. ———— _ We are obliged to Dr. Turton for his very liberal com- munication of several specimens of this new and very interesting Genus, as well asfor the discovery and first description of it. A single specimen has also occurred in a piece of stick thrown up at Gravesend, for the use of which we are obliged to Mr. Crouch. The two valves approach very much in form to those of Teredo; there are, however, two or three characters by which Xylophaga may be distinguished from that Genus; these are, the want of a shelly tube and of those internal appendages common to Pholas and Teredo, gene- rally called teeth, and the addition of two small accessory valves; it appears also to be destitute of the spatulate opercula found in the Teredine. Shell nearly orbicular, equivalve, valves inequila- teral, gaping in front, the opening having an angular termination at the back. Two small, rather triangular, calyciform accessory valves are placed over the anterior side of the hinge, and there is a small curved tooth lying close to the umbo within in each valve; as well as an internal rib running from the beak to the basal margin with a corresponding depression on the outside. The posterior muscular impression is large and obovate; the XYLOPHAGA. anterior smaller, placed on the superior margin close to the beak. This Genus, of which only one species is at present known, pierces wood, to the depth of from half an inch to an inch, where it forms a clavate tube, without any lining; and as we are informed by Dr. Turton, its animal fixes itself by a fleshy disk to the lower part of the tube. We think, that on account of its having anterior acces- sory valves, and its not being possessed of the two oper- cula and the shelly tube, it must be regarded as more nearly related to Pholas than to Teredo. j The specimens sent. to us by Dr. Turton were dis- covered in a part of wreck dredged up near Berry Head. VOLUTA. =o TESTA subovata, coloribus plerumque variis eximié picta. Apex papillaris. Columella plicata, plicis inferioribus maximis, basi emar- ginata. Epidermis tenuis, fusca. Animal carnivorum. Caput tentaculis 2 in- structum. Oculi ad tentaculorum basin ex- ternam appositi. Pes maximus. Opereulo caret.* | | Habitat marinum in calidioribus mundi ve- teris regionibus, rarior in Indis oceidentalibus. SHE. inclining to oval, elegant in form, and, in the ma- jority of species, beautifully pencilled with variegated colours. Apex of the spire papillary, more solid than that of Melo. Pillar plaited, (the lowest plaits being the largest, and most oblique,) and notched at the base. Epidermis thin, varying from greenish to brown. ) Animal carnivorous. The head furnished with two tentacula, at the external bases of which are the eyes. Foot very large. No operculum. 0 Inhabits the seas of the warm countries of the old world; and is found, but much more rarely, in those of the new. lt There is reason to believe that the genera Cymba, Melo and Voluta are viviparous. Fossil species of the latter genus occur, above the chalk, in the crag, in the London clay and in the calcaire grossier at Grignon, Courtagnon, &c. In the chalk no trace of the genus has, I believe, been noticed: and, below the chalk, it appears to have been only observed in the Cornbrash.+ * { have had no opportunity of examining the soft parts of a Voluta, but the gradations from the shell of Melo to that of Voluta are se gentle, that Ihave little hesitation in giving the above as the leading characters of the animal. t See Conybeare and Phillips, part 1, p. 2190. VOLUTA. The animals characterized by Linné as Volute, form rather a heterogeneous assemblage. Mollusca whose branchial system allows them to respire nothing but wa- ter ;—others which breathe air, and to which submersion in water for any length of time would be fatal ;—animals phytiphagous and carnivorous, terrestrial, fresh water and marine—will be found ranged as. ronecnaye in the Systema Nature. But the student must pause before he censures one to whose zeal and acuteness we owe so much. Con- sidering the dim light by which Linné studied Nature, we cannot withhold our admiration of the grandeur of his mind and of the monument which it raised... Had this great man been acquainted with the habits and com- parative anatomy of the Mollusca, it would hardly have been left first to Bruguiére, and afterwards to Lamarck to reform the genus Voluta. What was dark to him, modern discovery enlightened for the later phi- losophers: they have convinced us that the light did not shine in vain; and to them we owe a distribution of the Linnean Volutz into genera, which appear to form more natural associations. The genus Voluta of Lamar ck, has been still further reduced by the author of this sketch, by taking from it the genera Cymba and Melo; and the crowd of species which are still ranked under our genus will, it is sub- mitted, afford to those who study the subject, pregnant evidence that even a further division will soon be called for. Take, for example, Voluta imperialis and V. lyri- formis, and we shall find some difficulty in satisfying the enquirer that they are species of the same genus. In the present state of the science, it is however only proposea thus to subdivide the genus: | % Papillé grandi, levi, Coronate Exemp. Voluta imperialis, (Icon. Encyc. Method. tab. 382. fig. 1.) B Inermes. Bea V. Scapha (Encyc. Method. tab. 391.) VOLUTA. WE Papilla tuberculata. Vespertiliones. ' Exemp. V. rutila, (Icon. Zool. Journ. vol. II. tab. 3. KK Papilla levi, mediocri, subacuta. Ventricosiores. Exemp. V. marmorata, (Icon. Swainson, Exotic Cench. part, 1.) p Graciliores Exemp. V. Lapponica (Icon. Encyc. Method. tab. 381. fig. 3. a. 0.) ‘ Y Musicales. . Exemp. V. Musica, (Icon. Encye. Method. tab. 380, fig. l.a. 6.) KKK AS Papilla truncato-papillari. Mammillares. Exemp. V. papillaris, (papillosa, Swainson,) Icon. tab. nost. | RR RE Papilla acutiuscula. Mitriformes. Exemp. V. lyriformis, (¢ Mitralyreformis, Swainson,) Icon. Zool. Ill. tab. 54. Zool. Journ. II. tab. 4. fig. 1. + Mr. Swainson first described the two last mentioned species; and the slight alterations here given in the trivial names, are only to be considered in the light of corrections of the press. The latter shell is figured and described in the Zoological Illustrations as a Mitra; but Mr. Swainson has expressed to me, since that publication, his conviction that the shell is a Volute; indeed the increased size ef the lowest plaits of the pillar puts the matter out of doubt.— See Zool. Journ. vol, IIf, p. 83. W. J.B. | | | aang ea are AL : . eesti evert bh = ( sigeminn © ahi is isis ob “Hid a yin a Bain wit a faye: wh TEREDO. =i) TESTA orbicularis, equivalvis, inzequilateralis, utraque extremitate hians, (hiatu antico posticée angulato, altero antice rotundato) anticé suba- lata, impressione musculari antica ale imposita; dente elongato, sub umbone interné recurvo: tubo postico, accessorio, longissimo, calcareo, anticé raritis clauso, plerumque apertura ro- tunda, posticé in tubos duos diviso, operculis -- duobus palmatis, aliquando pennatis instructo. ee In our last number we considered ourselves obliged to establish three new Genera, at the same time expunging one of those formerly published by Lamarck, so that in reality we only added two to the Lamarckian list. In the 26th number we expressed our opinion that Lamarck’s Fistulana gregata might be added to his Genus Terediza, upon amore careful examination we are now disposed to abandon that opinion, and to unite Lamarck’s Sepéaria, together with his Fistulana gregata, with Teredo, thereby lessening the number of genera by one because we dv not think there exist any characters by which they can be distinguished ; which we will endeavour to show by a recapitulation of the characters in which Lamarck makes their distinctions to consist, together with our rea- sons forregarding them as inconclusive. Teredo, accord- ing to Lamarck, has a flexuous, cylindrical, shelly tube, open at both ends, distinct from the shell, and covering the animal; and its shell consists of two valves, placed without the tube at the posterior extremity. The charac- ter of Lamarck’s Septaria are, avery long shelly tube, gradually attenuated towards the anterior (which should be posterior) part, and divided interiorly by several, TEREDO. mostly incomplete, vaulted septa; its anterior (posterior) extremity being terminated by two other, more slender tubes, which are not internally divided. Thus we find that in the shelly tube itself, and in the position of the two valves with respect to that tube, his descriptions of the three genera accord; and that his dependence for a cha- racter to distinguish Septaria from Teredo is placed upon the vaulted septa of the former, which, however, to our certain knowledge, oceur more frequently in Teredo than in Septaria. With regard to Lamarck’s Fistulana gre- gata, it appears te us to differ from his. descriptions of Teredo and Septaria only in having the lower end ef the tube closed; in this regard, however, we shall find that it disagrees neither with Septaria nor Teredo, both of which occasionally close the lower end of the tube; for particular proof of this fact we refer to Mr. Griffith’s and Sir Everard Home’s papers on the subject in Philosophi- cal Transactions for 1806, part 2; where also. will be found a detailed anatomical description of the animal. The always more or less double posterior aper- ture of the tube, closed in different species by variously formed double opercula, together with the resemblance in general characters above pointed out, seem to us there- fore sufficient reasons for uniting Fistulana gregata, and the Septaria of Lam. with Teredo; of which we shall now give the generic character. | 0s SB Shell orbicular, equivalve, inequilateral, with a subalate process in front, gaping at both extremities, the anterior opening angular at the back, the pesterior rounded in front. Anterior muscular impression placed. upon the subalate process. An elongated tooth is con- spicuously seen curved out from under the umbones within each valve. With this shell, which contains. the anterior extremity of the animal, it perforates wood in an irregular manner to a considerable depth, lining the perforations as it proceeds witha calcareous, proportion- ately elongated, accessory tube, which is seldom. elosed anteriorly, but has for the most part a round aperture, and which is divided posteriorly into two tubes, which can be closed at the will of the animal by two palmate, sometimes pennated opercula. MULLERIA, De Ferussac. << TESTA irregularis, inequivalvis, ineequilatera- lis, foliacea, ostreiformis, valvaé altera externé fixda; impressione musculari unica, prope extre- mitatem posticam (i.e. dorsalem) posita; zm- pressione musculart pallii irregulari: ligamento dorsali elongato, externo, in sinum posticum decurrente: umbonibus anticis, sublateralibus. ome a One of the most singular and rare of known genera, not noticed by Lamarck, and only very recently remarked by De Ferussac among the specimens of /Btheria, in the Duke of Rivoli’s collection. The two specimens that exist in Paris, and the individual in my Brother’s collection, being all that are known at present. The Genus is remarkable as being intermediate in its struc- ture, between AMtheria and Ostrea, and as apparently connecting the regular fresh water bivalves (“the Naiads’” of Lam.) with the irregular marine bivalves, (Ostrea, for example,) and with the genus Mtheria, in- asmuch as in the sinus at the posterior extremity of the ligament it resembles the Naiads and the theria; and in its single muscular impression, as well as its general form it approaches to Ostrea. The following are the characters of the Genus; it is an irregular, inequivalve bivalve, adhering by the outside of one valve: the structure of the outside of the shell is foliaceous, but the foliations are closely pressed, and do not form any murications or other rugosity on the surface; the inside has a thin pearly coat of a glaucous green colour, and partly iridescent. It has only one muscular impres- sion in each valve, which is placed near the back and towards the posterior extremity, and from one corner of MULLERIA. which passes the muscular impression of the mantle, to- wards the anterior part of the shell: in our specimen the muscular impression of the mantle is irregular and in- distinct. The ligament is rather elongated, external, its posterior termination, however, fills a sinus in the edge of the shell, apparently formed to receive it, and in this respect it approaches very closely to the Naiads, while it | differs materially from the Ostrea. The beak is rather pointed, anterior and lateral in our specimen. A dull yellowish brown epidermis covers those parts of the shell which have not been exposed to attrition. DOLIUM. : : El TESTA subovalis, ventricosissima,. tenuis, ple- rumque transversim costata vel sulcata, spira brevissima, apertura maxima, in canalem bre- vem, reflexam desinente; labio externo sepius tenul, interdum margine reflexo, crenato: epidermide tenuissima, cornea, induta. Onw of the best marked Genera that has been established, for though it is not difficult to recognize its immediate general relation to Cassis, it is, nevertheless, easily dis- tinguished from that, and we do not know any other Ge- nus to which it bears a near affinity. It is true it resem- bles Harpa in general form, and has been arranged toge- ther with that and Cassis among the Buccina by Linneans ; the differences, however, are so great that there can be no danger of their being confounded. We regret that we have never seen the animal of any of these three Genera, it is, however, more than probable that they will be found to accord very nearly in their characters with the Buccinide. We are of course ignorant whether vr not they have an operculum. The species of the Genus Dolium are of an elliptical shape, nearly approaching to globular, being exceedingly ventricose ; they are thin, even when very large; on the outside they are always more or less strongly ribbed or grooved, the ribs or grooves being transverse to the apex ; ‘spire very short, its apex when complete being in general semitransparent, of a yellowish colour and apparently different substance from the rest of the shell. Aperture very large, terminated at the base by a short reflected canal, Outer lip mostly thin, sometimes, however, it has DOLIUM. a thickened, reflected and crenated edge. A thin, horny epidermis generally covers the outside of the shell. The species of this Genus are not numerous, nor are they rare; some of them grow to an enormous size, and they are then handsome ornamental shells. Fossil species are very uncommon, nor can we with certainty assert their existence. There is in the chalk a shell having nearly the general form of a Dolium, but its characters are not sufficiently developed in the specimens we have seen to enable v us to judge with certainty. TEREBRA. nates TESTA elongata, subulata, anfractibus nume- rosis, gradatim majoribus, apertura brevi, oblonga, iv canalem brevem, rectam desinente; columella contorta, spirali: operculo corneo, non spirali. TuovGu it may be difficult in some instances to establish the distinctions between the Terebra of Bruguiére and Buccinum, it may nevertheless be convenient to retain it in the list of Genera, because, for the most part, the species composing it may be regarded as forming a very well marked natural group. It is not difficult to distin- guish the Zerebre, (Vis of the French, Needles of the English Collectors) at first sight from the Turritelle, which they closely resemble in general form, by the short canal at the base of the aperture, and by the more or less twisted columella. The operculum also is very dif- ferent, being rather thick, oblong, somewhat pointed at the base and not spiral; whereas that of Turritella is thin, nearly circular and spiral. It is seldom, however, that this character can be brought to our aid, as the opercula of the Terebre are rarely preserved. It is not, moreover, certain that all the shells that have been ad- mitted into the Genus are furnished with an operculum, fer Lamarck asserts, as he says, upon the authority of Adanson, (though we cannot find any expression in Adanson in support of this assertion) that this Genus has no operculum. This assertion, however unsupported by the authority referred to, may perhaps refer to some Species which seem to be peculiar to the African shores, and which we think might with propriety be separated from the Terebre. Shell much elongated, subulate, sharp-pointed, in. general composed of a considerable number of volutions, TEREBRA. which increase gradually in size; aperture seldom exceeding one-third of the length of the shell, for the most part much shorter, oblong, with a short straight canal at the base: columella oblique and spiral or twisted, often striated. The recent species of this Genus are numerous, we possess about an hundred; some of them are very beauti- ful: they are principally brought from the East.and West Indies, and from South Africa: very few are European. Several fossil species occur in the newer formations, at Piacenza, Bordeaux, Turin, &c. they are more scarce in the London clay. FASCIOLARIA. | TESTA elongata, fusiformis, spira longitudinem eanalis equante; canali elongato, recto; basi eolumelle plicifera, plicis tribus vel quatuor, obliquis, inferioribus majoribus; operculum corneum, ovale, inferne acuto. One of the genera which was formerly united with Murex, but apparently separated from it with propriety: and easily distinguished by its spire and canal being nearly of equal length and by its being destitute of varices. From Fusus, however, it is not so easily distinguished, being of the same general form and having nearly the same ex- ternal appearance ; the want of oblique folds at the base of the columella in Fusus is the only character in which they differ: in Fasciolaria, these foids are very oblique, three or four in number, and the lower are the larger; we must not, however, omit to mention some shelis which may be confounded with Fasciolaria, and which, on account of their having some small folds near the base of the columella, have apparently caused much difficulty, some of them having been placed in Turbinellus, others in Fasciolaria, and others in Fusus; and having also been occasionally transferred from one to another: the folds in these are very small, and they are moreover horizontal; we would suggest the propriety of uniting the shells possessing these characters, should they be found to agree in other particulars, under a new generic appellation. The genuine Fasciolarie may be distinguished from the Turbinelli also, by the obliquity of the folds and by the circumstance of the lower being the larger. Shell elongated, fusiform, with its spire generally equal in length to the canal which is produced and nearly straight, with three or four oblique folds at the base of |S, FASCIOLARIA. the columella, the lower being the larger. Operculum horny, thickish, of an oval shape, pointed at the inferior extremity. | The recent Fasciolarie are not numerous, the East and West Indies, however, furnish several species which are rather handsome shells. The F. Tulipa, which is one of the most beautiful, is not uncommon among the West Indian Islands. In delicacy and beauty of colouring there are few shells that exceed the F. distans when in fine condition. The F. aurantiaca, which we have figured is one of the most remarkable as well as one of the rarest. All the species we know are marine, and furnished with an epidermis. Fig. 1. Fasciolaria aurantiaca. 