ee ed ~~ 3 ew ey eg a Hie SRR. a BE ibe “TonGGIs TEX TL OOi-, ike a yo axe wn ; ARRANGEMENTS ey" east - , e or ; ‘: gs, a An os es x Oy peor YL OPFRIODELLD D@ OPO. “OF TECHNICAL TERMS.” ah ge sa % i its * p 4 ae > ~ ar, Go) “ oe 4 pe iy 4 J Ct ae ¥ N, 2 Scar ERD sieges 4) = 7 BT SRE RANE as alpen sb GEAAt: >, CRBETS AN NEP P8 SIDENE OF DHE ROV AN aL erie yoqury. coc Bee. Be, >) ee, J 5 ‘ a ee Soe DPD IIT EM PPPOE Pn oR ; ey Division of Mollusks Sectional Library THE CONCHOLOGISTS TEXT-BOOK. as fo a a / CONCHOLOGISTS TEXT-BOOK EMBRACING THE ARRANGEMENTS OF LAMARCK AND LINNAUS TiS7 x WITH A ww iV SIOZ £2 OF Mollual Oyiry vErsti € ey ‘ereled, f Secti werkt 3 iJ a, rary GLOSSARY OF TECHNICAL TERMS. By CAPTAIN THOMAS BROWN FS LLOW OF THE LINNEAN SOCIETY, MEMBER OF THE WERNERIAN, KIRWANIAN AND PHRENOLOGICAL SOCIETIES, AND LATE PRESIDENT OF THE ROYAL PHYSICAL SOCIETY, &c. &c. &c ILLUSTRATED BY NINETEEN ENGRAVINGS ON STEEE. ne TRIRE TE NT — f. wee LE SON; POURTM BDITLOMS ray 22 198 GLASGOW: ffs SHAR ARCHIBALD FULLARTON & CO.; aw W. TAIT, EDINBURGH; W. CURRY, JUN. AND CO. DUBLIN AND ORR AND SMITH, LONDON. —_— MDCCCXXXVI. CCW B. ys -~ rs vay 4 = ieee OG MOHD AOD, a | rie reas ia 7 ia Wil FE & Ly: in ot bey } i) Lee ee a op ’ ww tO SIR THOMAS DICK LAUDER OF FOUNTAINHALL, BART. FELLOW OF THE ROYAL SOCIETY OF EDINBURGH, MEMBER OF THE ANTIQUARIAN AND WERNERIAN SOCIETIES, ETC. ETC. ETC. THE FOLLOWING WORK IS INSCRIBED, AS A MARK OF RESPECT, FOR HIS SCIENTIFIC ZEAL AND ACQUIREMENTS, BY HIS OBEDIENT FRIEND AND SERVANT, THE AUTHOR. _ Edinburgh, May, 1833. CONTENTS. PREFACE, ° : ‘ : 3 Introductory, : 2 Explanation of the nant of shales Multivalve, Bivalve, Description of plate IV. Ledges of the! Ean Genera of Bivalves. Univalve, Of the Linnean Genera, Order I.—Multivalve Stelle: II.—Bivalve Shells, IIJ.— Univalve Sheils, Table of the Linnean Genera of shells, with leans Divisions. Lamarck’s Genera of Siellg, Cass a ee Motwusca, Order I.—Heteropoda, II.— Cephalopoda, III. — Trachelipoda, IV. — Gasteropoda, : : V.— Pteropoda, : ‘ i - Cuiass SECOND.—COoNCHIFERA, - : Order I. —Monomyaira, ° F . II. —Dimyaira, Crass THIRD.—CIRRIPEDA, ‘ : 3 5 Order J.— Peduncuiata, B IT.—Sessilia, ; - Page 104. 106 106 118 148 148 150 vill CONTENTS. Division III.—Articulata, : c Crass Five.—Annelides, Order I. —Sedentaria, : II. Antennate, : Method of Collecting and Cleaning Shells, Glossary of Terms used in Conchology, Index to the Classes, Orders, and Genera, 153 153 153 159 160 171 77 PREFACE. Tue study of Conchology has, by many, been considered as trifling, and tending to no useful purpose ; but such an opinion could only emanate from persons who were ignorant of its great importance in a geological point of view, as fossil shells, coral, and wood, are the only true remaining Mrpats or Cre- ATIon—as Bergman elegantly expresses himself. ‘These often retain the exact figure of their primitive state. By their aid therefore, we are enabled to identify strata of the older fer- mations, or that which is of antediluvian origin. For none of these fossil species now exist in a living state, having all perished in the wreck of the former world. < By these me- dals,” says Parkinson, “we are taught, that innumerable be- ings have lived, of which not one of the same kind does any longer exist,—that immense beds, composed of the spoils of these animals, extending for many miles under ground, are met with in many parts of the globe,—that enormous chains of mountains, which seem to load the surface of the earth, are vast monuments, in which these remains of former ages are entombed,—that, though lying thus crushed together, in a rude and confused mass, they are hourly suffering these changes, by which, after thousands of years, they become the chief constituent parts of gems; the limestone, which forms the humble cottage of the peasant; or the marble, which adorns the splendid palace of the prince.” From the connect- ed examination of fossils, and of the strata which contain them, much valuable information may be expected to be ob- tained respecting situations in which useful substances may be found. To trace the structure, and investigate the uses, of animals which inhabit sheils, is not the least amusing and instructive part of the study of Conchology. As the Almighty has x PREFACE. formed nothing in vain, these creatures, so low in the scale of being, must have particular uses allotted them in the plan of creation. Conchology has ever been a favourite pursuit, from the beauty and elegant structure of shells, and the ease with which they can be preserved. When our “ Elements of Conchology ” were first penned and published—seventeen years ago—we were young both in years and science; we then held the opinions and arrangements of Linneus as sacred; and consequently dreaded the new sys- tems, and widely developed views of the French school of Natural History, which threatened to overturn the system that had been the delight of our youthful studies. Since that period, our ideas have gradually expanded, and a conviction of the superior classification of the French School has settled in our mind. This was not, however. effected of a sud- den, but brought about as our investigations increased: besides, we had the benefit of frequent communings with the talented and gifted Baron Cuvier, Geoffroy St Hilaire, Latreille, Blain- ville, and Lamarck, the father of modern Conchology, whose method is the basis of the following pages; only that we have pursued the descending scale, and enlarged by the addi- tional genera of some other testaceologists, as well as our own. The arrangement of Lamarck is strictly preserved in the orders and families, and the new genera have been placed as nearly as possible in the situations which they would naturally occupy in his system. The Linnean arrangement was long followed as the best, and is still adopted by many naturalists. Since his time, how- - ever, the immense accumulation of new species, with charac- ters which are likewise new, renders the task of classifying them according to his method, extremely difficult, if not im- practicable. We have, nevertheless, given his arrangement, as well as that of the modern school, leaving it to the decision of the student which he will adopt. THE CONCHOLOGIST’S TEXT-BOOK. INTRODUCTORY. ConcHoLocy or TEsTACEOLOGY, is that department of Natu- ral History which treats of animals with a testaceous covering or shell. The richness and variety of colours, the fine polish, the beauty and elegance of form exhibited by shells, have always excited admiration, and procured for them a conspicuous place in the cabinet of the curious collector. But whatever interest the pursuit of this branch of knowledge may have excited, in this point of view, and the singular folly and extravagance of mankind, in the high prices which have been paid for rare and beautiful shells, this is the least striking feature of their history. Other and more important reasons render the study of Conchology an agreeable pursuit. The animals of many kinds of testaceous shells furnish an excellent and nutritious food. Some tribes supply the table with a delicate luxury. Other shells, as those of mother of pearl, afford materials for ingenuity and art, in pre- paring it for various purposes: and the pearl itself, often the rival of the most precious gems in the estimation of mankind, is the production of testaceous animals. Its nature and mode of formation, therefore, cannot fail to be objects of curious investi- gation. Even the pernicious effects of some species of this tribe of animals, demand the attention of man, in studying their nature, tracing their history, and in providing a remedy against their poisonous properties. The Snail ravages the garden and the field, and marks its progress with the destruction of some of the fairest of the vegetable kingdom; and the Ship-worm, the iZ INTRODUCTORY. dread of the mariner, appears an insignificant instrument in the hand of Providence, in humbling the glory and pride of man, in demolishing, by its unseen labours, the noblest efforts of his in- genuity and skill. Conchology has been sometimes confounded with Crustace- ology, but the slightest attention to the subject will at once dis- cover the obvious difference which exists between these two classes. Nature has not only well defined them by the compo- sition of the shells, but also by a manifest difference in the con- struction of the animals which inhabit them. Testaceous shells are composed of carbonate of lime, combined with a small por- tion of gelatinous matter ; while those of the Crustacea are com- posed of phosphate of lime, along with the animal matter. Tes- taceous shells are, in general, permanent coverings for the in- habitants, and the animal is of a soft and simple nature, without bones of any kind; and attached to its domicile by a certain ad- hesive principle, possessed by some of the muscles. On the other hand, shells of crustaceous animals are cast, and renewed annually. The animals are ofa fibrous texture, with articulated limbs, and covered, as it were, in a coat of mail. Besides, the shells of crustaceous animals are produced all at one; those of the Testacea, evidently are formed by the animal gradually adding to them either annually or at least periodically ; as may be dis- tinctly seen in the common muscle: and all shells, strictly so called, are composed of layers, which is not the case with the coverings of Crabs and their congeners. This may be easily proved by taking a shell and filing it slowly, when the different layers are very perceptible ; or put a Muscle-shell into the fire, when it will shortly begin to crackle and divide into separate laminze. We have numberless instances of shells, both sea and land, which have been broken, and firmly mended by the animal; almost every collection affords specimens of mended shells. Pi The terms Conchology and Testaceology include all animals which have a testaceous covering, whether they inhabit the sea, land, or fresh-water. Chemists have divided shells into two classes. The first are usually of a compact texture, resembling porcelain, with an en- amelled surface, and are in general beautifully variegated. ‘Those composing this class are called, porcelancous shells, which in- 7 INTRODUCTORY. 13 cludes the genera Conus, Cyprza, Voluta, &c., of the Linnean arrangement. The second class consists of shells generally covered with a strong epidermis or skin, below which lies the shell in layers, and composed entirely of the substance well-known by the name of mother-of-pearl. In this class are the fresh-water Mus- cles, (the Mytilus Cygneus and Anatinus of Linne,) the Haliotis or ear-shells, the Turbo, and several of the Trochus tribe, &e. The porcelaneous shells, contain a very small portion of soft animal matter, and those of the second class a very large propor- tion.* Shells, therefore, are only the habitation of soft animals called Vermes, or Worms, which constitute the third order of Linnzus’s sixth class of animals. According to that author, the animals have been arranged into ten genera, as follow: 1. Limax; 2. Doris; 3. Spio; 4. Amphitrite; 5. Terebella; 6. Nereis; 7. Ascidia; 8. Tethys; 9. Triton; 10. Sepia. 1. Limax.— Body oblong, creeping, with a fleshy kind of shield above, and a longitudinal flat disk beneath ; aperture placed on the right side, within the shicld; feelers four, situate above the mouth, and an eye at the tip of the largest ones This genus is what is generally termed the slug, or snail. 2. Doris.— Body, creeping, oblong, and flat beneath; mouth placed below, on the fore-part; vent behind, on the back, and surrounded by a fringe; feelers, two and four, seated on the upper part of the body in front, and retractile within their proper receptacles. 3. Srro.—Body projecting from a tube, jointed and furnished with dorsal fibres ; peduncles, or feet, rough with bristles and placed towards the back; feelers two, long, simple; eyes two, oblong. 4, AMPHITRITE.— Body projecting from a tube and annulate ; peduncles, or feet, small, numerous ; feelers two, approximate, feathered ; no eyes. 5. TEREBELLA.— Body oblong, creeping, naked, often inclosed in a tube, furnished with lateral fascicles, or tufts, and branchiz ; mouth placed before, furnished with lips without teeth, and * See Thomson’s System of Chemistry, Vol. V. p. 507. B 14 INTRODUCTORY. protruding aclayate proboscis ; feelers numerous, ciliate, capil- lary, seated round the mouth. 6. Nerers.—Body long, creeping, with numerous lateral peduncles, or feet, on each side; feelers simple, rarely wanting ; eyes two or four, rarely none. 7. Ascrp1a.—Body fixed, roundish, and apparently issuing from a sheath; apertures two, generally placed near the upper end, one beneath the other. 8, Treruys.—Body detached, rather oblong, fleshy, without peduncles ; mouth with a terminal cylindrical proboscis, under an expanded membrane or lip; apertures two, on the left side of the neck. 9. Trirron.—Body oblong; mouth with an involute spiral proboscis ; tentacula, or arms, twelve, six on each side, divided nearly to the base, the hind-ones cheliferous. 10. Srpra.— Body fleshy, receiving the breast in a sheath, with a tubular aperture at its base; arms eight, beset with numerous warts or suckers, and in most species two pedunculated tenta- cula; head short; eyes large; mouth resembling a Parrot’s beak, It is upon the exclusive shape of the shell, and not the animal inhabitant, that the Linnean arrangement of Conchology is formed. In early periods, naturalists were in much doubt whether to found their Conchological arrangements on the animal, or the shells ; and at last it was determined, that it should be the latter ; because few of the marine shells that were then found had the animal in them, prior to the time when dredging was resorted to. The greater part of shells in many coilections at the present day, have been found upon the beach, divested of their animal, having been cast ashore by the agitation of the sea in storms ; and the inhabitant decayed before they were picked up. Many shells are very different in their young and adult state both in form and colour ; the student ought, therefore, to make himself well acquainted with the generic characters, to enable him to discriminate the difference. But, indeed, this is often a difficult matter, even to those who have studied the science for many years. In almost all the Cypreze, there is considerable difficulty in dis- tinguishing them from the Volutez and Bulle, in their young state; EXPLANATION OF THE PARTS OF SHELLS, 15 the denticulated lip being the last part of the shell which the animal forms. The Strombus genus wants the expanded lip in the young shell, from which circumstance it is frequently taken for aspecies of the Buccinum and Murex. The Linnean arrangement of shells consists of three orders, viz. Multivalve, Bivalve, and Univalve. The first order, Multivalve, is made up of shells consisting of more parts than two. Every part of a shell which is connected by a cartilage, ligament, binge, or tooth, is called a valve of such shell. The second order, Bivalve, is made up of shells having two parts or valves, generally connected by a cartilage ; for example, the Cockle and Muscle. The third order, Univalve, is made up of shells complete in one piece; for example, the Periwinkle and the Whelk. This order is sub-divided : first, into shells with a regular spire, and those without a spire. The first order consists of three genera: Chiton, Lepas, and Pholas. The second order contains fourteen genera: Mya, Solen, Tel- lina, Cardium, Mactra, Donax, Venus, Spondylus, Chama, Arca, Ostrea, Anomia, Mytilus, Pinna. In the third order there are nineteen genera: Argonauta, Nautilus, Conus, Cyprzea, Bulla, Voluta, Buccinum, Strombus, Murex, Trochus, Turbo, Helix, Nerita, Haliotis, Patella, Den- talium, Serpula, Teredo, and Sabella. It will now be proper, before proceeding to a description of the generic characters of the Linnean system, to make the student acquainted with the terms used in Testaceology, as far as regards the different parts of shells. EXPLANATION OF THE PARTS OF SHELLS. MULTIVALVE. VaLves or Currons.