2. Operculum of the same. MUREX. met eo TESTA oblonga, subturrita, spira plerumque prominula, apice acuto; varicosa, varicibus tribus vel plurimis, plerumque digitatis, vel muricatis, vel spinosis, vel fimbriato-laceris; apertura suborbiculari; columella levi; canali longiusculo (nonnunquam longissimo) interdum recurvo; operculo corneo. | Tue great diversity of character observable in the nume- rous shells which compose the Linnean Murex, and the consequent impossibility of constructing a character generis that should identify all, has naturally led to the separation of several kinds of shells from it, when their characters were sufficiently distinct to admit of definition, such for instance as Cerithium, Ricinula, Triton, Fusus, Ranella, &e. These curtailments have necessarily rendered the defini- tion of Murex much more easy and precise; the Makers of Genera have not however been satisfied, but have seen characters sufficiently strong in their opinions at least to raise to the rank of genera, the M. Haustellum on account of its remarkably elongated canal; the M. tenuispinosus on account of its long slender spines running in three rows down its lengthened canal, and others; we cannot however approve of such innovations, because we think their object is fully attained by the division of the genus accord- ing to the various types at present contained in it; not that _ We mean to say that every species enumerated by Lamarck under the Murex is properly so placed, because we are aware that some of them belong to other established genera; these of course should be struck out from among the Murices and restored to their proper places wherever they may be found; if however upon such circumstances MUREX. as we have mentioned above, we are to be authorized to establish new genera, we are convinced that the number of genera would shortly become equal to that of species. We would now limit the genus Murex to those species with a more or less oblong, subturreted shell, a generally rather prominent spire with an acute apex, and three or more rows of varices that are more or less digitated or muricated or spinose, or with an irregularly foliaceous or lacerated fringe ; a suborbicular aperture, a smooth columella, a generally lengthened, sometimes very long, frequently recurved canal, and an horny operculum. The characters in which these will be found to differ from those other genera which have been united with Murex are as follows: they may be distinguished from ¥asciolaria and Fusus in the general form, and in being furnished with muricated varices which those two genera have not; from Triton in the smooth columella which in Triton is rugose, and in the number of varices, which in Murex are never less than three; from Ranella because that genus has only two rows of varices, and rugose a columel- ja; from Ricinula, in general form and in their lengthened canal; and from Cerithium in the proportion of the spire which in this latter genus is much longer than the aperture. We think that Lamarck should not have admitted the M. magellanicus and M, lamellosus among his Murices, because they ratber belong to Fusus, being sometimes free from varices, which are never muricated: they agree moreover in their other eharacters more nearly with Fusus. His M. crispatus is probably a Purpura. The species of the Genus Murex are numerous, many of them are very beautiful and singular. The longpointed and regularly arranged spines on M. tenuispinosus, Lam. (commonly called Venus’ Comb) renders it an extremely interesting and delicate object: M. Scorpio is remarkable for the dilated apices of its fronds; M. Radix for its fine black short spines; M. regius for its brilliant crimson coloured aperture; M. Cervicornis for the forked points of its larger fronds; M. Palma-rose for the delicately tinted tips of its finely toothed fronds; and M. Haustellum for its uncommonly lengthened canal: these are mostly tropical species, but the genus is found in all countries: it is marine and is naturally furnished with an epidermis, MUREX. though this is communly cleaned off before these shells come into the market. Of Fossil species there are also many generally be- longing to the tertiary beds. There is a circumstance of unusual interest to be observed in the manner in which the animal increases the size of its shell, and which shows most admirably the regularity and beauty of the laws of Nature, and directs the mind to the contemplation of the wisdom and power of the CREATOR, who alone could teach these little ani- mals how to construct an habitation so perfectly adapted to their circumstances and situation: It will be observed that each periodical increase of these shells consists of a piece which surrounds about a third part or less of the lower portion of the last volution already formed, which portion is always terminated by a varix, which is more or less muricated and even spinose; it it obvious that these murications or spines must be in the way of the future increase of the shells, unless they could be removed from that part which it is intended to cover, the animal there- fore is furnished with the means, probably by a solvent. liquor, of eating away the lower part of these spines, so that they become detached and fall off by the time that he is ready to furm his new inner lip upon the space which they occupy, thus forming a comparatively smocth and even surface on which it is to spread the testaceous matter of which the addition to his building is composed. In our plates we have given figures of some of the species which show the greatest diversity of character. Fig. 1 Murex Haustellum. tenuispinosus. 3 Scorpio. 4 cervicornis. 5 phyllopterus. 6 ———— melanamathos. ——S 4 * i Oa ‘i ad [oe Sa i Og fo had abe o recent wm Ve EEA ih it Ta ay At ACTER» ORS eS Rae) Ni nips a i a oO Ae : ‘ Phi te Peg sae | saul i i ati | : nt i Wie’ fess AE f es f i ‘ ay may 4s = TRITON. — TESTA turbinata, spiralis, apertura quadrato- subrotunda ; labio externo acuto, emargina- tione profunda superné, prope suturam posita. ae ee eee Or the genera distinguished by amore or less deep fissure or notch in the upper part of the outer lip, the Pleoroto- maria of De France (including, in our opinion, the Scissu- rella of D’Orbigny) has no canal, consequently it appears, as far as a judgment can be formed from the shell alone to belong to the family of the Turbinide or Trochide. This Genus, if we except some very minute recent species to which D’Orbigny has given the generic appellation of Scissurella, is only found in a fossil state. We are not aware of its general occurrence in other formations than the inferior Oolite, and the Kimmeridge Shale or Oxford Clay; two exceptions may however be mentioned, for casts are found in a Limestone bed in Norway, which is probably contemporaneous with the chalk, but whose characters are much disguised, and some minute species (Scissurellz) are found in the Calcaire grossier. It appears to us indeed probable that it may be also found in other intermediate beds, though we are not aware of the cir- cumstance. We have not been able to ascertain whether this Genus should be arranged with the Turbinide or the Trochide, for the different species which may properly be called Pleurotomaria differ in form very much, some of them having the exact form of Trochi and others resem- bling Turbines. This can only be ascertained upon the discovery of the operculum, if indeed it possess any, which in the Turbinide is thick and testaceous, and in the Trochide thin and horny: though spiral in both. We can only further state with respect to its place in the system, that it appears to us to bear the same relation to Trochus or Turbo, that Pleurotoma does to Fusus or Fasciolaria. 1%G. PLEUROTOMARIA. Shell spiral, turbinated, sometimes quite conical, and having either a nearly square, or somewhat rounded aper- ture, generally however of a rounded squarish form: the outer lip being sharp edged; and having near its upper edge a deep notch or fissure near the suture. The extent of this notch is proportionally much greater than in Pleurotoma. There is no canal; and we feel it to be. important to repeat this circumstance, because some who are but slightly acquainted with the Genus Pleurotoma might else have enquired, wherein it differed from that Genus, both having the notch in the side; although inde- pendently of this notch there is so much difference in general form. 177. MYA. —~ TESTA inzquivalvis, irregularis, adherens ; valva affixa dentibus duobus marginalibus, di- varicatis, ad umbonem disjunctis, foveola trigona intermedia alteram testacez appendicis - extremitatem, cartilagine cornea connexam, -. excipiente; valva libera dentibus duobus in- _ gequalibus, parvis, divaricatis, altera appendicis extremitate foveolz intermediz inserta. Um- bones valve libere interne, alterius externeé, recurvi. Impressiones musculares duz, orbicu- lares, distantes, laterales. /mpressio pallii sinu brevi, lato. Ligamentum tenue, externum. A NEw and very singular Genus of bivalve shells, lately discovered and first described by Mr. S. Stutchbury in the Sth vol. of the Zoological Journal, p. 96. It was found attached to a smooth species of Pectunculus and to Tri- gonia pectinata at Port Jackson, New South Wales; and it has been named Myochama from the circumstance of its connecting in itself some of the characters of the Myurie and Chamacee. In general appearance Myochama bears so near a resemblance to dnomia, that if particular atten- tion be not paid to its internal characters and the mode of its adherence, it might be easily mistaken for that Genus. The two distant lateral muscular impressions, and the absence of the shelly appendage by which Anomia is attached, easily distinguish it. We have said that Myo- chama combines in itself some of the characters of the Myarie and the Chamacee; those which it has in common with the Chamacee are its muscular impressions, and its being attached by the outside of one valve; while it has in common with some of the Myarie an internal shelly ap- pendage in the hinge: from Lamarck’s Genus Anatina it is distinguished by its being an irregular and adherent shell. 198. ey s et ca * MYOCHAMA. Shell inequivalve, irregular, adhering by the external surface of one valve; this attached.valve has two unequal diverging marginal teeth at the hinge, which are separated at the umbo by the triangular pit in which one end of the testaceous appendage above-mentioned is inserted, and connected by a horny cartilage: the free valve, which is larger than the other and very convex, has two small un- equal, diverging teeth close under the umbo, in which by means of a cartilage is inserted the other end of the tes- taceous appendage. The umbo of the free valve is curved inwards, that of the attached valve outwards. There are two muscular impressions in each valve, which are nearly orbicular, distant and lateral. The muscular impression of the mantle has a short broad sinus. Only one species of this remarkable Genus has yet been found, it has distinct radiating, and rather prominent dichotomous ribs or grooves passing from the beak towards the margins ; these appear to be characteristic; but when attached to Trigonia these natural ribs are crossed by ‘others, caused by the granose ribs of the Trigonia, their position and strength depending upon the situation it occupies. This species has been named Myochama ano- mioides by Mr. S. Stutchbury; it has a thin pellucid epidermis. CLEIDOTHAIRUS.* =< Boe Stutchbury in Zoological Journal, Vol. V., p. 97. Camostrée, de Roissy. TESTA inequivalvis, adherens; dente cardinali -conico, in valva libera, in fossulam alterius val- vee inserto; appendice testaced, elongata, re- curva, cartilagine convex, et in cicatricem profundam infra utrumque umbonem inserta. Impressiones musculares, in utraque valva duz, laterales, antica prelonga, postica suborbicu- laris. Impressio pallii integra. Ligamentum internum. Av first sight this remarkable shell has generally been taken for a Chama,t which it resembles so exactly, that after having ourselves become acquainted with its promi- nent distinguishing character, we feel that we cannot suf- ficiently praise Mr. de Roissy, who has shown so high a degree of critical acumen as to have separated it from Chama, without knowing of the singular circumstance of its having an internal cardinal shelly appendage. ‘This is another Genus which has been fully made known by Mr. S. Stutchbury, who received some specimens in their com- plete state from Port Jackson, in the commencement of 1830. He has named it Cleidotherus, from the remarka- ble circumstance of its internal hinge cartilage, having an * So named by Mr. S. Stutchbury “ from the Clavicle in the hinge.” + Of course we mean here to speak of the Lamarckian Genus Chama: it is to be regretted, that however great the merit of that distinguished naturalist has been in distinguishing the real characters of shells, his system is not adopted so generally as it deserves to be, 197 CLEIDOTHARUS. elongated testaceous appendage, in form resembling the human clavicle; as far as this character goes, connecting the Chamacee with the Myarize of Lamarck. Shell bivalve, somewhat pearly, inequivalve, involute, attached by the outside of the larger valve. Hinge with a small conical pointed tooth in the free valve, fitting into a corresponding pit in the attached valve. A testaceous, rather elongated, curved appendage,* connected by car- tilage, is inserted into a deep cicatrix within each umbo. Muscular impressions two in each valve, lateral, the ante- rior ligulate, the posterior suborbicular. Muscular im- pression of the mantle entire. Ligament external. The only species of this Genus at present known was found attached to sandstone rocks at the entrance to Port. Jackson, by T. Young, Esq., R.N. Some imperfect speci- mens had been sent to England many years ago, probably from the same spot, by Mr. A.Humphrey. Some of these have a brownish red colour, whereas those of Mr. Young were of a dull livid colour. The imperfection of these specimens consisted in their having lost the internal ap- pendage. All the specimens have adhered by the anterior side of the large and deeper valve. * Called by Mr. S. Stutchbury a “ clavicle.”” We do not approve of this application of the term, because, though there is some analogy both in the form and use between this appendage and the human clavicle, they are not cor- responding parts of the animal frame. 