—Chitons in general have eight trans- verse, broad, but very short valves, placed on the back of the B2 16 INTRODUCTORY. animal, and inserted at their sides into a marginal tough liga- ment. Plate I. fig. 1, AA A. Operculum consists of four small valves on the summit of the cepas, which shut up the superior orifice ; it is in a certain degree stationary, and different from the operculum of univalve shells, which will hereafter be described. Plate I. fig. 1. a. Fig. 9. re- presents a profile view of the operculum removed from its place, A the front valves, Bthe back valves. Fig. 10. a front view of the operculum. Base, is that part of the shell by which it is fixed to rocks and other bodies. Plate I. fig. 1. and 2. 8B B B.—H isa piece of stone to which the base is fixed, and G a piece of wood to which the shells of this section are generally attached. Ligament, is the membranous or tendinous substance by which the valves or parts of the shell are attached. Some multivalve shells are connected, by the parts of one valve locking into an- other. Plate IJ. fig. 2. pp p. The ligaments vary considerably in their texture, being scaly, prickly, smooth, or punctated Ridges, are certain convexities in many of the Lepas tribe, sometimes longitudinal and sometimes transverse. Plate I. fig. deer. Peduncle. A sort of stem by which the shells of the second division of Lepas are attached to wood, &c. Jt is a mem- branaceous substance, similar to a bladder but materially - thinner, and filled with a liquid which evidently affords nourish. ment to the animal. Plate I. fig. 2. cc. the peduncle is usually affixed to a piece of wood as represented at G. Feelers, are those crenated arms, evolved from the side of the Lepas anatifera, and other shells of the second division of Lepas. While the animal is in the water it continually moves its feelers, evidently for the purpose of entangling minute marine insects, as food. Plate I. fig. 2. ££. Accessory Valves, are small plates which cover the apex at the hinge of the Pholades, or are situated below the hinge. Plate Mkip.. 3. Ac ' Margin.—A fleshy border in which the valves are attached in the genus Chiton. Plate I. fig. ll. B B. EXPLANATION OF THE FARTS OF SHELLS. L7 BIVALVE. Bivalve shells consist of two parts or valves, connected by a cartilage, and a hinge which is generally composed of teeth, those of the one valve locking into a cavity in the other. The valves of some bivalve shells are formed exactly alike, and others are very different ; the one being smooth, the other rugose 3 one flat, and another convex ; and often one is shorter than the other. The shells of the Mya, Solen, Tellina, Venus, and others, have in general both valves alike, while those of the Spondylus, Ostrea, Anomia, and Pinna, have in general dissimilar valves. The first of these kinds are called equivalve, and the latter inequivalve. Equilateral shells, are those whose sides are alike, as in the shells of the genus Pecten, commonly termed Scallop shells in England, or those shells worn by pilgrims in former times ; “¢ And fix’d the Scallop on his hat before.’’ PARNELL. Plate II. fig. 2. and plate VII. fig. 14. This is also exempli- fied in the Pectunculus. Inequilateral valves, are shells whose sides are unequal ; and of different shapes, as in the Mactra, Donax, &c. Summit, is the most elevated point of that part of the shell in which the hinge is placed. Plate I. fig. 4. and 8. aa. In naming this the summit, we do not follow the axiom of Linneus, but because we consider it more properly the summit of the shell, than the opposite extremity. Base, is the reverse of the above, or that part of the shell immediately opposite the summit. Plate I. fig. 6. and 7. dd. Sides, the right and left parts of the valves. Plate I. fig. 6. c. Anterior slope, is that part of the shell in which the ligament is situated. In viewing the anterior slope in front, the beaks of the shell retire from view. Plate I. fig. 4. 2. Posterior slope, that part of the shell opposite the anterior slope ; in viewing it in front, the beaks point to the observer. Piate J. fig. 4. h. Disk, the convex centre of a valve, or most prominent part of BO 18 INTRODUCTORY, the valve, suppose it with its inside lying undermost. Plate I. fig. 4. o. Inside, the concave part of a valve. Plate IV. fig. 6. n. Cicatriz or Tongue, is the impression left on the inside of the valves, by the adhering muscles of the animal. It differs in most shells, according to the shape of the muscle, as semi-ovate, round, lunate, elongated, &c. As a specific distinction, it is often of great use; being, with a very few exceptions, alike in shells of the same species. Some shells have only one cicatrix, as the Edible Oyster, and Muscle ; others have two, and some few more; the Tellina Fausta for example. Plate I. fig. 6. and8. eeee Lunule. The lunated depressions, situated in the anterior and posterior slopes. In different species of Venus they are prominent, characteristic marks, often of much service in ascer- taining a species. Plate I. fig. 4. bb. Ligament perforation. ‘The circular aperture, or perforation, through which the ligament passes ; by which the animal of the Anomia attaches itself to stones, and other marine extraneous bodies ; it is in general situated in the flat valve, though there are a few exceptions to the contrary. Plate I. fig. 7. m. Hinge, is the point at which bivalve shells are united, it is formed by the teeth of one valve inserting themselves between those of the other, or by the teeth of one valve fitting into the cavities or sockets of the opposite one. It is on the peculiar construction of the hinge that the generic character of bivalve shells is principally founded, together with the general contour of the shell. Plate II. fig. 1. and 8. q q q. Teeth of the Hinge. Upon the number and relative situation of the teeth, principally depend the specific distinctions; they are of various forms, and very differently placed ; some are single and large, others numerous and small, orbicular, spatuliform, la- , minated, &c. Some hinges have no visible teeth, and are termed inarticulate. — When a primary tooth has a groove or hollow in its centre, it is called complicated. Plate IV. Fig. 6. e; those with few teeth are termed articulate. Plate IV. fig. 1. and 12. and those with many teeth multiarticulate. Plate 1V. fig. 2. 3. 4, &e. Plate I. fig. 6. andS. 9999. Primary Teeth, are those teeth in general situated in the cen- tre of the hinge, and are for the most part broad, large, and dis- EXPLANATION OF THE PARTS OF SHELLS. 