200. CYPRINA. Lam. — TESTA equivalvis, inequilateralis, oblique cor- data; umbonibus oblique curvis; dentibus tribus in utraque valva eardinalibus,’ basi approximatis, superne subdivaricatis; dente laterali a cardine remoto, ee te ine Impressiones musculares in utraque valva duce, lateraies, dis- tantes. Impressio muscularis pailii integra. Ligamentum externum, partim in sinu marginali postico, immersum. Epidermis cornea, crassa, olivacea. A Genus of bivalves separated by Lamark from the Lin- nean Venus, and closely resembling many species of that genus in general appearance and form. Lamarck seems to think it scarcely sufficiently distinguished as a genus, we are of opinion, on the contrary, that its characters are well marked. Seven fossil species and one recent are described by him, but we possess three recent species. British Naturalists will be surprised when we assert, from an intimate acquaintance with the Linnean Venus Isan- dica from the coast of Iceland, that our coimmon species generally known by that appellation is perfectly distinct, and must henceforward be distinguished by another name. All the recent Cyprine belong to the Northern hemis- phere, at least as far as we know, for we have never seen or heard of any having been brought from the Southern; they seem to be peculiar to the cold, icy climates of Newfoundland and Iceland: one species alone occurs onthe coast of Britain and the other shores of northern CYPRINA. Europe. The fossil species are only found in the tertiary bed, contemporaneous with the London Clay and Calcaire grossier. t Shell equivalve, inequilateral, obliquely cordate, umbones obliquely curved anteriorly, with three cardi- nal teeth in each valve, approximated at their bases, but somewhat diverging at their upper parts; and a posterior lateral tooth at a distance from the hinge teeth. Two lateral, distant muscular impressions in each valve. Muscular impression of the mantle entire. Ligament external, partly buried in a deep, marginal, posterior, dorsal sinus. Epidermis horny, thick, rough, and of a dark olive colour in full grown individuals, though in young specimens it is frequently very thin and pale. In several characters the Cyprine approach Lamarck’s Conche fluviatiles, a circumstance which he has observed, and it is remarkable that the two species peculiar to Iceland and Newfoundland are generally eroded at and near the umbones; it must however be stated that this peculiarity appears to be common to such shells as belong to very northern, frozen regions, and to such as are found in fresh water and at the mouths of rivers. Ab}. SOLEN. =< oS" TESTA zquivalvis, elongata, subcylindrica, valdé inequilateralis, utradque extremitate hians, — antica brevissima, truncata vel subtruncata, interdum rotundata. Cardo dentibus varliis, plerumque acutis, recurvis; interdum dente laterali, elongato, uncinato. Impressiones mus- culares distantes, antica ligulata, sub vel post umbonem posita, postica irregularis, subovalis; impressio muscularis pallii rectiuscula, lon- gissima, postice bifurcata. In endeavouring to draw up a definition of this Genus we have experienced much difficulty, on account of the very great diversity of character exhibited by the shells which have, by common consent, been hitherto united together as Solenes. In No. XXV. of this work under the article Sanguinolaria it will be seen that we have not hesitated to separate from it several which had hitherto been associated with it. We now think that all those whose anterior muscular impression is placed before the hinge teeth, might without impropriety be detached from it: some of these would go to increase the Genus Psammobia, others form De'Blainville’s Genus Solecurtus, and these inwhich may be observed an incrassated internal rib passing from the um- bones toward the inferior edge, may form a well marked and distinct Genus. Such a separation will much facilitate the task of the learner in arriving at a knowledge of the natural genera, and it will not be attended with any real inconvenience, because it is very evident that Lamarck’s * Solenacées’’ must be brought close to his “ Nymphacées Solenaires’ in the natural system. Adopting this view of the subject, we include in the Genus Solen only those which are generally termed Razor Shells, whose anterior side is very short, and whese anterior muscular impression is placed immediately under or behind the beaks. or ata _* ens SOLEN. Another circumstance which induces us the more readily to adopt this view, is, that the teeth in these, which may be not improperly termed typical species, are so variable that no dependance can be placed on them for generic characters, almost every species being different. It is remarkable that typical species of this genus are found in all parts of the world, and that the resemblance between those which inhabit the shores of Europe, South America, and Australia, is so great that it is difficult to point out good distinguishing characters. Several species are com- mon on the coasts of Britain, of these the Siliqua grows to the length of more than ten inches in the neighbourhood of Belfast. The animal is remarkable for an enormous muscular foot which probably aids it in burrowing in the sand, which it frequently does to the depth of two feet in a perpendicular direction, and it seems to take its station habitually near the upper extremity of its hole, and upon the slightest disturbance it retreats with amazing rapidity to the lower end. Very rarely found in a fossil state in the Calcaire grossier, and in the London clay. | CYTHEREA. —<_ Lam. Se TESTA bivalvis, equivalvis, plerumque plus mi- -nusve inequilateralis; vel obtuse trigona, vel ovalis, vel lenticularis ; levis vel concentrice, vel radiatim striata; dentibus utriusque valve cardinalibus tribus vel plurimis, divergentibus ; laterali unico, antico, plus minusve approxi- mato. Tuk Linnean Genus Venus consisted of an immense assemblage of shells remarkably different in their charac- ters, and in the habits of the animals by which they have been formed. That the Cytherea should have been asso- ciated with the typical Veneres of Lamarck is not surpriz- ing, because their general appearance is much alike, but the decided separation of Lucina, Corhis, Megadesma,* and Cyrena seems to be fully warranted by the great dif- ferences in their general characters. We apprehend that the time is not far distant when the establishment of seve- ral well-marked groups of smaller extent, will, under new generic appellations, be thought desirable. Taking Cythe- rea lusoria of Lamarck as typical, and associating with it such other species as accord well with that in general cha- racters, we shall still find that several very different forms have been associated together, even in the Genus Cytherea as it stands in Lamarck. We feel ubliged to state that, in our opinion the Veneres and Cytherez require a most careful revision ; and that all the species should be arranged * Galathea, Lam. Ad. CYTHEREA. into groups according to their peculiarities, if we would arrive at any thing like precision in describing the charac- ters by which each Genus is to be distinguished ; it would perhaps be found necessary to constitute and characterize several new genera; but this, we think, would be a decided advantage to the science, particular ly when the great number of species, and the great diversity of character among the species that are now arr anged together under those two generic appellations are taken into the account. In order to convey a tolerably accurate notion of Cytherea as it now stands, we shall endeavour to point out the va- rious types of form of which it is composed. First, The typical species, C. lusoria, petechialis, and others, are smooth on the outside, and covered with a thin horny epidermis; there are three diverging hinge teeth in each valve, and a lateral anterior tooth under the lunule, which is elongated, and but indistinctly marked: there is also a small rounded sinus in the muscular impression of the mantle. Their general form is obtusely triangular, the anterior side being rather shorter, and the beak distinctly inclining forwards. The second group of which Cytherea consists, and of which we believe C. Corbis, Lam., is one, has four or five diverging hinge teeth ; a more lengthened, almost lamellar anterior lateral tooth; alarger rounded sinus in the mus- cular impression of the mantle; a lengthened and still in- distinctly marked lunule, a smooth outside, and, in such species as we have been able to examine, a thin velvety epidermis. ‘These are more distinctly triangular, and the beak less inclined forwards. A third group, consisting of C. Chione, Erycina, and others, which are of a nearly regular oval form, having the anterior side much shorter than the posterior: they are smooth on the outside, have a thin horny epidermis, and some of them are longitudinally grooved: they have three diverging cardinal teeth in each valve, anda closely approximated, short, blunt lateral tooth. The sinus in the muscular impression of the mantle is very large, and ge- nerally pointed at its anterior end. The fourth group are nearly lenticular in general form and concentrically grooved on the outside; the sinus in the muscular impression of the mantle is large, oblique, and straight sided ; there are three hinge teeth in each CYTHEREA. valve, and the lateral tooth is generally very small, and closely approximated. One other important group remains to be distinguished ; which leads directly to the typical group of Lamarckian Veneres, and apparently differing from them only in hav- ing a distinct blunt lateral tooth, and in having no sinus to the muscular impression of the mantle. Those La- marckian Cytherez which have the muscular impression of the mantle thus entire, are mostly smooth on the out- side; some of them, however, are concentrically striated, and others have diverging strie and ribs; their umbones are mostly inclined forwards. In these the lunule is more distinctly marked than in most others. C. pectinata, gib- bia, castrensis, scripta, ornata, and other well-known spe- cies beiong to this group. Other groups, distinguished by less prominent charac- ters, and of smaller extent, occur; one of these it may be proper to particularize; it consists of only three or four species, which have been retained among the Donaces by Lamarck, namely, C. meroe and its cognate species; these are remarkable for their nearly regular oblong form, their central umbones, and a deep sulcus formed between the valves immediately behind the umbones: they have scarcely any circumstance in common with the Donaces. We have drawn up the following character of this Genus in such a manner as to admit all the groups mentioned above; much greater precision would of course be neces- sary, were it thought prudent to establish so many different genera. Shell bivalve, equivalve, generally more or less inequi- lateral, obtusely triangular, ovate or lenticular, smooth or variously striated; with three or more diverging hinge teeth, and one anterior lateral tooth in each valve; the lateral tooth more or less approximated to the hinge teeth. Cytherea is nearly related to Venus and Cyprina, differing however from both in having a lateral tooth; itappears to pass into Venus by those species which are nearly lenticu- lar in form, and whose lateral teoth is brought very close to the hinge teeth, for we find in some of Lamarck’s typi- cal Veneres a small vestige of an approximated lateral tooth. The form of the muscular impressions will distin- guish the Cytherez from the Lucine. The fossil species of this extensive Genus belong prinei- 4 03. CYTHEREA. pally to the tertiary formations, being not unfrequent in the Calcaire grossier and the London Clay; they occur also in the green sand, and in some of the secondary beds. Many of the recent species are very beautiful, and natu- rally highly polished, and some are remarkable for pointed spinous processes on the outside (e. g. C. Dione, Lam., Venus Dione, Linn.) They are found in the seas of all coun- tries, but particularly in the East and West Indies: in Japan the valves of C. lusoria are gaily painted and gilt on the inside, and they are then used for games of chance or skill, as our playing cards. - ANATINA. —<—o TESTA transversa, libera, inzequilateralis, ple- rumque inzquivalvis; utroque latere hiante: plerumque processu parvo, cochleariformi, ligamentifero in utraque valva et appendice testacea, curva, parva, interdum minima, ante processus ligamento connexa. APPARENTLY related to Mya in the habits of the animal, as well as in the general characters of the shell, but well distinguished from it, by its having a moveable testaceous appendage connected with the ligament immediately before the hinge teeth. It is observable that Lamarck, who established the Genus, should not have mentioned this singular appendage, of course founding its claim to generic distinction upon the difference of form and posi- tion of the ligamentiferous processes; this little appendage is, however, in some species so small, and in general so deciduous, that it is not surprizing Lamarck should not have noticed it—the specimens which he had the oppor- tunity of examining having probably lost it. We must not here omit to notice that Lamarck’s Amphidesma corbuloides belongs to this Genus: it is the Mya norvegica of authors, and the Lyonsia striata of Turton. There are so many differences in the characters peculiar to each species, which may, without impropriety be united under the generic appellation of Anatina of Lamarck, that it is difficult to find any set of characters in which they generically agree; in some species the valves are both equal, in others they are unequal; in some there is a distinct spoon-shaped process to which the ligament is attached, in others this process is much less evident, while there are several in which it does not exist at all; in some the accessory, internal, testaceous, appendage (the 204. ANATINA. presence of which, in a free bivalve, constitutes the essen- tial character of the genus) is very small and of a curved semilunar shape; in others it is proportionately large, though of the same shape; sometimes again it is flat and placed without the intervention of any cardinal processes against the internal ligament. Notwithstanding this remarkable diversity, we cannot consent to separate any of these from the rest, because we are convinced, that if any separation were allowed, it would be necessary to raise nearly every known species to the rank of a genus. Wherefore, as far as regards those bivalves which have an internal testaceous appendage, we are Satisfied with separating from Anatina only the Myochama and the Clei- dotherus, both of which differ from it in being fixed. The nating may therefore be described as free, transverse, inequilateral bivalves, generally with unequal valves; sometimes gaping, sometimes nearly closed at both ends, geverally having a small spoon-shaped inter- nal process, to which the ligament is attached, in each valve ; in connection with which there is a small, variously shaped, testaceous, internal appendage also attached to the | ligament, and apparently serving to strengthen the con- neetion between the two valves. Fossil in the tertiary beds only. All the species are marine. NAUTILUS. oe TESTA univalvis, libera, suborbicularis, conea- merata, convoluta, anfractibus contiguis, septis transversis, extus concavis, siphunculo per- | forato, marginibus integris; apertura amplis- sima. Attuouen, by common consent, this has been called Nau- tilus, even among scientific authors, it is not the Nautilus of Pliny*, nor does it seem to be better entitled to the ap- pellation, notwithstanding its cephalopodous animal pro- bably possesses the power of raising it to the surface and swimming about thereon while living, and notwithstand- ing it appears that the shell, when the animal is dead, must necessarily swim, in consequence of its peculiar construc- tion, rendering it specifically lighter than the water, until the chambers becoming filled with water after all traces of the animal are gone, it would as surely sink to the bottom. Our reason for supposing it undeserving of the ‘name it bears, is that it could not swim in such a position as would make it bear any resemblance to a sailing vessel, and it is not prebable that its animal, which is carnivo- rous, and whose prey must be constantly in the water, should have either the means or the disposition to place its shell in such a position: and even if we were to sup- pose that the animal had such means, whichis indeed most * The commonly received fictions (first broached by Pliny) which have sometimes been so elegantly embodied, do not belong to this, but are intended to apply to the Argonauta or Paper Sailor. 245. NAUTILUS. improbable, because it would require the exertion of such a kind of instinct and muscular action as must be entirely useless to it, it would certainly be very little, if at all dis- posed, to leave the pursuit of its prey in order to take a pleasant sail on the surface of the ocean. What we have here stated is on the supposition that its animal is cephalopodous, (and we think there is much reason for adopting that opinion), and it is well known that the cephalopoda are exceedingly voracious; we cannot there- fore suppose that its time would be otherwise occupied than in pursuing the bent of its natural dispositions. If any of our readers, desirous of ascertaining the probabi- lity of this animal sailing about on the surface of the ocean, will place one of the shells in a vessel of water sufficiently deep, it will be found to swim exactly in the position in which we have drawn it in our plate, in which position if the animal were in it and partly surrounding it, as it most probably does, its head and body would be entirely covered by the water, and no part of the edge of the shell could be visible; thus supposing the shell to resemble a boat or sailing vessel, it could naturally only swim with its stern upwards; and to keep its gunnel above water it would require ballast, and the nicest possible balancing: in fact it appears to us that neither the Nau- tilus nor the Argonaut could possibly swim about with their shells so placed as to resemble a galley or skiff. Of recent Nautili three or four species at most are known, which we believe to be all inhabitants of the Pa- cific and Australian, possibly extending also to the Indian ocean. ‘The fossil species, which are more numerous, are found not only in the tertiary beds, as the London clay and the Calcaire grossier, but also in several of the beds belonging to the secondary class, particularly among the Oolites, and as low as the Mountain Limestone. Shell univalve, not attached, suborbicular, convolute, with contiguous volutions, in which respect it differs essen- tially from Spirula, whose volutions are separated; chambers numerous, the septa transverse, concave out- wardly, perforated by a siphunculus, and having their margins entire: aperture very large. Lamarck says in NAUTILUS. his character of this Genus, that the last volution covers the former ones; but it may be observed that this is really the case in one species alone, the Nautilus Pompilius, whereas in the N. umbilicatus and N. scrobiculatus, the former volutions are partly exposed: this should not there- fore enter into the generic character. We find it impossible by words to convey a descrip- tion of the form of this remarkable shell, we are, how- ever the less solicitous about it, as our account of it is accompanied by a representation which will convey to those who are not yet acquainted with it a perfect idea of its form and general appearance. Lamarck states,* that the Nautilus Pompilius is found in a fossil state at Courtagnon, Grignon, Chaumont, in the environs of Dax, &c. and adds, “ C’est veritable- ment la méme éspéce que celle qui vit actuellement dans les mers des Indes.”’ This assertion is not true, at least with reference to the species found at Dax; the conclu- sion he draws from it, supposing it to be a fact, is there- fore untenable. * Hist. Nat. des Anim. sans vert. VII. 634. AVG. HDHD wnibvilegs taal asd ded anemia are ef eit tnd hovieado.od.ganatt aviliqaod enliins”. odd yoaoke: pot ‘od autnlaoidonga . UA bas amtactth ~! stodt toa bluoda wid’ : boadyes yf Bi Sy PROTO MTR 9 PRD “giao, & eon poo OF ehrawogd sidieanen ROHL ie ow: lHodd afd radaaniat nbd at ti. to avenen ‘He aw ab neds | hadi eae os a werd ketisteosigie ee poy eee as leno? al wlliagan’ aww, ode dam (4. diporetgcmrt: >} Mot seoagagsrod ie. ~gliinihroy, saa J ebbe bers ami » copie: Hiab daomolinginn div inp ailsy td one tanelis , ory tort: ee ee ay ata y tomas “0 is “eign? #) Ror. ARGONAUTA. ~ e—- TESTA compresso-subconica, basi affixa; valvis quatuor, inzequalibus, duabus majoribus, dua- bus minoribus, lateraliter intertextis composita; apertura trapeziformi, operculo bipartito clausa. Valvis operculi, aitera irregulariter tetragona, altera subtrigona. Distinct from Creusia, although the external shellin both consists of four pieces. In this the four pieces are irregu- larly unequal, and the operculum, moreover, consists of only two pieces which are also unequal. This is the Lepas striata of Pennant, L. Verruca of Gmel., and it not unaptly resembles a small warty excres- cence adhering to the outside of other shells, &c. Two recent species only have occurred, one of which is common on our own coasts, the other has only lately been brought from the coast of South America adhering to Mytilus magellanicus, and to other shells. Shell of a very flattened conical form, irregular, adhering by the ‘base, composed of four unequal valves, two larger and two smaller, laterally joined together by the interlocking of their dentated edges; none of these valves are exactly alike; the aperture is rather laterally placed, trapeziform, and entirely closed by a bipartite operculum, one of whose pieces is irregularly quadrate, and the other nearly triangular. Of the two species we have selected for our illustra- tion that which has not yet been described, it differs from the common European species, of which we have also given a magnified representation, in the outside of the valves being smooth, whereas in Cl. Verruca they are striated: we callit Cl. levigata: the two species may be dis- tinguished by the following diagnosis. 1. Cl. Verruca, testa valvis externé rugosis. Syn, Lepas Verruca, Gmel. et nonnull. Lepas striata, Pennt, et nonnull. Balanus intertextus, Pult. Creusia, Lam. Obs. Evidently placed by Lamarck as a species of Creusia. 2. Cl, levigata, testa valvis externé levigatis. LOS. fi. | 2 i) . ah ae ft ‘ ‘ b ran . x ¢ ii , wal urs Ae BR f aad eal : a ee eas Me at) von Enophicadiibiguy c \ h olen el elation ~ eee eae ene p EN, CEU PES hee E Sey a ‘3 ware we F ha} es 9 ; re ‘ y ite oo ree). eae iy ee acl ea SET ONY hed fs bye to8 S12 PRES Tee Te Hier nee Bai | eae Bsc sts i De TY shee ress aaa . - - ; ee 5 ee ; : py ia bons Vothhatuoteds neato qubiepe | 3 oe me ie ABs i ig) Stat Sil bys. Be vot a. i. vf We bE! i ary ve : M ‘ phhy: inks, . i BN : , wr hs See bt be og ? I rawuts yiotiies ; ~ ea % ings! $9 teyaribabs ¥ oat s -e : f AB ih oye earn err x t . a ena Es tee ie iy Five teed stets ‘ ie Boe Maji@ost 40 ted) LOUD anged ae i is ‘ Bi wihlje ogo Py: dat 5 $ ye Bea ih? yh iinet My wiltes ; . H wa + 4 ' i i la ys imate ee res } ae | Eee! ; ; k | o:eR Aveo ad baoale: yes S Bue eagive SHI ADRIVIRY htaod. oveigisanh * ae F ? ange ee 3 4 a b. on ‘ (a \ 2 . ; ¥ A‘ ey x i 5 : i: m w y + ; CARDIUM. —_—— Linn. <= e TESTA equivalvis, subequilateralis, interdum posticé hians, costis ab umbone divergentibus ut plurimum ornata; margine interna dentata seu crenulata: dentibus cardinalibus in utraque valva duobus, approximatis, obliquis, crucia- tim insertis; lateralibus duobus: remotis, im- pressionibus muscularibus duabus, lateralibus, distantibus; impressionibus muscularibus pallii integris. Ligamentum externum., at cee Se Tae Linnean Genus Cardium is so natural an assemblage of related species, that it remains nearly, if not altogether in the same state as it was left by that great naturalist ; neither Bruguiére nor Lamarck having thought it desir able to separate any of the species as forming a ‘distinct genus. We have thought one or two fossil species which Lamarck had united to Cardium, more properly associated with Hippopus, our reasons for which we have already explained in our account of the latter Genus. We are the more surprized at this Genus having always remained entire, because the species thus combined vary in general form as much, if not more, than those of any other Linnean Genus, some being nearly globular, others compressed and longitudinal, others much shorter from front to back than they are deep or wide: we beg, however, in saying thus much, to express our entire approbation of this alliance, which appears to us, as far as the shells alone Lee CARDIUM. are concerned, to be perfectly natural; and we have no doubt, that if the animals of all these species were known, they would be found fully to evidence the propriety of it.* That a Genus of so great importance should be passed over with so few observations may perhaps appear strange, but it really presents itself to our view with so few encumbrances, that we have nothing more to say or do than to describe the characters peculiar to the Genus and give a somewhat detailed view of the principal external forms included in it, and, stating some particulars relating to the characters and habits of its animal, conclude with such information as we have relating to its fossil species. The species of the Genus Cardium must be described as equivalve, although there is always a slight difference in the form of the two valves: they are nearly equilateral, and more or less gaping posteriorly: the outer surface of some few of the species is smooth and shining, but for the most part they have more cr less strongly marked ribs, radiating from the umbones to the margins: inner margins, except close to the hinge surrounded by larger or smali teeth or crenulations according to the size of the radiating ribs, those species which have no ribs, having neverthe- less very fine teeth round the inner margin. Cardinal teeth in each valve two, placed very near together, oblique, and locking into each other cross-wise: there are also two remote, lateral, teeth in each valve:+ muscular impressions two in each valve, lateral, distant: muscular impression of the mantle entire. Ligament external. We have stated that the Cardia vary much in general form; thus, some species are nearly globular, such for instance as the C. tuberculare; some are deeper than they are long or wide, suchas C. biradiatum: some are longer from front to back than in any other direction, one of these has been called C. scleniforme; others have a pro- minent nearly central ridge commencing at the umbones * It will be observed by some that we here write upon purely concholo- gical principles. Cardium must be regarded asa natural Genus, even by those who cannot consent to the formation of a natural system, founded upon. the combined consideration of theanimal inhabitants in connexion with the shells, which we are nevertheless persuaded can alone be the foundation of the natu ral system. 7, + One species is remarkable for being almost destitute of teeth, it is the Cardium edentulum, Lam. CARDIUM. and passing to the ventral margin, some of these are much shorter from front to back, and much wider from side to side than in other directions; the C. Cuardissa isa remarkable example of this form. The form of C. hiber- -nicum* is very remarkable, its anterior extremity being very wide and obtuse, and its posterior end being narrow and produced into the form of a lengthened beak-like process. Little is known at present of the natural affinities of the Genus Cardium; Trigonia, and Isocardia appear to be most nearly related to it: a strong muscular foot, which enables them to move with considerable rapidity seems to be one of the most prominent characters: in the Trigonia this is so strong, that some specimens of the T. pectinata which Mr. S. Stutchbury laid upon the seat of a boat preparatory to putting them in spirits, leaped over the gunwale and rejoined their old companions. The fossil species of Cardium occur in nearly all the fossiliferous beds from the Mountain Limestone upwards. In the Mountain Limestone occurred the C. hibernicum, of which we have already mentioned some peculiarities. But the fossil species are much more numerous in the newer formations, as in the green sand, London clay and crag in England, and in their contemporaneous beds in other countries. # Weare informed by the Rev. J. Bulwer that the fossil which has hitherto been called Cardium hibernicum has no claim to a place in this Genus. At0, Weve ‘ms f. 4 sabe y fi 1 I ’ % i a x i d »! ; ‘ et ’ ’ 35 i HS s 9 Ree ew eR. a7 E ol abba End fa 6 to 7% hy “wis Wy : 4650 Ne acti ; FH y isd: af final adi teil) yowkul Y : z P * mar ey rad! r - sy, : ., Si * rae Mi ely Bis § ‘ Z Shan l ' - Cart . ‘ AMMONITES. 4 —~ Ammonites and Orbulites, Lam. Anim. sans vert. Ammonoceras, ejusd. wnattPy ly flimen-» TESTA discoidea, cenvoluta, polythalamia, an- fractibus contiguis, marginibus septorum loba- - tis et sinuosis, siphone dorsali. Amone the various fossil shells which abound in the secondary beds, and which are not known in a recent state, one of the most remarkable and numerous is the Genus Ammonites, commonly called Cornu Ammonis from its resemblance to the convoluted horn generally repre- sented on the head of Jupiter Ammon in Mythological History. _Snake-stone is also a name that is topically applied to these fossils, and their resemblance to a coiled snake is surreptitiously aided by an artificially formed head. This Geuus, which consists of discoid, convoluted, chambered shells with contiguous volutions, the margins of whose septa are lobated and sinuous, and whose siphun- culus is dorsal, is very nearly related to Nautilus, differing from it principally in the position of the siphunculus, and in the circumstance of the lobated and sinuous edges of the Septa. We unite Lamarck’s Orbulites and his 4mmo- noceras with Ammonites, because we cannot discover any sufficient distinguishing character. The circumstance in which they differ, and which has caused Lamarck to separate them, is, that in the Orbulites the last volutions covers all the former, while in Ammonites all the volutions are apparent; this, however, is not a sufficient character, _ because there are connecting species, and if it were admitted, it would be necessary to separate the only three known recent species of Nautilus into two genera: the existence of an umbilicus can never be regarded as a generic distinction, inasmuch as in some instances it is I}. AMMONITKS. not even specific. .dmmonoceras is only an accidentally worn portion of an Ammonite. Nothing can of course be known concerning the animal which forms the Ammonite, nor of its habits ; it appears to us a singular circumstance that so many species should abound in all the secondary and in some of the tertiary beds, and yet that no recent species Should be known. Lamarck supposes it probable that they may live in the great depths of the sea, and we are much inclined to adopt such a supposition (and to hope that the discovery of recent species will soon reward the exertions of some enterprizing Naturalists,) because we are at a loss to imagine the possibility of their being entirely lost. We know, concerning the Terebratula, the only other Genus which abounds in all the secondary beds, and which is there associated with the Ammonites, that some of its species are found as abundantly in a living as in a fossil state: and we know no reason that the Ammo- nites should not be found, since recent Terebratule and Trigonie which a few years ago were known only in a fossil state, are now to be seen in many collections. We have represented three specimens, one to show an Ammonites, another an Orbulites according to Lamarck, and the third to show the sinuous and lobated edges of the septa. ~BACULITES. —V Oo TESTA recta, gradatim crescens, concamerata, marginibus septorum lobatis, sinuosissimis, si- phone dorsali: ultimo articulo elongato. aD A Genus which is only known in a fossil state, it was first discovered by Faujas de St. Fond in the Limestone of Maestricht, where, however, it does not appear to be so abundant as in a similar Limestone in the the neighbour- hood of Valognes, in Normandy, from which latter place we have occasionally received some very fine specimens by the favour of our kind friend C. D. DeGerville. This Limestone appears to be of a peculiar sort, characterized by the Baculites and Hamites contained in it; all its fossils are casts, and if we were permitted to form our judg- ment of its age from these casts, we should say it appears to us to be nearly contemporaneous with the Calcaire grossier, for it contains casts of several of the shells that are most characteristic of that bed. This is a very remarkable Genus, nearly related to Ammonites, and differing from it in being straight; it bears the same relation to Orthoceratites that Ammonites does to Nautilus, having its chambers lobated and very sinuous at their edges. Being only known in a fossil state, we are not of course at all acquainted with its animal, yet we venture to give an opinion that it must have been almost, if not entirely an internal shell. It is probable that there are many species of this Genus, but as we only know the casts of the insides, we cannot indicate the specific Ale. * iq * "~ BACULITES. differences, which consist, most probably, in the external characters. It should appear, from the circumstance of their increasing in thickness so very gradually, that they may attain to a considerable length; the most complete we have seen have been about ten inches long: and the last chamber is generally several inches in length. Faujas and Lamarck appear to have confounded the Hamites with the Baculites. HAMITES. —~<=oe TESTA cylindrica, vel subcylindrica, elongata, attenuata, hamiformis, concamerata, marginibus septorum sinuosis, siphone dorsali. AnotHer remarkable Genus of shells belonging as is supposed to the cephalopodous Mollusca, and related in some respects to Ammonites. It was proposed by Parkin- son to include some singular polythalamous fossils found in the Chalk Marle, near Folkstone, but it has since become more important, by the addition of some larger species from other localities and various beds. The fine specimen we have represented is from the Baculite Limestone at Fresville in the vicinity of Valognes, in Normandy. The Hamites differ from the Ammonites in not forming a spiral discoid, and from Baculite in being bent, and form- ing two nearly parallel limbs, not quite contiguous to each other. Our account of this Genus must necessarily be incomplete, for neither of the terminations have ever been seen: as far as we know it may be distinguished as— a cylindrical or nearly cylindrical shell, which is elon- gated, attenuated, and bent into the form of ahook, (whence its name,) its chambers are numerous, and the margins of the dissepiments sinuous, its siphunculus is dorsal. The Hamites occur in the Chalk Marle, and in the Chalk, particularly in Kent and Sussex. 