19 tinct, often elevated ; and in general are inserted in a cavity in the opposite valve. They however differ very much in some shells, but may easily be distinguished. Plate IV. fig. 1, 3, and7.aaaaa. These are also termed the Cardinal Teeth. Lateral Teeth, Plate IV. fig. 10. are teeth which diverge from the umbo, and are in general long and flat, often doubie and di- vided by a groove or hollow. Plate IV. fig. 2, 4,6. and 7, bbbb. Double Teeth, Plate IV. fig. 1. ce. Incurved Teeth are those which are bent round, as in the sin- gle tooth of the Solen Siliqua. Plate IV. fig. 8 ff Recurved Teeth, are those which are bent backwards, as in the hinge of the Panopea. Plate XVIII. fig. 9; and Spondylus, Plate II. fig. 8. f/f Middle Teeth, Plate IV. fig. 4. d d. These are also termed Cardinal Teeth. Numerous Teeth, are those small upright teeth, set in rows, of which the hinges of all the species of the genus Arca are formed. Plate IV. fig. 10. & &. Cavity of the Hinge. The hollow depression in which the li- gament of the Ostrea is situated, generally of a triangular form. Plate IV. fig. 11. g. Ligament of the Hinge, or cartilage, is that flexible fibrous substance by which the valves are united, and the hinges kept in their proper places ; always situated under the beaks of the Shell. Plate II. fig. 1, 3. and 4.717; Plate LV. fig. 3. n. Beak is the extreme point of the summit of bivalves, which in many species turns spirally downwards, or to the one side, as in most species of Venus, &c. From this circumstance it is sel- dom the highest part of the shell. Plate II. fig. 5. rr. Seam. When the valves are closed, the line of separation be- tween them is so called. Plate II. fig. 6. ¢ ¢. Umbo. ‘That part situated immediately under the beak. Plate I, fig. 6. w; and Plate II. fig. 4. w. Ears. The processes on each side of the beak, in most spe- cies of that division of Ostrea, called scallops; some have one ear very large, and the other small; and some are scarcely observable on one side. Plate If. fig. 2h h. Superior Ear. Plate IV. fig. 11. A. Inferior Ear. Do. doy & 20 INTRODUCTORY. Margin. The extreme edge of the whole shell, or the circum- ference of either valve, all round. Plate I. fig. 4. p; and Plate 2. fig. 1. p. Crenulated margin. That fine notched edge of most of the cockles, which unite into notches in the opposite valve. It is by no means uncommon in other shells, particularly those of the genus Donax. Plate IV. fig. 6. mm. Strie are fine thread-like lines, generally on the exterior sur-. face of shells, and are sometimes both longitudinal and trans- verse. When the striez of shells appear indistinct, as if worn out, it is termed obsolete strie. In some instances the insides of shells are striated ; for example, the Murex tulipa. ( Fasciolaria tulipa, Lamarck.) The character of the striz is often of much use in distinguishing species. Plate II. fig. 2 Right Valve is that valve which, when viewed with the inside uppermost has the anterior slope pointing to the right hand. Plate I. fig. 8; and plate 4. fig. 5. and 6. 6. Left Valve. The opposite of the above; the anterior slope points to the left hand, when viewed from the inside. Plate DV tign3; 6,:7, 9: ike. Length of the Shell is taken from the ligament, or the beak, to the opposite margin. For example, the common muscle: it is longer than it is broad, and the solens are broader than long. Plate I. fig. 5. uu. and Plate 2. fig. 4. uu. Breadth is measured from the most extreme edge of the an- terior and posterior slopes, being in a contrary direction from its length. Many shells are broader than long, such as most of the Mya, Solenz, Tellinz, &c. ; and the Mytilus, Ostrea, Pin. na, &c. are in general longer than broad. Plate I. fig. 5. vv. Plate II. fig. 4.0 v. Byssus or beard, is an appendage composed of filaments of a silky texture, by which some of the Bivalves fasten themselves, to their beds, such as the Muscles, Pinne, &c. Plate II. fig. 6. s. EXPLANATION OF THE PARTS OF SHELLS. 21 DESCRIPTION OF PLATE IY. HINGES OF THE LINNEAN GENERA OF BIVALVES. Fig. 1. Hinge of the Mya pictorum. (Unio pictorum, La- marck.) a. Primary tooth, ¢ c. double teeth. Fig. 2. Hinge of the Solen siliqua. 6. Lateral teeth. Fig. 3. Hinge of the Telhna radula. (Lucina radula, La- marck.) aa. Primary teeth, n. cartilage. Fig. 4. Hinge of the Cardium aculeatum. 6. Lateral tooth, d d. middle teeth, / /. spines. Fig. 5. Hinge of Mactra hians. (Lutraria hians, Lamarck.) Fig. 6. Inside of both valves of the Donaz trunculus. A is the left valve, and B is the right valve, b. lateral teeth, 6. primary complicated tooth, or cleft in the middle, mm. crenulated margin. Fig. 7. Hinge of Venus gallina. (Ortygia gallina, Leach.) aa, Primary teeth, b lateral tooth. Fig. 8. Hinge of Spondylus gederopus, f f. incurved teeth. Fig. 9. Hinge of Chama Cor. (Isocardia Cor, Lamarck.) Fig. 10. Hinge of Arca piiosa. (Pectunculus pilosus, La- marck.) & k, numerous small teeth ; the distinguishing charac- teristic of the genus Arca. Fig. 11. Hinge of Ostrea varia. (Pecten varius, Lamarck.) g. cavity of the hinge, 4. superior ear, 2. inferior ear. Fig. 12. Hinge of Anomia Ephippium. UNIVALVE. The shells composing this order are far more numerous than the two preceding, both in genera and species ; and it requires a considerable degree of attention, to discriminate many of the spe- cies, as they run into each other so much; and they are divested of the strong and distinct character afforded by the teeth of bi- _valves ; besides many of the species there are several varieties, ' In the examination of shells of this order, the general contour or Gutline of the whole shell, is the first particular to be attended to, as this leads to those distinctions necessary in the definition of simple, spiral, or turbinated shells, or, more strictly according to the Linnean method of discrimination, Univalves with a re- gular spire, and those without a regular spire. The genera of this 22 INTRODUCTORY. order are formed principally from the shape of the aperture, ta- ken in conjunction with the general shape of the shell; from the spire being lengthened or depressed, being with or without a ranal, the length of the beak and its direction, together with the particular form of the outer lip: the colour of shells only serves as a specific distinction, and cannot in this respect, in all cases, be depended upon, although in others it is an unvarying test. The particular manner in which the spots are disposed, frequently characterises species. Apex. The summit, tip or highest part of the spire. Plate Leis. 82879) A AAL Base is the opposite extremity from the apex, or tip of the spire. In shells with a beak or rostrum, it implies the tip of such beak; Plate II. fig. 11. B. In shells without a beak it is understood to be the lower part, as before-mentioned, opposite the apex; Plate II. fig. 8. and 9. B B. In the Patella and some others, the base of the shell is that part on which it rests when it is laid on its mouth. In the Dentalium and Teredo it is the wider end. Body of the shell is the first or lower whorl of the spire, in which the aperture is situated, and is in general longer than the remaining whorls. Plate II. fig. 10 and 12. FF. and Plate HI. fig. 7 and 9. FF. Froné of the shell, is that side where the aperture is situated. Plate II. fig. 7. 2; and Plate III. fig. 8. J. Back is the opposite side to that in which the aperture is pla- ced or turned directly from the observer. Plate III. fig. 5 and 10. GG. The venter or belly, is the most prominent part of the lower whorl or body, generally situated in the vicinity of the lip over, the aperture ; and formed by the convexity of the aperture. It is in general only made use of in describing shells, whose body is large in proportion to the size of the spire. Plate III. fig. 5 and 10. H H. Sides. The extreme edges of the shell, when viewed either in front or from the back. Plate II. fig. LL. KA KKKKAK KA, Right side is, when the shell is viewed in front, that side next the observer’s left hand. Left side, the side with the aperture in it. Aperture, or mouth, is that part of the lower whorl or bolt, EXPLANATION OF THE PARTS OF SHELLS. 23 by which the animal protrudes itself. This is one of the princi- pal generic distinctions of Univalve shells, and differs very much in shape ; some apertures. being rounded, others semilunar, an- gular, &c. Plate II. fig. 9. and 11.C Cyand Plate III. fig. 1, 3, and 14.C C C. Some apertures have a canal at their base, and others are devoid of it. In various genera it extends the whole length of the shell, as in the Cypraa, and some of the Cones with depressed spires. This in several individuals is either entirely open, or is closed by an operculum or lid, which is usually affixed to the foot of the animal. Canal or gutter, is the inside of the elongations of the aper- ture, or both lips of the shell of those species with a beak, in which it forms a concave channel or gutter, running from its commencement in the aperture, to the extremity cr base, Plate II. fig. 10, and 11. Q Q. Plate III. fig. 8. @. Some species are furnished with two canals, one situated at the junction of the outer lip and body, as in the Murex lampas, &c. Beak, or rostrum, is that lengthened process in which the ca- nal is situate ; it commences a little higher up, on the outside, than the insertion of the canal in the inside, which is always dis- tinctly marked by the line of the aperture. Plate IJ. fig. 11. p. This process is not so conspicuous in some of the species of Vol- uta, but is more marked in the genera Murex, Fusus, Pyrula, &e. Pillar, or columella, is that process which runs through the centre of the shell in the inside, from the base to the apex in most univalve shells, and appears to be the support of the spire ; and, indeed, seems to form that part of the shell; it is in gene. ral grooved or folded; but, as it is situated in the interior of the shell, 4 minute description is unnecessary. Plate II. fig. JO and 12, MMMM M.; and plate III. fig. 9, 4 MM. The internal edge of its base is frequently described as having plaits &e. Plaited Columella are those folds, or plaits, which are the dis- tinguishing characteristic of the Volute and other genera. Plate II. fig. 7, z. Pillar Lip is a continuation of the glossy process with which the aperture is lined, and expanded on the columella. Plate III. figures 7 and 8, O O. This is termed the inner lip by some authors. 24. INTRODUCTORY. Outer Lip. The expansion, or continuation of the body of the shell, on the left margin of the aperture, and is also lined with the glossy process of the aperture. Plate II. fig. 7, NV; and plate III. fig. 8, VV WV. The latter is an example of the alated or winged shells. Operculum, or lid. This is only an appendage to the turbinat- ed or spiral shells affixed to the foot of the animal, sometimes of a testaceous, in others of a horny or cartilaginous substance. It acts as a door or lid, and is calculated for the protection of the animal, when it retires within its dwelling, from the intrusion of its enemies, and adapted to the shape of the aperture, w'iich it closes nicely up: as exemplified in the cartilaginous opercu- ium of the common Periwinkle, (the Turbo Littoralis of Linné,) ‘it is of a brown horny appearance; and is also to be found in the large Whelk, which is common in our seas, and sold in fish- markets as food. Plate III. fig. 4. kf Spire consists of all the whorls of the shell, except the lower one, which, as before observed, is termed the body of the shell. Plate Il. fig. 12,D; and plate III. figures 7 and 8, D D. This spire is a prominent feature of the Univalve; and upon its being elevated, depressed, &c. depends much of the generic and specific definition. Adanson, in his ‘ Natural History of Senegal,’ printed at Paris in 1757, says that the external charac- ter of the spire varies according to the plane they turn upon, which, he observes, is either horizontal, cylindrical, conic, or ovoid. At the same time, he admits that there are a great many intermediate forms, which cannot properly be defined. It is a remarkable circumstance, that many of the young shells have not the same number of wreaths as the adults; from which it would appear, that the part of the animal nearest the apex, never increases in size. The number of wreaths cannot, at all times, be depended upon. A full grown shell may, how- ever, be known from the outer-lip, which has generally an un- finished appearance in young shells. Indeed, in all the land and fresh water shells, it isa distinct criterion, as they are never com- plete in the form of the outer-lip, till full grown. Whorl is one of the wreaths or volutions of the shell. Plate II. fig. 8, ; and plate III. fig. 10, L. Depressed Spire is when the spire is very flat, as in the shells of the genus Planorbis,&c. PI. II. fig. 12, d; and pl. III. fig. 5, s. EXPLANATION OF THE PARTS OF SHELLS, 25 A flat shell is figured in plate III. fig. £4. Involuted Spire, those shells which have their whorls, or wreaths, concealed in the inside of the first whorl or body, as in some of the Nautili and Cyprwe. Plate III. fig. 3,¢; plate VII. fig. 19; and plate VIII. fig. 21. Suture of the Spire, or whorls, is a fine spiral line, which separates the wreaths or whorls from each other ; it is some- times crenulated, undulated, or suleated, and not unfrequently elevated or projecting. Plate Il. ee. Reversed, or Heterostrophe Spire, is when the volutions of the spire revolve in the same manner as a common corkscrew, or when the aperture is placed downwards, the nature of the spire runs upwards from the right hand te the left, plate III. fig..413. In some of the more depressed species of Helix, or Nautilus, great attention is requisite in order to ascertain which is really the upper side of the shell, for it is on that side the spiral turns are to be taken from the centre or apex; and, in most instances, this is to be determined by the oblique direction of the aperture to the under part, where the lip rarely extends so far as on the upper part. In fixed shells, such as Serpulz, there is no difli- culty, as the side which is sessile must be considered as the base, or under part. Thus in the Serpula Lucida the fixed part is sometimes very small, and the mouth protends spirally upwards, in a contrary direction to the sun; and therefore must be con- sidered a reversed or heterostrophe shell, the same as if the vo- lutions nearest the mouth had turned laterally upon the centre or fixed ones. ‘This shell, indeed, is most frequently found with regular lateral volutions; and though subject to great variety, with respect to contortions, it invariably turns the aperture one way. In some species of Nautilus, however, there can be no rule to ascertain whether the shells are dextral or sinistral ; for when the aperture is exactly central, the lip embraces the body equally, and the sides of the shell are similar, as in the Nautilus Calcar, which cannot be defined. In others of that genus, asin N. Bec- cariiand Beccarii perversus, two shells, the principal distinction of which is the contrary turn of their volutions, it is easily determined by the convexity of the upper side, and, of course, the aperture being placed somewhat beneath. c 26 INTRODUCTORY, Chambers are the cavities divided by partitions, at regular or irregular intervals ; as in the Nautilus. Plate III. fig. 11, ww ww WwW. In some of the Serpula there are also divisions, but they are not regular as in the Nautili ; and besides, they differ from them in being devoid of a siphunculus or communication between the chambers ; the animal forms a complete partition and adds to its shell, which it would appear to be necessitated to do, from its body growing too large for its abode. Several of the Patelle have chambers formed of laminous partitions, subspiral cells, or processes ; these in general lie hor- izontally, and are quite open at one end, as in the Patella testu- dinaria, &c. of Linnzus, and the prickly Crepidula, and Chinese Calyptrea, plate XIV. fig. 16 and 19; and plate III. fig. 6, w., or funnel shaped, as in the Sypho striatus. Plate XIV. fig. 21. Umbilicus is in general a circular perforation in the base of the lower whorl, or body, of many