213, a he \ rg a ae ee oe egnols ~asoinballyador Jor a / . eptiahpieni cherries aes, aires dle. vole ondsigie Pie a ee gulaaolod siliade bo pepgiadd . , ft botatet bas woenilal enendqel % ws wie 4 ri hasecnate & BA 7] Pas He Fe steal axons abatiry tog alebat aie eee tied motel sacl oseties yea a wt slid it ad ba: : du: eneioonackt obtinenGl elt molt a Say thane ut asmoln¥ Yo 9 welnret jon ti avd icaceeaer A, eile ne fob ban aad gaied nf atta a) eporgitnys silsp ton sdentl (et BF seat -ylitaeeeson josie ecnwvet) eis? Yo jaan stove. avail scehinbiores oft te odhine as hadeingatterbh od yet 3 wood ow sole si dpidw Hoda lnstthetlyy ¥ oon) dood ste wl od! vial tasd b: io nates ott bus auotoume oun eiodk Ape ef gulpoaudgia ott encunia od? ni uae - atts iff died ae) ai idan ‘. Soaee * has ten wi ¥ SCHAPHITES. =< 3o a TESTA concamerata, involuta, anfractibus primis minoribus, ultimo dilatato et elongato, demum attenuato et inflexo, septis lobatis et sinuosis. A Fossit Genus established by Parkinson and related to Ammonites, but differing much in its general form in consequence of the remarkable extension and inflexion of its last chamber. It is found, but rarely, in three conti- guous beds, the Chalk, Chalk marl and green Sand: in Sussex, Wiltshire and near Rouen in Normandy. Shell chambered, involute, its first volutions small and increasing very gradually; its last elongated and dilated or expanded, and then diminishing and turned inwardly; the divisions of the chambers lobed and sinuous. It is probably in a great measure, if not wholly internal; of course nothing is known of its animal, though it is supposed to be cephalopodous. £/4¢ * leouaia PSAMMOBIA. —o-e— Cuvier. —<_<+o— TESTA interna, dorsalis, haliotoidea, tenuis, superné convexiuscula, vertice laterali, subter- -minali, inflexo. eee Frrast noticed and described underthe denomination of Bulla Plumula,* by Montagu, who has described the animal as well as the shells, although our continental neighbours have not chosen to give him the credit of having first made known this very remarkable animal. The name applied to the animal by Cuvier, refers to the position of the Branchie, which form a sort of feather-like appendage attached to its right side. It is observable that this name has no reference to the shell, a circumstance which would be much to be regretted, but that the shell is so slender and thin that it is scarcely likely to be met with separate from the animal. The general form of the shell is very much like that of an Haliotis, it is very thin, and is placed on the back of the animal, being entirely internal and hidden by the integuments: it is rather convex on the outer or upper side, with a lateral, nearly terminal, in- flected vertex. Few species of this Genus are known as yet, though it is probable that there are many; two, atleast, are natives of our own coasts, and several others are known as in- habitants of the coasts of the Red Sea; they have lately been described by Ruppell. There are no fossils which can be referred with certainty to this Genus. * See Mont. Test. Brit. 2nd Vignette f. . 1803. For another species which Montagu has called Lamellaria membranacea, see Linn. Trans. Vane Prabies Aa Scne cghe \ \ i aoe My 4 ee is , yy BA 4 a ALG Sis ® ae Hi ; anid 3 aa py f | Oth oh vg Ath A We pies ey . R , : ‘ae bans od a4 int acetal aioe ie ott 4 5 . , of * ; i y ’ .) 1 Ae) jl 4] ' *, ui ‘ ; Pa f 7- x , | | | = ~ rT > ; : | | eine "4 / i | | i é : : | ‘ a Ai) ge u ; * Ps Ye f f | . CYCLOSTOMA. —<—@>oS-—- TESTA turbinata, spira plerumque obtusa, an- fractibus rotundatis; apertura ferée circulari, peritremate superne plus minusve angulato, nonnunquam incrassato et reflexo. Operculo spirali. Tats Genus when first established by Lamarck, consisted, like some of the old Linnean genera, of an assemblage of - land, freshwater and marine shells, differing among one another most materialiy in respect to their essential characters. My readers, who have not attended to the progress of knowledge relating to the Mollusca, will be surprized at being informed, that, taking the form of the aperture alone into consideration, Lamarck at first united together in his Genus Cyclostoma, shells, which he after- wards saw the necessity of separating from it, under the names of Scalaria, Delphinula, Paludina, and Valvata; genera, all agreeing very nearly together in the form of the aperture, though differing essentially, not only in the characters and habits of their animal inhabitants, but also in the structure and peculiarities of the shells themselves. Hence we infer the impossibility of attaining anything approaching to a natural Conchelogical System, for if an arrangemant of shells be made from the consideration of their apparent resemblance to each other, it will be found - that the consideration of their animals will prove such arrangement of the shells to be far from natural; the affinities of the animals will not at all accord with those of the shells alone. We will, however, endeavour to demonstrate, as nearly as possible, the impropriety of the particular combination above-mentioned, and also to describe the peculiarities of each of the genera that have been thus combined, and to show their relations. The present Genus differs from Sealaria, inasmuch as there is never more than one period of growth, conse- LIP CYCLOSTOMA. quently the lip is thickened when full grown only, and there are none of those varices ornamenting the outer surface, which add so much to the beauty of the Scalaria.* The Delphinule (which are nearly related to Trochus and Turbo) are of avery different texture, being perlaceous within, they are moreover of a comparatively thick sub- stance and the lip is not reflected when full grown. The Paludinze and Valvatze which are related to Ampullaria, approach more nearly to Cyclostoma than the Scalaria or fhe Delphinule do, though independently of the great difference in the form of their opercula and their aper- tures; these also may be known from the greater number of Cyclostomata by their not having a reflected lip when full grown. The Cyclostomata have been very properly separated from the Linnean Genus Turbo, and the Genus as thus established has been adopted by Lamarck and subsequent authors ; I have included in it all Jand shells having the following characters. Shell turbinated, thin, mostly with an obtuse apex to the spire, and with rounded whorls: aperture nearly circular, peritreme more or less angular at the upper part, sometimes a little thickened, generally reflected and fringed externally. Operculum horny, in- clining to testaceous in some species, spiral. All the Cyclostomata are land-shells, and most of them are tropical; one or two only are found in Britain, and very few others are European. The animal of one spe- cies alone, the C. elegans, is known in this country, it is ably described by the Rev. M. J. Berkeley, in the Zoolo- gical Journal, vol. IV. p. 278, to which I refer. The Genus appears to be very nearly related to Helicina, though differing materially in the form of the aperture and in the operculum. One species, namely, the C. Turbo, ap- proaches so nearly in form to the Helicina, that, not having seen its operculum, I cannot be quite sure that I have placed it properly in Cyelostoma. The shells of this Genus mostly belong to the southern hemisphere, over which the various species are spread in every direction: the European species are very few and small, while several fine species are found in the East * The Scalarie approach very nearly to the Turritelle. _ CYCLOSTOMA. and West Indies, and in the Islands of the South Seas ; and though we have received a great assemblage of vari- ous shells from North America, we have not a single Cyclostoma among them. Of fossil species there are very few; the C. Mumia, which occurs in some of the upper tertiary beds in the vicinity of Paris, is the only decided fossil species we are acquainted with ; for though Lamarck mentions seven or eight fossil species, it is more than probable that most of them are Valvate. Lamarck has described twenty-six recent species, which are probably true Cyclostomata, for his C. Mumia is, as he afterwards states, is only found in a fossil state, and his C. truncatulum, which he has adopted from Drapar- naud, is not a Cyclostoma. I am acquainted with more than eighty species, but there are several of Lamarck’s which I cannot recognize, namely, C. ambiguum, C. de- cussatum, C. lineolatum, C. mammillare, C. orbella, and C. multilabre. I have represented several species showing as great diversity of form as I know to exist among the shells composing the Genus. One of these is nearly dis-. coid, and shaped very much like a Planorbis, another is nearly cylindrical, one has an undulated fringed margin to the aperture, and another has no reflected margin. Lig me « R vats) mene & be rina at OMe Sires: * face ane poe gh aa! id hi oral 1: a i iabeyreirte De gee eth. fs p "i iF » optieain, bes a ‘ oie ae ae = ¥ et EA ‘ te 1 ae i > and Tae Ns . 7" Hv! i . ia . * vd ' . q Aes i! ~ i ‘yf { i ¢ / ai i} ye ( " - i ~ Ts sity P 2 i 4 SPIRULA. —<— TESTA univalvis, libera, concamerata, convoluta, anfractibus paucis, disjunctis; septis siphunculo _ perforato, marginibus integris. Animal Cephalopodum. DistincuisHED from Nautilus by the separation of the volutions, and from Ammonites by their chambers not being sinuated at the edge. This is a remarkable and elegant little shell, whose animal is undoubtedly a Cephalopod in a great measure covering the shell. It has been described and figured by Peron and Lesueur in the Voyage de Découvertes aux terres Australes, vol. I. p. 45, pl. XXX. £4. a. 4. b. Shell univalve, free, internal, (partly seen through the posterior extremity of the animal,) convoluted, chambered; volutions few in number, separated; the septum or wall dividing each chamber perforated by a little siphon or tube, which passes through the chambers without opening into them; margins of the septa entire. Only one species of this Genus is at present known, which is recent, and inhabits the Atlantic and Indian Oceans. Its animal appears to be pelagic, and when dead, the shells are found in abundance floating on the surface of the water. They are also frequently thrown on the shore. ie 2h K ” Pit ® : ‘ be - ; f ~ oe te j ‘ s) \ y aS tee f ~, 4 ‘ : \ ; a " - ere wmea ot ‘ f a na ’ hive ‘ eh ay ‘ ce ; ‘ ; + mh eye hey ps ~ . Nat i r199 f ’ - p ia ‘ } > v a 4 ! = rere m , ‘ * : ‘ } Fy pte r ek i i ‘ ae 4 . fd A ¥ t Ge Pa i an ¥ a y t + fi i ay 2 y r ‘ 4 ' CARINARIA. Lam. TESTA univalvis, tenuissima, hyalina, coniea, _vertice reflexo, in spiram eonvoluto; lateribus compressis; dorso unicarinato, apertura oblon- ga, integra, latere dorsali acuminato. Animal heteropodum, TuE Glass Nautilus or Carinarza has been long remarked as one of the most singular and beautiful of shells: In our opinion it must be regarded as very nearly related to the Argonaut. So thin and fragile a shell seems scarcely fitted for the place which it occupies about the animal, namely, that of covering and protecting the important viscera, and were it not for our knowledge of the fact that it is external, we should be disposed to think it required a thick and strong covering for its protection against ‘the turbulence of the waves, did we not believe that He who formed it hath made ‘ nought in vain, or not for admirable ends,” and fashioned even this frail vessel with the structure most appropriate to its destined pur- poses. The animal, of which this elegant shell forms an essential part, is itself very remarkable, and may be re- garded as characteristic of a peculiar family; for repre- sentations as well as fora particular description of it by M. Verany of Nice, we refer to the Zoological Journal, vol. V. p. 325. , PVA. CARINARIA. There are two species of this remarkable Genus, one of which has very rarely been brought from Amboyna, the other is not uncommon in the Mediterranean. Shell univalve, nearly equilateral, very thin, trans- parent as glass, and extremely fragile, conical, with a reflected, convoluted vertex, sides compressed, back witha single keel: aperture oblong, entire, its dorsal end acumi- nated. We have given two views of Carinaria Mediterra- nea. ELMINIUS. | ae Leach, in Zool. Journ. —> TESTA eequivalvis, regularis, inzequilateralis, lunula hiante, margine ventrali sinuoso; cardo alterius valve, dentibus duobus posticis, quorum alter brevis, alter elongatus; alterius, tribus, quorum unus brevis, duoelongati. Ligamentwm submarginale, sub-externum, fulecro intra-mar- ginali. Animal bysso tendineo rupibus afixum. Few genera are so perfectly distinct as the present ; sepa- rated from all others by characters peculiar to itself, it can scarcely even be said to be nearly related to any, if indeed we except Hippopus, to which in general form and in its remarkably sinuated edge it is closely allied. This, together with Hippopus, Cardita, Chama and others of very different characters are associated by Linneans under the geveric appellation of Chama, than which association nothing can be less natural. One species of this beautiful Genus is remarkable for the enormous magnitude to which it attains, the T. Gigas ; it is the most gigantic of all shells; we refer to Dillwyn for an account of a pair of the valves of this species, which are used as “‘ Benitiérs’’ in the church of St. Sulpice, at Paris, weighing more than 500 pounds, and Lamarck speaks of even larger. Shell equivalve, regular, inequilateral, generally lon- gitudinal, with a wide opening placed immediately anterior to the umbones, for the passage of a strong tendinous Zig TRIDACNA. byssus by which the animal fixes itself to the rocks. The posterior dorsal margin is nearly straight, and the liga- ment which is elongated, is affixed to its fulcrum just within the margin, so that it is not wholly external, though it is partly on the outside. The teeth, in one valve, are two, one of which is short and placed close to the umbo, the other elongated and near the margin; in the other valve, three, one of them short, and placed near the umbo, the others more lengthened and posterior. The whole of the ventral margin is deeply sinuated. The mus- cular impression may be traced, a little way within, around the whole margin, and it is more expanded toward the center of the ventral margin. The shells of this — Genus are almost always of one colour, most commonly white, sometimes yellow, very seldom orange or rose coloured, but without variegation; their external surface is covered with broad radiating ribs, which are frequently crossed transversely by broad and high. vaulted scales, giving the shells a very handsome appearance. This Genus is only found recent and in tropical climates; we believe the East Indian and Australian Seas alone supply specimens of it. It differs from Hippopus in having a large opening placed just before the umbones. With Chama, Lam. it cannot be confounded, for that is an irregular shell affixed by the outside of one valve. We have represented Tridacna elongata, Lam. GALEOMMA. a av a a Turton. < TESTA tenuis, plerumque ovalis, zquivalvis, equilateralis, margine ventrali hiante; dente _ eardinali in utraque valva unico; impresstonibus muscularibus duabus, subapproximatis, impres- stone musculart pallii interrupta, sinu nullo; ligamento parvo, duplice, parte interna denti eardinali propinqua, parte externa fulero pro- minenti affixo. First discovered by Dr. Turton and described by him in the Zoological Journal. A figure is there given from the only specimen that had then occurred; several have, however, been found since, and we possess four or five species from various localities. Shell thin, generally of an oval shape, equivalve, and equilateral, with the ventral margin widely gaping: there is a single small cardinal tooth in each valve: the muscu- lar impressions are two, they are lateral, though somewhat approximated: the muscular impression of the mantle is interrupted, but there is no sinus: ligainent small, double, one part internal, close to the cardinal tooth, the other part external and fixed to a rather prominent fulcrum. The animal has been found alive; we have, however, so little acquaintance with it that we do not venture to suggest anything about its affinities; we are informed, however, when living it is affixed to stones with the valves spread widely open. Mr. Gray has obligingly favoured us with the follow- ing descriptive observations on this shell and its ani- 230 GALEOMMA. mal, which he has been enabled to make from specimens collected on the coast of Sicily. ‘“ The mantle of the animal is flat and stretched across the gape of the ventral edge of the shell, where it is furnished with a fringe that is attached to the epidermis of the shell, as in Gastrochena, it has, however, only a short linear contracted opening at the posterior part of the gape: the foot is squarish, compressed, its base linear, truncated, of the size of the groove in the mantle. The structure of the mantle and foot of this animal is most like that of Gastrochena, but it differs from that animal in not being provided with an elongated siphon, and the shell which approximates somewhat in form to some of the most gaping Gastrochene is at once distinguished from that genus by the umbones being more central, by the interior being destitute of any siphonal impression and by its having an internal cartilage. The shell is covered with a thin membranaceous epidermis which is easily rubbed off when fresh, and thus the shell is left white, semitransparent and marked with very fine slightly raised radiating striz, the umbones are semiglobose, smooth, with a distinct circumscribed edge, the ligament is ex- ternal, linear, expanded over the outer surface of the rather narrow cardinal facets, with the cartilage placed ina small, short triangular pit immediately under and slightly prominent beneath the umbones; the impres- sions of the adductor muscles are roundish and distinct, the front one has a smaller muscular impression above it, and there are two indistinct impressions extending nearly all along the arch of the cardinal edge.” Galeomma Turtoni. — Mauritianum. Fig. 1. 2. 3. 4, aL TROCHUS. ~~ o TESTA conica, spira plus minusve elata, periphe- ria plerumque angulata, interdum rotundata ; apertura plus minusve transversim depress, subtrapeziformi; columella arcuata, basi plus -minusve prominula; operculo corneo, circulari, spirali, anfractibus plurimis, confertis. So little attention having been formerly given to natural affinities, it is not surprising that in consequence of a certain accordance in gencral form, Linné and subsequent authors should have combined together shells of very various and distinct characters, while they separated others naturally allied to each other. Though this ob- servation is more particularly applicable to Linné and his disciples, it must also be acknowledged that later authors, whose general endeavours have been sucessfully directed to the improvement of natural science, have toa certain degree fallen into the same error; thus Lamarck, attending too much to external form has united in Trochus sheils which are not related to each other: for though in the character he gives of the Genus, and indeed of the family, he mentions an operculum as essential, he has united to it several, e. g. (his Z. rudians, Pileus and TT. Calytreformis) which have no operculum ; we observe also that several others, which are admitted by Lamarck, | differ from the greater part of his Trochi in having a thick shelly operculum, while several whose operculum is like that of Zrochus Niloticus and which should consequently be united to the Trochs, are found among the Turbines; whereas the only certain character by which the Trochi can be separated from the Turbines consists in the former having a horny, the latter a shelly operculum. That the Zo TROCHUS. general form of the shell cannot be regarded as its most important character, is evidenced by the fact that scarcely two species have the same precise form, though for the most part those which have a horny operculum with numerous elusely set volutions, such as Zrochus Miloticus | and Turbo Pica, have a nearly similar general form, although they are found to differ much in their peculiarities: we have shown under Turbo that the Genus Monodonta of Lamarck as well as Margarita of Leach must for the most part be united to Trochus. We think, however, that Rotella and Solarium have been properly separated from Trochus. The Trochi are conical with a more or less elevated spire, the axis of which being but slightly inclined and the edge of the base of the cone being in general angular, though it is sometimes rounded, they stand almost entirely upon the base, which as Lamarck truly says is generally flattish or even concave, as in Trochus Niloticus and concavus, though sometimes convex, as in Trochus Pica, (Turbo Pica auctorum.) Their aperture is more or less transversely depressed, (in the same degree as the base is flat, concave or convex) in general rather quadrate or trapeziform, and the dissimilarity in the form of the aperture and the operculum is remarkable, the latter being nearly circular. The edge of the aperture is oblique to the direction of the last volution of the shell and shows distinctly the inferior part of the columella, which is constantly more or less arched ; in some species the base of the columella is truncated,* and forms a more or less distinct tooth, (some of these form part of Lamarck’s Monodenta;) in others it is continuous with the peritreme and has not the least vestige of a tubercular tooth; there is, however, a regular gradation from the one to the other. Operculum horny, circular, spiral, with numerous, close- set volutions, and having the spiral line external, The Trochi are marine, and they are found almost everywhere, many are common on our own coasts, several of which are very beautiful, such as the Tr. Magus, Tr. cinerarius, Tr. ziziphinus and others. Soume of the larger _ * It is observable that although Lamarck gives this as the principal distinguishing character of Monodonta, the same character is to be remarked in many of his Trochi, TROCHUS. - species that belong to tropical climates are remarkably handsome and brilliant shells when carefully cleaned, but they have all naturally a horny epidermis which hides much of their beauty. The fossil species, which are rather numerous, belong to the newer formations, such as the Crag, the Calcaire grossier, and the green sand ; they are also found in the London clay: we have reason to believe that some species occur as low down the series of formations as the Lias. Some species of Lamarckian Carocolle have been placed with the Trochi by Linneans (e. g. the Trochus terrestris of some authors) these are, however, land shells and have no operculum; we have already stated the characters by which the Pyramidelle may be easily dis- tinguished from Trechus; but it may be necessary here to state, that the shell, called Trochus telescopium by Linneaus is more properly placed by Lamarck with his Cerithia to which it is closely allied. Fig.1. Trochus Granatum. 2. 3. 4, ——— nov. spec. 3. — Labeo, Monodonta, Lam. 6 nov. spec, 7. Operculum of Tr. Pica. 2 OL sn i ; iis} 1%) ‘ ‘ f 7 TURBO. =e TESTA turbinata, spiralis, solidiuscula, spira _plerumque mediocri, nonnunquam brevissima; apertura fere circulari, peritremate acutiusculo, basi subeffuso; operculo extus testaceo, solido, intus corneo, spirali. ——Foe ee Tut Genus Turbo in the acceptation of Linneans is indeed a mass of confusion, which has been but slightly reformed by modern writers ; the separation of the genera Turritella, Scalaria.and Cyclostoma cannot but be approved, and Clausiha ought never to have formed a part of it, because it does not at all accord with the Linnean definition of the Genus. The four above named genera being cleared off, we still find in the Lamarckian Genus Turbo a combination of shells of very various character; we think indeed that the four Lamarckian genera Trochus, Turbo, Monodonta and Delphinula require a careful revision, and we are further of opinion that the confusion at present existing in these genera has principally been caused by too great a dependance having been placed on the external form as a generic character. We shall endeavour to effect sucha reformation as appears to us desirable in these four genera, by omitting entirely Lamarck’s Monodonta and adopting the following as the distinguishing characters of the other three; and by the further separation of a rather numerous family under the already adopted name of Littorina. We would then, in the first place, separate all those shells hitherto spread into Trochus, Turbo and Monodonta, which have a solid testaceous operculum, whatever may be their external form, under the appellation of Turbo. Our Genus Trochus would consist of such other shells separated from the above named Lamarckian genera as are distin- guished by a spiral horny operculum, with numerous closely LOS TURBO. set volutions, some of which have their columella plain, without any tooth near the base; these are the Lamarckian Trochi: others have a more or less distinct tooth near the base of the columella, these are Lamarck’s Monodonta.* Delphinula appears to us to be distinguished by its circular aperture and its thickened and reflected peritreme. The operculum of Lttorda is spiral, its volutions are, however, very few and increase very rapidly in width, its columella is moreover in general somewhat depressed. It is perhaps incumbent on us to notice two endeavours to clear up these genera in part, by separating some shells from them under the names of Margarita and Marmarostoma, the first of these has been given to some small thin shells whose operculum is horny, and spiral with numerous closely-set volutions, and belongs to our Trochi; the latter has been given by Swainson to a typical species of Turbo. The Turbines vary much in general form, some being conical, with a very flat base, and keeled edge, and others having a very regular top-shape. They are in general thick, with a spire of moderate length, though sometimes very short; their aperture is for the most part nearly circular, though sometimes rather transverse and somewhat trapezoidal ; their peritreme rather sharp and not reflected, somewhat spreading at the lower part; operculum shelly, solid, externally very various in its appearance, but internally covered with a spiral horny plate ; we think it the more necessary to mention this latter circumstance as many have mistaken the rounded external surface of these opercula for the part which is attached to the animal and vice versa. It is observable that * We have been under the necessity of entirely omitting Lamarck’s Monodonta, because upon careful examination we find it merges into Trochus ; the operculum is exactly similar in both, and it is observable, that Lamarck has separated them in the most arbitrary manner, without appearing to have been himself aware of any definite character by which they might be distin- guished ; thus we find him at one time uniting the Linnean Trochus Pharaonis to his Monodonta and afterwards restoring it to Trochus; this it is well known has a very distinct tooth near the base of the columella and should therefore have formed a part of his Monodonta; and so for the same reason, should Trochus niloticus and his Turbo Pica. We regard the whole of these as legiti- mate Trochi, inasmuch as the operculum in all is precisely similar and quite different from that of Turbo, Some of Lamarck’s Monodonta belong to Littorina, and one of them is a land shell, probably related to Auricula. TURBO. Lamarck does not once mention this thick testaceous operculum, although it is characteristic of his first thirteen species of Turbo as well as of some others: it is also peculiar to some of Lamarck’s Trochi, which we conse- quently withdraw from Trochus and unite to Turbo. Another circumstance relating to the operculum is also worthy of notice, it is that the spiral line of the thick shelly operculum of Turbo is on the side by which it is fixed to the foot of the animal, whereas that of the thin horny vperculum of Trochus is external. The outer surface of these shelly opercula is very differently constructed in in the various species, and would be quite sufficient as a character by which the species might be distinguished. The Turbines are marine, and for the most part belong to tropical climates, one species alone abounding ou the shores of the Mediterranean. We have not any one on our own coasts. ‘They are mostly handsome shells, and when deprived of the outer coat and polished the pearly substance of which they are formed is particularly brilliant. The Turbo marmoratus is remarkably splendid. Few indeed are the known fossil species of this Genus, and such as we are acquainted with belong to the forma- tions of the latest period: we have one from Sicily very similar to the Turbo rugosus; another from New South Wales nearly approaching in its characters to T. torquatus and we have some fossil opercula from the vale of Ronca. Fig. 1. Turbo brevispinosus, with its operculum. 2.3. 4.and5. Various opercula. Turbo setosus. n. sp. from Valparaiso. coronatus var. n. sp. whose locality is unknown to us. PAD Zag = 4 3 { sy ues ; ‘ \ f f ; . i ‘ r Ve rT { ‘ ¥ i » ) ii ne 7 ‘ ‘ 4 \ y . v [i 3 nat : q r & > re J ‘} Ne : Wis - “ * r . a ve | « ‘ ; 4 ao 6% § hy . s \ ald A y d Fy a i} - MS ee © 4 « “4 Aa / i j ‘ a. “ 2 ‘ ia ~ eo), ’ 14% ,. e ; ; y Ps ‘ t 4 f, s ae 8 i) Oo rh eh r Wwe j } a 4 : ‘ony F 7 bed as 2. ee . Thy ‘ y ‘ Pree uae ¢ i DBRS d d ai & . 4 " St 5 te ee is te an ; % ” Wik s V2 at $i Re weag vith e *. a ae £ a i . vw. } Be ons * be er bolt By OSE ye eee hee 2 Ue ON Ba) Co ed, See ee Be . ‘i rl A ; a ease i , eer . , ; : ait a eh ? Ly 4 jj : Pett Ps Ca haha aid ' se mA ne + Cons Highs? % mn i} : any ie yh BEG aw ley 3 ; ue , A { a ey i f mar J ‘ ee i e tune bien i e us ‘ nae id ' é F gk. | bibs 2 ae eS n 4, s ay J . ' ‘ ay . ‘ { | j a y 4, 1 . ; x A r i Re he \ / LITTORINA. Fer. —3 Oo TESTA turbinata, spiralis, solidiuscula, non- nunquam tenuior; spira gradatim acuminata, nonnunquam brevissima; apertura elliptica, superneé acutiusculé; peritremate acuto; colu- mella planiuscul4; opereulo corneo, spirali, anfractibus paucis, rapidé majoribus, nucleo laterali. Tar shells which have lately been combined together under the generic appellation of Littorina have been hitherto arranged with the Turbines by Linneans and with Turbo and Phasianella by Lamarck; from both of which they are easily distinguished by their horny operculum ; _ Littorina appears to be related in the same degree to Phasianella as Trochus is to Turbo. As the name implies, the Littorinw are found on and near the shure, where they may be seen in great abundance feeding upon the sea-weed, and from whence they are collected in great quantities for food. The common Peri- winkle (Turbo littoreus auctorum) abounds on our own shores and we have several other species: the shell deno- minated Nerita littoralis by British authors, and which we believe to be Turbo retusus of Lam. is another species of this Genus very common on our shores. There are a great number of species of this Genus, found in almost all parts of the world: those of tropical climates are thinner in general than those of the more northern lati- tudes. Shell spiral, turbinated, sometimes almost turrited; mostly thick and solid, sometimes rather thin; spire for Z 53. LITTORINA. the most part gradually acuminated, sometimes very short and obtuse; aperture elliptical, rather acute at the upper part, peritreme sharp-edged ; columella rather flat; oper- culum horny, spiral, consisting of few volutions, i increasing rapidly in width, its nucleus lateral. There are several fossil species, found in the tertiary beds, and some others occur even as low as the Coral rag and the Inferior Oolite. In our plate we have represented the following: Littorina vulgaris, the common Periwinkle. pulchra, Turbo pulcher, Swainson. its operculum Fig. 1 2 oe Reps ES 4, ———— varia, a new Species from Panama. 5 6 filosa, a new species from S. America. obesa, a new species from the South Sea Islands, TURRILITES. —~< oo TESTA univalvis, libera, spiralis, turrita, conca- merata, spira sinistrorsa, gradatim acuminata, septis siphunculo perforato, marginibus sinuo- sissimis. Tuer only circumstance in which this Genus differs from Ammonites is its turrited form, the latter being spiral but having its volutions all increasing upon the same plane. There appear to us to exist, all in a fossil state only, five genera of shells with chambers whose septa are sinuous at their edges, namely, Baculites, Hamites, Turrilites, Ammonites and Scaphites, which are well distinguished by the form peculiar to each; but we think it unnecessary for the purposes of science to adopt genera such as La- marck’s Ammonoceras, founded upon a slight variation from perfect contiguity in the volutions: if we could adopt such a Genus we might for the same reasons raise almost every species to the rank of a Genus. Nautellip- sites and Ammonellipsites appear to us to be founded on no better characters, indeed we are convinced that the ellip- tical form of bothis only caused by compression in one par- ticular direction, operating at the time of their imprison- ment. Shell univalve, free, spiral, turrited, chambered, spire sinistrorsal, gradually acuminated, septa perforated by a siphunculus, their margins much sinuated. The shells of this Genus being only found in a fossil state, nothing is of course known of its animal, nor of the form of its aperture ; it appears to have lived only at one particular period, as the fossil remains only occur in 23. TURRILITES the Chalk marl. Several species abound at Ringmer in in Sussex, and Mount St. Catherine near Rouen. In our plate we have given a representation of part of a specimen which shows the form of the outer lip; we were favoured with the use of this specimen by G. Man- tel, Esq. of Lewes. CYCLAS. — ose yatta a Lantoni oni Ag un Tags % ACE vet) auedeegt ott wonld ail yoked buna: onlay es oot 7 ‘neat qudieraatog . ues att awe gb 3b tes Griviten xbiaga ‘ie Vu od tin w hatad oF att yh “Af ‘ada! oS einakrn sia 10: eoiniiis sal Beceu car eit ve qibidaians pee uoig Tl oe OF pte ee grote a) abGaars to Vit aiaaa Rye THO | beeen Aga tics! “oye faerie ortho OAR AO: snipe AG | Br annie ligt od Jo ane aGQly Ogntiodthn: Hear “ellsnabin9 erin a ‘tt STY LIFER. ee TESTA hyalina, turbinata, apice spire mucronato. Apertura subovata, superné acuminata. La- -brum acutum, sinuatum. Pallium crassum, carnosum, cyathiforme, testz anfractus ultimos obtegens. Proboscis longissima, retractilis. Tentacula rotunda, crassa, subacuminata, ad _ basin proboscidis posita. Oculi ad basin tentaculorum sessiles, minima. Branchiz stirps solitaria. Animal marinum, Asteriz cutem penetrans. Tue arrival in this country of the shell above recorded with the soft parts has afforded data for a generic charac- ter, indicating a distinct family among the Pectinibran- chiata, the form and disposition of whose mantle differs from that of any other genus in the order. This mantle, which is of green hue, is thick, fleshy and cup-shaped with a small aperture at its base, and a free posterior margin, enveloping the soft parts and the last volutions of the shell, which has thus somewhat the appearance of a small acorn set in its cup. On the ventral aspect of this mantle is the rudiment of a foot, and from the small basal aperture a retractile proboscis, which, when exserted is as long as the whole animal, is protruded. At the base of the proboscis are two thick, round, somewhat pointed tentacula; and at the base of them are the eyes, or rather ocular specks without pedicles. The branchia is placed on a single stem. At the base of the proboscis isa sphe- rical muscular stomach, and the intestine ascends into the spire of the shell, where it becomes attached to the liver, which in the species before us is of an orange colour. Mr. Cuming found this elegant parasite burrowed in different parts of the rays of the oral disc of Asterias solaris. It is almost hidden from sight, so deeply does the 424-0. STYLIFER. animal penetrate into the substance of the Star-fish, in which it makes a comfortable cyst for itself, wherein it most probably turns by the aid of: its rudimentary foot. All the specimens infested with Styliferi appeared to be in the best health though there is reason to believe that they feed upon the juices of the Star-fish. With that instinct of self-preservation imparted to all parasites, whose exis- tence depends upon that of their nidus, the Stylifer, like the [chneumon among Insects, appears to avoid the vital parts ; for in no instance did Mr. Cuming find it imbedded anywhere, save in the rays, though some had penetrated at their base and very near the pelvis. When extracted the older shells have much the appearan¢e of a milky clouded glass bubble; the younger shells are of an un- clouded transparency Dr. Turton in the second volume of the Zoological Journal p. 367, plate 11, describes and figures a shell under the name of Phasianella stylifera, adding that he found a dozen attached to the spines of Echinus esculen- ‘tus dredged up in Torbay. It is clear that Dr. Turton’s shell is not a Phasianella, for it is described as having no operculum and the similarity of the shell leaves no doubt, when joined to the parasitic habits of the animal, that it is one of the congeners of Stylifer astericola. Mr. Sowerby has furnished me with a third species, which, although its habits are unknown to me, I consider to be referrible to this Genus, and I propose to name it Stylifer subulatus; it is so beautifully transparent that in fine specimens the columella can be as distinctly seen as if there were no intervening medium; and its long apex, which consists of many close-set whorls is generally out of the perpendicular. ! W. J. Broperrr. In our plate we have represented at Fig. 1. A portion of Asterias solaris, showing the Stylifer Astericola in its cyst. 2. Stylifer Astericola, of the natural size. Zand 4. magnified. 