univalve shells. ‘This is com- mon to most of the Trochi, in some species of which it pene- trates from the base to the apex; widest at the base, and gradu- ally tapering to the top. Plate III. fig. 1. wu. Sub-umbilicated shells, are those which have the umbilicus covered in a greater or less degree by a thin process; which, in some, almost entirely closes the opening or mouth. This cha- racter is most commonly to be met with among species of Bucci- num and Murex. Shells which have no umbilicus are termed imperforate. Stphunculus is that small round perforation which forms a communication between the chambers of the Nautili, and pene- trates through the whole spire of the shell. Plate III. fig. 11. v. Varices are transverse ribs which cross the whorls of shells in some species of Buccinum, Murex, and Tritonia, and exempli- fied in the Cassis areola) Plate XI. fig. 21. Warices are formed by the periodical growth of the shells, these being the margin of the outer lip, to which the animal has attached its periodical enlargements. In some species they have more the form of sutures than ribs; this is owing to the margin of the outer lip being but slightly developed. Ribs are those longitudinal and transverse protuberances which are in many of the univalye shells. Plate III. fig. 12. rrvr. EXPLANATION OF THE PARTS OF SHELLS. 27 Teeth of univalves, according to Colonel Montagu, are not properly denticles, or tooth-shaped protuberances, but are fine white laminz, or ridges, running spirally backwards, in a parallel direction to each other; those on the exterior lip may, in most instances, be traced through the outside of the shell, and are nearly alike in length. Plate III. fig. 13. a. Epidermis is a skin, or cuticle, covering the exterior surface of many shells of all the orders, destined by nature to protect their surface from being injured. It is membranaceous, somewhat similar to the periosteum, which covers the bones of animals. This substance is the production of the animal inhabiting the shell; it is uniformly observed in some species, and not at all in others. Shells with a rugged or uneven surface have almost always this epidermis. In some it is strong, laminated, velvety, fibrous or rough, often beset with long hairs, and in others very thin, smooth and peilucid, and admits the colours of the shell to shine through it. In some species it is so dusky, that it entirely obscures the beautiful colouring of the shell beneath. Although many shells are very beautiful, even with this cuticle on them, they are much more so when it is removed ; but I would by no means advise the collector of shells to remove it, unless he may have several duplicates of the same species; and then he may do it by way of variety. It is always preferable, however, to keep them in a state of nature. A shell with epidermis is represented in Plate III. X; and the effect of the epidermis removed at J, All other protuberances, furrows, &c. will be described at the end of the work, in the Glossary of Terms used in the Science. The next thing to be taken into consideration, is the Linnean genera composing the three orders of shells. OF THE LINNEAN GENERA. ORDER FIRST. MULTIVALVE SHELLS. Animals soft, of a simple structure, and covered with a eal- careous habitation or shell. Genus 1.—CHITON. Animal a Doris; shell consisting of several segments or valves, placed transversely on the back of the animal, and lying upon each other at their anterior edge. Chiton marginatus.—THE MarcinaTEp Curton. Plate V. fig. 1. With eight carinated valves, projecting over each other in the form of a beak ; very finely shagreened, and having a broad margin, of a dusky or ash coloured brown; 3ths of an inch long. JInhabits the British seas, under stones. The animals of this genus are marine, adhering to rocks and stones, in genera] near low water mark, and are, at first view, very like an Oniscus Genus 2.—LEPAS. Animal a Triton; shell affixed at the base, and consisting of many unequal erect valves. Lepasrugosa.—THE Rovucu Lepas. Plate I. fig. 1. (Bal- anus rugosus, Lamarck.) With a sub-cylindric shell, having usually six furrows, which frequently widen towards the top, and terminate in angulated points, sometimes as wide as at the base ; compartments sulcated, often striated longitudinally; of a yel- lowish colour; operculum consisting of four rough, angulated, erect valves. Lepas tintinnabulum—Tue Lirrte Beit Lepas. Plate V. fig. 2, (Balanus tintinnabulum, Lamarck.) Shell conical, with MULTIVALVE SHELLS. 29 the valves strongly and irregularly ribbed, interstices delicately striated transversely ; colour purple, inhabits the West Indies. These are termed acorn shells in Britain. This genus consists of two families or divisions, very different in their shape. The first of which is the Balani, or Acorn shells, of a subconie form, with an operculum or lid, consisting of either four or six valves. The body of the shell has six valves. The second family is the Anatiferous, which are connected to, and sup- ported at the base by a tendinous tube or pedicle, ofa flexible nature, allow- ing the animal to writhe about in quest of food ; it has no operculum, is wedge-shaped, and consists of five or more unequal valves. Lepas anatifera.—TueE Goose Lerpas. Plate I. fig. 2. (Ana- tifa levis, Lamarck.) Shell compressed, with five obsoletely striated valves ; the lower valves somewhat triangular; the su- perior ones long, and tapering to an obtuse point; connected by an orange-coloured cartilage ; base affixed to a peduncle of a co- lour between vermilion and orange. This shell generally adheres to pieces of rotten wood or the bottoms of vessels, and is found in almost all seas. Linneas founded the name of this shell on the circumstance that if was from it that the Barnacle Goose was supposed to have had its origin. Ger- ard’s account of this transformation, as it affords a remarkable instance of the credulity of the times, is too curious to be omitted. ‘There are found in the north parts of Scotland, and the islands adjacent called Orchades, cer- tain trees whereon do grow certain shells tending to russet, wherein are contained little living creatures, which shells in time of maturitie do open, and out of them grow those little living things, which falling into the water do become fowles, which we call Barnacles ; in the north of England Brant Geese ; aud in Lancashire, Tree Geese ; but the others that do fall up- on the land perish and come to nothing. Thus much from the writings of others, and also from the mouths of people of those parts, which may very well accord with truth. **But what our eyes have seene and hands have touched we shall declare. There is asmall island in Lancashire called the Hill of Flounders, wherein are found in the broken pieces of old ships, some whereof have been cast thither by shipracke, and also the trunks and bodies with the branches of old and rotten trees, cast up there likewise: whereon is found a certain spume or froth that in time breedith into certain shells, in shape like those of the Muskle, but sharper pointed, and of a whitish colour, wherein is con- tained a thing in form like a lace of silk, finely woven as it were, together, of a whitish colour, one end whereof is fastened into the inside of the shell, even as the fish of Oysters and Muskles are ; the other end is made fast un. to the belly, of a rude mass or lumpe, which in time commeth to the shape and form of a bird ; when it is perfectly formed the shell gapeth open, and the first thing that appeareth is the foresaid lace or string ; next ‘comes the legs of the bird hanging out, and as it groweth greater it openeth the shell by degrees, till at length it is all come forth, and hangeth only by the bill; in short space often it cometh to full maturitie, and falleth into the sea, where it gathereth feathers, and groweth to a fowl bigger than a Millard, and lesser than a Goose, having black legs, bill or beake, and feathers black 30 LINNEAN GENERA. and white, spotted in such a manner as is our Magpie, called insome places a Pie-annet, which the people of Lancashire call by no other name than a Tree Goose; which place aforesaid, and those parts adjoining, doso much abound therewith, that one of the best is bought for three pence. For the truth hereof, if any doubt, let them repaire unto me, and J shali satisfy them by the testimonie of good witnesses.” Gerard’s Herbal, p. 1558. ‘The shells of this genus adhere in clusters to rocks, shells, floating wood, and other extraneous marine substances, and being incapable of changing place, are supposed to be true hermaphrodites. Genus 3.