5. Stylifer subulatus, of the natural size. 6 and 7. ~ magnified. 8. Stylifer Astericola with its animal, dorsal aspect, magnified. a. Oval orifice of the mantle. 6. generative (?) organs. CAPULUS. Montf. et Pileopsis, Lam. eq TESTA oblique conica, posticé recurva, apice uncinato, sub-spirali; apertura magna, rotun- dato-elliptica ; impressionibus muscularibus dua- bus, lateralibus, postice connatis, utraque an- - tice rotundata. Epidermis cornea, subvelutina. Tris Genus may be regarded as a remarkable instance of the importance of a correct knowledge of the animal which forms it, as well as of the characters of the shell itself. We have long entertained the opinion that the animal of this Genus (of which the well known Patella ungarica may be regarded as the type) must be a gastero- pod and consequently very different from that of De France’s Hipponyx, which is a truly bivalve shell. It may here be observed that in the bivalve mollusca the mantle envelopes the animal and lines the inside of the shell, depositing testaceous matter on its whole internal surface ; the Hipponyx is therefore a true bivalve, for its animal must be wholly enveloped in its mantle, or testaceous matter could not be deposited on all sides: but in the present Genus, which has been very erroneously united to Hipponyx by De France and Lamarck (on account, no doubt, of their general resemblance in form) there is a distinct head, with tentacula and eyes, and the branchia are arranged in a single row behind the head, there is moreover a small, nearly circular foot, by which it is usually found adhering to oysters and other shells, stones, &e. all which circumstances prove that it cannot produce a second valve, and that it is not, therefore, even related to Hipponyx. The shell itself also differs from the upper valve of Hipponyx, for in Capulus it is obliquely conical and curved backwards,* uncinate and somewhat spiral ; in Hipponyx, however, though it is obliquely conical, * Throughout his description of Pileopsis, Lamarck has mistaken the front for the back, and vice versa. 24. CAPULUS. it is not recurved, nor is it in the least spiral. We are fully aware that in full grown specimens of some of the Capuli the beak is not recurved, but we observe that in the young shells of the same species it is distinctly so. It is somewhat singular that although the Capuli are gas- teropods they do not appear to remove from the spot to which they were at first attached, but like several of the Patelle they seem to form, probably by a chemical action, a more or less deep cavity in the surface to which they adhere; this circumstance alone, should, as we think, be sufficient to distinguish the Capuli from the Hipponyces, for it is evident that an animal with a mantle capable of depositing testaceous matter, cannot at the same time erode the spot to which it is affixing such calcareous deposit. But there is a circumstance in the peculiar form of the impression made by the foot of the Capulus which it appears is difficult to understand, for the margin of this impression is sometimes more or less raised in a somewhat horse-shoe form, apparently corresponding to the muscular impressions in the lower valve of Hipponyx: we think this peculiar form may be caused by the contraction and expansion of the nearly circular foot in raising and de- pressing the shell, in order to permit the entry and egress of the sea water. Shell obliquely conical, recurved behind, with an uncinate rather spiral apex; aperture large, elliptical ; muscular impressions two, lateral, joined together at the back, each rounded in front. Epidermis horny, thick, somewhat velvety. This Genus consists entirely of Marine shells, which are frequently found adhering tv oysters and other shells ; one species, namely, the C. Ungaricus abounds on our coasts, and others are found in the Pacific and in the East and West Indies. We are not acquainted with many recent species. Several are common among the fossils of the tertiary beds. We have represented in the upper figure a specimen of Capulus Ungaricus as it commonly appears attached to an oyster shell and inthe lower figure the inside of the same species. We are obliged to the Right Hon. Lady Elizabeth Finch for living specimens brought from Tenby in January, | 1832. SOLARIUM. ~~ TESTA subdiscoidea, laté umbilicata, spira obtusé conica, apertura trapeziformi, peritremate tenui, acuto, umbilico margine spirali crenato; oper- culo corneo, sub-spirali. Tue shell commonly called the Staircase Trochus has, from the time of its being first known, been deservedly cele- brated among collectors, on account of the beauty and symmetry of its external form and its elegantly crenated spiral umbilicus. This was placed by Linné among the Trochi, to which indeed it appears to us to be nearly related. It has, however, been since separated, and forms conjuintly with its more closely related species the modern Genus Solurium. This we have adopted without hesita- tion, because we find a number of shells distinguished specifically, but yet agreeing in certain generic charac- ters which therefore in our view, form a natural genus. The shells forming this Genus are usually of a some- what disceidal form, with an obtusely conical spire, the lower edge rather sharply angular, and the umbilicus broad and deep: they vary, however, occasionally, in a slight degree from this general form, having the spire sometimes of a rather more lengthened conical form, the basal edge more obtuse, angular, and the umbilicus broad and deep. The umbilicus has, in almost all instances its spiral lower margin strongly and closely crenulated, though occasionally this also is subject to some variation, asin the S. patulum, for example, in which this spiral lower margin of the umbilicus has only a few small grains placed here and there at a distance from each other. The aperture is trapeziform, with more or less rounded angles, and a thin sharpish peritreme. A thin horny epidermis covers the shell in its natural state; this is either very AG2, SOLARIUM. deciduous or must in general have been carefully cleared off before the shell is brought to England, for it is scarcely ever to be seen. The operculum which is horny, varies in form, according nearly in shape with the aperture; it is foliaceous and more or less distinctly spiral; in one species its foliated edge forms an elevated spiral cone on the outer side; this outer side is, however, flat in the common species; the inner side in both species has an irregular, somewhat lateral tubercle. Solarium appears to be most nearly related to Tro- chus; its recent species are not numerous, but they seem mostly to belong to tropical climates: a few fossil species occur in the tertiary beds; and there are some fossils be- longing to the lower beds of oolitic formation, and even as low as the Mountain Limestone which resemble them very nearly; these form the genus Cirrus of some authors, and does not appear to us to possess any characters by which it may be generically distinguished from the Trochi, Turbines or Solaria. We have given two views of Solarium perspectivum, and of its operculum; and also a representation of the small spiral operculum of S. variegatum. APLYSIA. TESTA clypeiformis, tenuis, pellucida, przecipue cornea, compressa, posticé acuminatiuseula, dorso convexo, anticé lamellari, rotundata. Retarep to Dolabella, and united to it hy DeFerussac, who has favoured naturalists with a very complete account of the family. It is remarkable that the shell, which consists almost entirely of horny epidermis, is nearly covered by the integuments of the animal; it seems to serve aS a protection to the pectinated branchie. The animal is much larger than the shell, and when it rests not unaptly resembles the hare crouching upon the ground, whence it has the common appellation of Sea Hare, Lievre marin, &c. Its singular structure, together with its ana- tomical peculiarities are well described by Cuvier in his Memopires sur les Mollusques. It may not, however, be uninteresting here to mention that when disturbed this animal transudes a quantity of purple liquor which has been supposed to possess depilatory properties, but which we apprehend to be rather intended to conceal the animal from its enemies. Shell clypeiform, thin, pellucid, consisting for the most part of horny epidermal matter, with a very little testaceous matter within; it is of a somewhat oval shape, convex on the back, rather acuminated at the posterior extremity, rounded and very thin and lamellar in front. The Aplysia, which have been improperly called Laplysiz* are marine; they appear to belong to all eli- : * Lamarck has very improperly endeavoured to perpetuate an accidental error in the name given by Linné to this animal, by continuing to call it Laplysia and bringing a false charge against later naturalists 0 Aplysia. The ancient word is Aplysia, as Cuvier has shown, “ that which is unclean.” f changing it to which signifies, ZA ¢3, APLYSIA mates. Several are found on our own shores. We have never met with any fossil remains of the shell of this Genus. We have figured in our plate Fig. 1. Aplysia Petersoni, 2 views. Brasiliensis ? concava, nobis.. quadrata, nobis. 2. 3. 4. FUSUS. = 6 TESTA fusiformis, turrita, anfractibus plurimis, _ plerumquerotundatis, canalirecto, plusminusve elongato, apertura elliptica ; operculo corneo, - infra acuminato, nucleo inferiore. Anoturr of those genera which has properly been sepa-~ rated from the Linnean Murices, from which it is suffici- ently distinct. The species of this Genus are for the most part more or less regularly fusiform, with a turreted and gradually acuminated, usually pointed, though occasionally mammillary spire, consisting of numerous, generally round- ed volutions, which are frequently transversely ribbed and spirally grooved on their outside; aperture elliptical, running into a more or less Jengthened straight canal; operculum horny, with its nucleus at its acuminated lower end; a thin horny, more or less rough or velvety epider- mis, usually covers the shells of this Genus in their natu- ral state. [In this Genus, as in Pleurotoma, there are several variations in form, which we will here endeavour to des- cribe, and which we will illustrate in our plate: the first, which may be ealled the typical form, as being that from which it takes its name, has its spire and its canal of equal length, its aperture elliptical, its last volution ventricose, and the canal narrow, commencing by a sudden contrac- tion at the base of the aperture; Fusus Colus, and Fusus nicobaricus are examples of this form: next we may men- tion those which approach in form to our Pyrule, and many of which Lamarck has united to his Pyrule, these have a shortened spire, a somewhat lengthened canal, and the last volution is ventricose at its upper part, being some- “times tuberculated, and even having strong vaulted spines around the upper part of the volutions; for examples of FUSUS. this variation observe F. colosseus, F. Cochlidium, and Pyrula Vespertilio, and others of Lamarck. A third varia- tion in form, approaching to Buccinum, consists of a number of species whose spire is more lengthened than the canal, which is short, and not quite straight; the greatest gibbosity of the shell in these is below the middle ; F. lignarius, F. nifat, F. articulatus, &c. are characteristic of this variation: the fourth variation in form consists of those species which, having in general nearly the same form as the first mentioned variation, namely, that of Fusus colus, and which have two or three small horizontal folds at the base of the columella, immediately above the contraction of the canal ;* F. infundibulum, F. craticula- tus, F. polygonus, F.cariniferus, F. lineatus, are some of the species belonging to this division. It is worthy of remark respecting the five last mentioned shells that Lamarck had formerly placed the three first among the Fusi, and the two latter among the Fasciolarie, though at length he placed all five among the Turbinelli. Other variations in form there are, which we rather hesitate to unite with Fusus, partly because we are but slightly acquainted with them, and partly because they are so peculiar, that we Si Si i hs EN |e fear we might be charged with forming an incongruous — association by so doing, inasmuch as we should he scarcely able to convince naturalists of its propriety. These are, first, the Turbinella rustica of Lamarck, which is a thick, solid, oval shell, with a gradually tapering short spire, and a short canal, in its general shape it is much like Fusus Bulbulus of Lamarck, a very common Fossil in the London Clay, and the Calcaire grossier, but differs from that species in having three small: horizontal folds at the base of the columella: secondly, two other shells named by Lamarck, Turbinella leucozonalis and T. cingulifera: we believe these two to be really only varieties of one species, which is very peculiar, and forms a sort of link connecting the Fusi with Lamarck’s Monoceros cingula- * Under the article Fasciolaria in this work we have suggested that it ‘might not be improper to separate these asa distinct Genus ; we are not however satisfied of the necessity of adopting this proposition ; and we place them with Fusus as being incontrovertibly more nearly related to that Genus than to Fasciolaria or Turbinella, to both of which some of them have been united. FUSUS. tum; the circumstance for which it is remarkable is that it has a more or less distinct tooth projecting from near the base of the outer lip, which is sometimes much length- ened, though it ismore commonly nearly obsolete; thirdly, several species nearly agreeing in form with the last men- tioned, though differing in the characters of the colu- mella, near the center of which is a remarkable tubercular prominence, they have also three small horizontal folds at the base of the columella. The opercula of all the above are alike in form, only differing in thickness a little. We have already, under the article Murex, shown that the M. Magellanicus should be arranged with the Fusi, it nearly resembles in form our common Fusus des- pectus or antiquus (Murex antiquus, nonnull.) There isa very remarkable shell, commonly known under the name of Murex aruanus, Linn., but called Fusus proboscidi- Jerus by Lamarck, the apex of its spire for about three- fourths of an inch from the commencement is cylindrical, consisting of several volutions; this shell grows to be much the largest of the genus we are acquainted with, we have seen it two feet in length.