—PHOLAS. Animalan Ascidea ; shell bivalve, divaricate, with several les- ser, differently shaped, accessary ones, at the hinge ; hinges re- curved, united by a cartilage ; in the inside, beneath the hinge, is an incurved projecting tooth. Pholas crispata.—Tue Cwurtep Puoras. Plate V. fig. 3. Shell oval, gibbous, pale ochreous-yellow; part next the hinge obtuse, gaping at both ends; a longitudinal furrow near the centre of each valve; one half covered with muricated waved striz and wrinkles, the other substriated. 2 inches long, and 3 broad. Inhabits the British coasts. Pholades are found below high water-mark, burrowed in hard clay, lime- stone, and wood, which they perforate in their younger state, and as they increase in size enlarge their habitation. The phosphorescent property of the Pholades is very remarkable. They contain a liquor which shines with uncommon splendour in the dark, and il- luminates whatever it touches, or happens to fall upon. * “There is,’? says Dr Priestly, “‘a remarkable shell-fish called Pholes, which forms for itself holes in different kinds of stone. This fi~h illuminates the mouth of the person who eats it; and it is remarked, that contrary to the nature of other fish, which give light when they tend to putrescence, this is more luminous the fresher it is ; and when dried, its light will revive on being moistened either with salt water or fresh ; brandy however imme- diately extinguishes it.” + It is to be regretted, that the experiments made by chemists on those ani« mals, which have a luminous appearance in the dark, have not been suf." ficiently decisive, to enable us to state the true cause of it; but there is every reason to believe that it proceeds from phosphorus, which is abun- dant in all animal bodies. * Seo Memoirs of the French Academy, 1712. + Priestly’s Optics, page 403. BIVALVE SHELLS. Sl ORDER SECOND, BIVALVE SHELLS. Genus 4.—MY A, Animal an Ascidia ; shell bivalve, generally gaping at one end ; ‘hinge with a broad, thick, strong, patulous tooth, seldom more than one, and not inserted in the opposite valve. Mya Arenaria.—Tue Sanp Mya. Plate V. fig. 4. Trans- versely ovate, rounded behind ; tooth very broad, thick, obtuse, projecting and erect ; with a small lateral tooth. _The Myz are to be found both in the sea and in rivers. The marine kinds generally live under sand or sludge, and the place where they lie is betrayed by a small hole, out of which they occasionally protrude their proboscis. Those which inhabit rivers, are generally found in the mud at its bottom. In some places the animals are used for food ; but what makes them of con- siderable importance is, the quantity of pearls which they sometimes pro- duce. As illustrative of the value of pearls produced by the Mya Margariti- fera, (Unio Margaritifera, Lamarck) it may be mentioned that according to Camden, Sir John Hawkins had a patent for fishing that shell in the river Irt in Cumberland. This shell is well known in Britain, by the name of the Pearl Muscle. We are informed in the philosophical transactions, that se- veral pearls of great size have been procured from the rivers in the counties of Tyrone and Donegalin Ireland. One of them weighed 36 carats, and would have been worth £40, but owing to its being impure, it lost much of its value. Other pearls from the same places have sold from £4 10s., to £10 each. One of the latter price was sold a second time to Lady Genlealy, who had it placed in a necklace, and refused £80 for it, which she was of- fered by the Countess of Ormond. ‘There was also a great fishery for pearls in the river Tay, which extended from Perth to Loch Tay ; and it is said that the pearls sent from thence, from the year 1761 to 1764, were worth £10,000, It is not uncommon in the present day, to find pearls in those shells, which bring from £1 to £2. It is said that those in the Scottish Crown which forms part of the regalia now exhibited in the Castle of Edin. burgh, are the produce of the river Tay. Genus 5.—SOLEN. Animal an Ascidia; shell bivalve, oblong, open at both ends; hinge with a subulate reflected tooth, often double, and not in- serted in the opposité vacve. Solen Siliqua.—Tue Pop Soten, Plate I. fig. 5. Shell linear, straight ; in one valve two teeth, and one in the other, having a iateral inclined tooth corresponding with the opposite lamina ; covered by a fine olivaceous brown epidermis, very glossy, and 32 LINNEAN GENERA. transversely striated, taking a longitudinal direction across the shell. One inch long, and from seven to eight broad. Com- mon on most sandy shores of Europe. wu Length of the shell, » v breadth of the shell. Solen Ensis.—TuHE SaBRE SoLen. Plate VY. fig. 5. Linear, a little bent like a sabre ; with a single tooth and lateral lamina, in one valve, locking into two teeth, and double lamine in the other ; covered with a fine olivaceous, glossy epidermis ; one inca long, and from five to seven broad. Inhabits the coasts of Eu- rope. Solen Antiquatus.—Tur ANTIQUATED SoLEeN. Plate IT. fig. 1. Shell thin, white, and subpellucid ; moderately glossy, with concentric striz#; ends rounded and gaping: hinge near the centre, furnished with a single tooth in one valve locking in be- tween two in the opposite, the teeth are erect, oblique, and stand beyond the margin; outside covered with an umber-coloured epidermis. Found on the Cornwall and Dorsetshire ceasts. i The cartilage, ~ inside, p margin or limb, g hinge. The Solens inhabit the ocean ; they are generally found buried about six inches deep in the sand, into which they penetrate with great facility ; their residence is known by a small dimple on the surface. In some places they are used as food. \ Genus 6.—TELLINA. Animal a Tethys; shell bivalve, generally sloping on one side ; in the fore-part of one valve a convex, of the other a con- cave fold; hinge with usually three teeth, the lateral ones smooth in one side. There are three families of the Tellinz : ovate and thickish,* ovate and compressed,** suborbicular. * ** Tellina fabula.—Tue Fatse Tetra. Shell very thin, pellucid and oval, generally of a dull yellow, and darker towards - the umbo; which is nearly central, pointed, and turned a little to one side; the anterior side slopes to an obtuse point; the posterior side is large and rounded ; hinge furnished with three teeth in one valve and two in the other. l Cartilage, g g hinge. Tellina Donacina.—TuEe Donax-Like TEeLuina- Plate V. fig. 6. Suboval, flattish, much sloping on the anterior side, semi- striated, and semi-pellucid, hinge with two teeth in one valve, and one in the other, pale yellow; longitudinally radiated with BIVALVE SHELLS. oe pink ; half an inch long and three fourths of an inch broad. In- habits the coasts of Britain. The Tellin inhabit the ocean, rivers and lakes. Those of the ocean lie buried in the sludge, near the shore, and make two apertures in the sand ; when the tide has receded, they may be easily found by looking for these marks. Genus 7-—CARDIUM. Animal a Tethys; shell bivalve, nearly equilateral, equivalve, generally convex, longitudinally ribbed, striate or grooved, the margin dentated ; hinge with two alternate teeth in the middle, near the beak; one of them commonly incurved; and larger remote lateral teeth on one side, each locking into hollows in the opposite valve Cardium edule.