* The Fusi are ail marine, and they do not appear to be confined to any particular part of the globe; the species are very numerous and several very common on our coasts. The fossil species are also very numerous, several of them abound in our London Clay formation, and in the Calcaire grossier, and they are chiefly found in the tertiary beds. The F. contrarius of Lamarck is characteristic of the English Crag, and a very nearly similar species is found in Sicily, both in a recent and fossil state. Our plate represents at Fig, 1. Fusus longissimus, young. — aculeiformis —- Colosseus, young. —- striatus. —— Nifat. Sapa ee 2 * Linné refers to Gualt. Test. t. 47, f. B. for a representation of his Murex Aruanus, which certainly is not the Fusus proboscidiferus of Lamarck. ZES, ive DELPHINULA. —e3e— TESTA subdiscoidea, vel subconica, umbilicata, solidiuscula, anfractibus asperis aut angulatis; apertura integra, rotundata, peritremate, con- tinuo, incrassato, subreflexo ; operculo corneo, spirali, anfractibus numerosis, confertissimis. Decrurnuta is a Genus which has been separated by La- marck from the Linnean Turbines, taking T. Delphinus as the type. In it he has associated shells of great diver- sity of character, such as the D. laciniata, D. trigonostoma, D. conica, and D. Warnii. The group thus formed does not appear to us to be quite natural, and we would render . it more so by taking away D. trigonostoma and placing it with the Cancellariz, its natural associates. We would take away D. conica also, if we knew where to place it, but it is a fossil and we are not well enough acquainted with its affinities to venture an attempt at altering its lace. r The name of Dolphin in English and Delphinula in Latin has been given to the D. laciniata, as we suppose from some fancied resemblance to a cetaceous fish. The Delphinulz vary in general form from nearly discoid to somewhat conical; they are umbilicated and generally of a thick solid substance, the volutions few, more or less rough and angular; the aperture entire, round, with a continuous, thickened and somewhat re- ‘flected peritreme: operculum horny, like that of the Trochi, with very numerous and closely-set volutions. The species which may with propriety be placed in this genus are not numerous, as far as we know there may be about a dozen recent and as many fossil, most of these latter belonging to the tertiary beds. Several of these which have been found in Normandy are most elegant fossils; such are D. Gervillii and D. Warniti. Fig. 1. Delphinula liciniata, _ 20 ——_--——— its operculum. crenata, nobis, » $3 ALG, le a RON ie abhi ge ROY oa of her “phe ae ae , + analy’ Svehla! la pee Aas, ie Ge 0° alg obidtien iipuiiay | Se onal oF ee wae ave We as eg eae i le” ie # aay “adieu pes atoms: aie ae Lal hayes ave ‘ Frost BULLA. met hyp im Bulla and Bullea, Lam. “oo TESTA plerumque tenuis, levigata, ovata, vel oblonga, plus minusve convoluta, spira brevi, vel depress, vel coneavi; apertura maxima, feré longitudinem testz zquante, plerumque longitudinali, nonnunquam feré transversa, raro lineari, antice latiore : epidermide tenui. In uniting the Bulleze of Lamarck with his Bulle, we think we are justified by the consideration that. there is so complete a transition in form from the oval and ventricose Bullz, such as B. Ampulla, to the only slightly convoluted, and almost unrolled Bullze, that it is impossible to draw the line of separation between the two. Perhaps we may be blamed by Malacologists for thus uniting shells whose animals apparently differ very materially, we think, however, that whoever will carefully examine the animals of both, will be convinced of the propriety of this union, for a general resemblance and affinity will be observed and it will be found that the principal points of difference will be analogous to those very specific circumstances in which the shells differ. The Genus Bulla as it has been established by Cuvier, Lamarck and others consists of only a very small part of the Linnean Bulle. We have already shown how widely separated from genuine Bulle are the Lamarckian Acha- tine, Pyrule, Ovule and others which Linné and his followers combined with them, wherefore we need not here repeat the description of their distinguishing characters, but may immediately enter upon the characters of Bulla as we have here considered it, as consisting of Lamarck’s Bulla and Bullza combined, — Lu; BULLA. The Bulle are generally oval, more or less spirally convoluted univalves, sometimes having a distinct, though short spire, and not unfrequently a depression in ‘place of the spire: they are mostly thin, and generally varied in their coloration, though occasionally of an uniform colour and sometimes even colourless; aperture generally large, and nearly as long as the shell, for the most part longi- tudinal, though sometimes almost transverse, im most species ‘wide and much wider anteriorly or at the lower part than at the upper, in some instances very wide and spreading, and very seldom narrow and almost linear, always effuse at the lower extremity. On one side the Genus Bulla appears to approximate in general appearance to Tornatella, some of its species, the B. Amplustre, for example, having nearly the same form ; and on the other side to the Aplysiade, the B. aperta approaching very nearly in form to the Dolabelle. A circumstance remark- able in the animal of the Bulle is the form and structure of the stomach, which in most of them eonsists of three strong shelly pieces united by powerful adductor muscles ;, we suppose such a structure to be necessary to their existence, for they are exceedingly vor acious as is evident. from the fact that the animal of B. aperta is sometimes distorted by having swallowed entire a Corbula Nucleus, which is a very thick and strong shell, nearly equal i in size to itself. The Bulle are marine, and they appear to belong to, nearly all climates; several are common on our own coasts ; very few of them grow tobe so large as a Walnut and they are for the most part much smaller. Fossil species are only to be distinguished i in the tertiary beds and in the green sand. ae our plate we have given representations of Fig. 1. Bulla aperta, (Bullewa, Lam.) — virescens, nobis- — Lignaria. —— Ampulla. — calyculata. —— Physis. cylindrica. —— Amplustre. oD nh 219: an Nah gs SOLENELLA. —<—te TESTA ovalis, squivalvis, subzxquilateralis, compressa, nitens, epidermide olivaceo-viridi, tenui, induta; dentibus, cardinalibus nullis, lateralibus anticis, in utraque valva, tribus ad quatuor, lateralibus posticis plurimis, seriem rectiusculam efformantibus, omnibus parvis, acutis; impressionibus muscularibus duabus, lateralibus, subdistantibus ; impressione pallii sinu magno; ligamento externo, elongato. (nS * An interesting Genus partaking of the characters of Nucula and Solen, so that it may be regarded as the link connecting the two families of the Solenacee and the Mac- tracee. It belongs to the Solenacez, having the external ligament and the large sinus in the muscular impression of the mantle, but resembles Nucula, which belongs to the Mactracex in having the lateral teeth divided into series of minute and pointed teeth, differing from it, how-. ever, in not having an internal ligament. Shell longitudinally oval, equivalve, nearly equilateral, compressed, shining, covered with a thin olive-green epi- dermis ; it has no cardinal teeth, and in each valve only three or four very small anterior lateral teeth ; the posterior lateral teeth, however, are numerous and form a nearly rectilinear series, they are moreover small and sharp pointed, those of one valve exactly fitting between those of the other; this series of small teeth is placed immedi- ately below the fulcrum to which the external, elongated ligament is attached... The muscular impressions are two, lateral and rather distant, and there is a large sinus in that of the mantle. A A few specimens of this very interesting bivalve were dredged by Mr. H. Cuming at Valparaiso. It is the only species we have seen, but Mr. Cuming informs us that he has met with another. We have named it Solenella Norrissii. 248. CLASS. PTEROPODA. nate WE have thought it desirable, in order to give a general view of the family, and at the same time to save as much Space as possible, to assemble such genera of the Ptero- _poda as we are able to illustrate, in two plates. This isa smallfamily and may be more easily illustrated consecutively, particularly as the various genera of which it is composed resemble each other to a great degree. Scarcely any of the Pteropoda were known to Linnean writers on conch- ology, the only one that we recollect in any Linnean work before the modern improvements of Cuvier, Lamarck, &c. being the Hyalea tridentata which is in such works named Anomia tricuspidata: than which nothing could be much more absurd, since, independently of the important dif- ferences existing between the animals, it is well known that the Linnean Anomiez are bivalves, while the Hyalea and all the Pterupoda are univalves. Cuvier in his Me- moires sur les Mollusques, has shown that the Pteropoda are a separate family or class, distinguished by certain peculiarities, the organs of locomotion being shaped like wings, the whole of them being free swimmers, and their shells in general having a peculiarly transparent, brittle, and vitreous character. The genera of this family which we shall here illustrate, are Hyalea, Cleodora, Limacina, Creseis, Vaginula, Cuvieria, and Cymbulia. They are mostly found swimming about in the sea in all climates, and in some they abound to such a degree that they are said to be the chief food of the cetaceous mammifera, Besides the above-named genera, there are others belong- ing to the same family, which are, however, destitute of shell; we suspect, moreover, that the little tr ansparent shell called Dentalium Pans by Montagu, will prove, when its animal is known, to belong to this family. The whole of the Pteropoda are marine, and they appear to belong to all climates. LG. PTEROPODA. Hyatza. Fig. 1. Testa subglobosa, tenuis, hyalina, fragillima, dorso superné subrostrato, infra tridentato, dente centrali validiore, apice pervio; ventre superné gibboso, breviore, aper- tura lineari, supra-ventrali, ad lateres continua. Tae Hyalew are in general nearly globular, very thin, transparent and brittle; they may be regarded as consti- — tuted of two parts, united together at the lower edge, one part being apparently dorsal, larger than the other, re- flected and subrostrated at the upper end, tricuspidate and united to the ventral portion by the edge below; the central tooth being the longest, and open at the end; the other part appears to be ventral, which is shorter and gibbous above; the aperture is linear, continuing between the dorsal and ventral parts at the upper end, and on both sides. - _ Occurs in a fossil state in Sicily. Cieopora. Fig. 2. Testa inverse pyramidalis, hyalina, incolerata, tenuissima, fragillima, dorso superné rostrato, infra acuminato, ventre superné breviore, lateribus acuminatis, aper- turd magna, supra-ventrali, ad lateres coarctata. Tux Cleodore differ from the Hyalex principally in the form of their shells; they are even thinner, more trans- parent, more brittle and altogether more delicate; and they have the appearance of the thinnest and most trans- parent glass. ! Shell inversely pyramidal, transparent, colourless, extremely thin and fragile, dorsal portion rostrated at the upper extremity, and acuminated at the lower; ven- tral portion shorter above, angular and acuminated on the sides; aperture large, dilated in the middle, smaller and contracted on the sides, placed above between the dorsal and ventral portions. PTEROPODA. Limacina. | Fig. 3. Testa tenuis, fragilis, spiralis, discoidea, lateribus umbili- ” catis, dorso et subtis carinata, carina membranacea, lamellari. We have been favoured with this very curious little shell from Messina, by the Rev. Robert Wilson. It has exter- nally much the appearance of a very diminutive umbilicated Nautilus. It differs from the other Pteropoda principally _ in being convoluted; and it may be described as a thin, fragile, spiral, discoid shell, umbilicated on both sides, and carinated on the back and below, with a membrana- ceous lamellar keel. CresEis. Fig. 4. Testa inverse pyramidalis, hyalina, tenuissima, fragillima, subtus acuminata, superné aperta, parte dorsali lon- giore; lined dorsali semitorta ex vertice ad basin de- currente. SHELL inversely pyramidal, transparent, very thin and brittle, pointed at the lower end, wider and open at the upper, dorsal part more lengthened and pointed, with a partly twisted line running from the vertex to the base. Found in the Mediterranean. Vaainuta. Fig. 5. Testa inverse pyramidalis, tenuis, fragillima, medio ven- tricosiusculo; infra acuminata, apertura minima; superné lateribus exqualibus, apertura magn4, ob- longa. : SHELL of an inversely pyramidal form, thin, very brittle, rather ventricose in the middle, acuminated and having a very small aperture at the lower extremity; upper end with both sides equal, and a large obiong aperture. Only known in a fossil state, in tertiary beds near Bordeaux. 2 SU, PTEROPODA.~ Cuvieria. Fig. 6. Testa subcylindrica,. vitrea, hyalina, tenuissima, fragil- lima, medio ventricosiuscula, infra obtusa, clausa, superné subcompressa, apertura magna, neath latere dorsali elevatiusculo. SHELL subcylindrical, glassy, transparent, very thin and brittle, rather ventricose in the middle, obtuse and closed below ; slightly compressed at the superior extr emity, with a ‘large oblong opening, dorsal mar ans rather higher than the ventral. | 7 Found in the Mediterranean. CymBuuia. Fig. 7. Tus Pteropod of which we have added three representa- tions, with its boat-shaped integument, has no shell, though it has usually been described as having one. We do not therefore give any description of it, and only observe that the above-mentioned boat-shaped integument, which has been described as a gelatinoso-cartilaginous shell, is an exceedingly transparent horny substance, not in any wise testaceous. This with its animal is occasion- ally thrown ashore at Nice. ANATINELLA. oa TESTA ovata, wzquivalvis, subequilateralis, latere antico rotundato, postico subrostrato, subtruneato; ligamento interno, processus cochleariformi affixo, dentibus duobus eardi- nalibus in utraque valva ante processum positis: impressionibus muscularibus duabus, antica oblonga, irregulari, postica subcireulari; impressione musculari pallu integra: appendice cardinali interna nulla. Opp valves of this remarkable shell were brought to England many years since by the late celebrated Dr. Solander, which, however, being imperfect, it was im- possible to place with certainty. The arrival of a few perfect specimens lately from Ceylon has enabled us to ascertain the characters by which it is distinguished from other genera to which it appears most nearly related. We have named this Genus dnatinella on account of its'general resemblance to Anatina; from that, however, it may be known by its being destitute of the testaceous cardinal appendage and the sinus in the muscular impression of the mantle which characterizes that Genus. From Mya, Lutraria and Amphidesma it is also distinguished by having no sinus in the pallial impression. In having the pallial impression entire, and in the characters of the hinge it approaches somewhat to Crassatella, itis not, however, a ponderous, but rather a thin shell, moreover, it has not the thick epidermis nor the lateral tooth of that Genus. We think it properly placed near to it. 2 ob, oon ANATINELLA. Shell ovate, equivalve, nearly equilateral, the anterior side being rounded, and the posterior slightly beaked and subtruncated. The ligament is internal, and fixed to a spoon-shaped process in each valve, on the anterior side of which are placed two rather elongated cardinal teeth. Muscular impressions two, lateral, distant, that which is anterior being oblong and irregular, and the posterior being nearly circular. Muscular impression of the mantle entire, without any sinus. No clavicle or testaceous appendage before the ligamentiferous process. Only one species is known, which is found in the sands on the coast of Ceylon. eres ee CUMINGIA. =<2oe~ TESTA bivalvis, ineequilateralis, sequivalvis, latere antico rotundato, postico subacuminato; dentibus, cardinali in utraque valva unico, parvo, antico; lateralibus in altera valva ad utrumque latus uno, valido, in altera nullo: | ligamento interno foveole subcochleari- formi affixo; zmpressionibus muscularibus dua- bus, lateralibus, distantibus, antica irregulari, oblonga, postica subrotundata, tmpressione musculart pall sinu maximo. a AN interesting new Genus of bivalves which should be placed near to Amphidesma. It is remarkable for the dissimilarity of the hinge of the two valves, one having a strong lateral tooth on each side of the ligament and the other being entirely destitute of lateral teeth. Having only met with a single small West Indian species we could not venture to consider this Genus as established, until Mr. Cuming showed us several species in his rich collection of South American and Pacific shells, one of which is sufficiently large to show the characters distinctly. The Cumingia are inequilateral, equivalve bivalves, with the anterior side rounded and the posterior rather acuminated. A single small anterior cardinal tooth is observable in each valve: and there is one strong lateral tooth on each side of the hinge in one valve, but no late- ral tooth in the other valve; the ligament is internal and affixed to a somewhat spoon-shaped pit in each valve. The muscular impressions are two in each valve, they are lateral and distant, that which is anterior is irregular and oblong ; the posterior is rounded. There is a very large sinus in the muscular impression of the mantle. The shells of this Genus are marine, they are found in the sand in the fissures of rocks, and as far as we yet know they are tropical. Not known in a fossil state. 202. RISSOA.