—YTue Eprste Carpium. Plate V. fig. 7. With about twenty-six, antiquated longitudinal ribs ; of a cream yellow colour; the posterior end a little elongated. Usual diameter one inch; but they are found in Orkney two and a half inches in breadth, and two and a-fourthin length; in which case the posterior extremity is considerably produced. When young the cockle is nearly orbicular, and pure white. The cockles, with the exception of one species, inhabit the ocean only ; they, in general, burrow just under the surface of the sand, barely covered, to which.they are necessitated from the shortness of their tube, by which they draw in and throw out the water. They are used as a wholesome and nourishing food ; and abound in most sandy shores. Genus 8.—MACTRA. Animal a Tethys; shell bivalve, with unequal sides, equivalve ; middle tooth of the hinge complicated, with a small hollow on each side, lateral teeth remote, and inserted into each other. Mactra Lutraria.—TuE mup Mactra. (Lutraria elliptica, Lamarck.) Plate VI. fig. 8. Transverse oblong-oval, smooth, with irregular concentric stri#, and an olive, or yellowish epidermis, glossy white within ; gaping at bothends. Two and a-half inches long, and from four to six broad. Inhabits the British coasts. Shells of this genus inhabit the ocean only. These lurk in the sand or sludge, most commonly at the mouths of rivers, or near them, 34 LINNEAN GENERA. Genus 9.—DONAX. Animal a Tethys; ‘shell bivalve, with generally a crenulate margin, the frontal margin very obtuse ; hinge with two teeth, and a single marginal one placed a little behind, rarely double, triple or none. Donazx trunculus.—Tue Truncated Donax. Plate IV. fig. 6. and plate VI. fig. 9. Transverse, oblong, glossy, finely striated longitudinally, and transversely banded and radiated with purple ; white, clouded with purple within; internal margin crenulated. Inhabits the British coasts. The shells of this genus are transverse, triangular, inequilateral, flattened, truncated before, and wedge-shaped. They inhabit the ocean; lurking in the sand of the shore, and may be found on the reflux of the tide. Genus 10.—VENUS. Animal a Tethys ; shell bivalve, the frontal margin flattened, with incumbent lips; hinge with three teeth, all of them ap- proximate, the lateral ones divergent at the tip. This genus is divided into two sections: pubentes * and impubentes.** This latter section is sub-divided into three families: sub-cordate,f orbicu- lar,++ and oval.+-+ Venus Chione.—Tue Cutone Venus. Plate I. fig. 4. (Cytherea Chione, Lamarck.) Shell strong, sub-cordated, somewhat concentrically wrinkled, margin entire, covered with asmooth, glossy, chestnut-coloured epidermis; sometimes a little radiated ; beneath which the shell is of a beautiful pale purple; apex turned sideways, with a cordiform depression ; umbo placed nearest one end. Inhabits the sea at Falmouth ‘in Cornwall, a a Summit, 0 6 lunule,2 anterior slope, & posterior slope, o disk, p margin * or limb. Venus compressa.— THE ComprEssEeD VENUs. Plate I. fig. 6. (Crassina compressa, Leach.) Shell strong, thick, sub- orbicular, compressed, and slightly sulcated or irregularly wrin- kled ; colour white, but is usually covered by a thick yellowish- brown epidermis ; umbo prominent, turning to one side, beneath which is a small cordiform depression ; hinge with two teeth in one valve, and a transverse one. Inhabits the British seas. c Sides, d base, e e cicatrix, g g teeth of the hinge, w the umbo. Venus decussata.—Tut Decussatep VENus. Plate I. fig. La) BIVALVE SHELLS. 3 8. Shell ovate, with decussate striz, angular before; apex turned to one side; umbo placed nearest one end; hinge fur- nished with three teeth in one valve ; posterior slope very minute and retuse; anterior slope long and narrow, with generally an inner blue margin. The outside is commonly of a plain rusty brown, and marked with purple zigzag lines. Two inches long and three broad. Inhabits the British seas, a Summit, e e cicatrix, g g g teeth of the hinge, 2 the inside. Venus aurea.—JTHE GoLpEN VeENus. Plate VI. fig. 10. Suborbicular, inequilateral transversely striated, and striated concentrically ; of a fine golden-yellow. One inch long, one and a half broad. Inhabits the British seas, The shells of this genus inhabit the ocean. They in general lurk iu the sand ; and many of the larger species are only to be found in very deep water, Genus 11.—SPONDYLUS. Animal a Tethys: shell hard, solid, and ridged, with unequal valves ; one yalve in general convex, and the other rather flat : hinge with two recurved teeth, separated by a small hollow. The shells of this genus inhabit the ocean. They adhere to rocks in deep water, and require considerable force to tear them from their retreats. Spondylus gederopus.—THs GaDEROPUS SponpyLus. Plate VI. fig. 11. Upper valve red, under one white with longitudin- al stri and ribs, rough granulations, and somewhat tongue- shaped, truncated spines, which are rather short. Three inches Jong. Inhabits the Mediterranean, and is considered excellent food by the Italians. It is sold in the markets at Nice, and other towns on the Mediterranean. Some of the Spondyli have ears, and others are devoid of them; they are in general strong, rugose shells. This genus requires considerable attention, as some of the species are sub- ject to such variety, that they are frequently mistaken for distinct shells. Genus 12.—-CHA MA. Animal a Tethys; shell bivalve, rather coarse ; hinge with a callous gibbosity, obliquely inserted into a slanting cavity ; an- terior slope closed. . Chama Cor.—Tue Heart Cuama. Pilate II. fig. 5. and 30 LINNEAN GENERA. plate VI. fig. 12. (Isoreardia Cor, Lamarck.) Shell sub-globose, beaks recurved ; anterior slope with a gaping fent, slightly wrinkled transversely, covered with a terra-sienna coloured epidermis ; umbo large and prominent, much contorted or incur- vated, turned to one side, and not touching when the valves are closed ; hinge strong, teeth flattish ; inside smooth, white ; margin plain. This is a very searce British shell; and has been found off the North Foreland, the Hebrides, and in the Irish Channel of large size. o Disk, rr beak. Plate IT. fig. 5. The shells of this genus inhabit the ocean; they live only in very deep water. The Chama Gigas, (Tridaena Gigas, Lamarck,) Giant Chama, is the largest and heaviest shell yet discovered, being sometimes of the amazing weight of 552 pounds, and the animal inhabitant so large as to furnish one hundred and twenty-two men witha meal ; it is said to be very palatable. Such is its strength that it is able to cut asunder a ship’s-cable. This species in- habits the Indian Ocean. Genus 13.—ARCA. Animal a Tethys; shell bivalve, equivalve; hinge with numerous sharp teeth, alternately inserted between each other. Arca Noe.—Noan’s Ark. Plate VI. fig. 12. Shell rhom- bic, reticulated, beaks near one end, incurved, very remote and separated by a deep groove; of a deep umber colour; orifices brown; and margin crenated. T'woinches broad. Inhabits the West Indian seas; also Britain—a small size. Linne divides this genus into two families: * with the margin entire ; ** with margin crenulated ; and has subdivided them as follows: + beaks recurved ; and ++ beaks infected. Some of the Arce are affixed by the foot of the animal to rocks; and others lurk in the sand or mud near the sea-shore, generally between high and low water mark. Genus 14.—OSTREA. Animal a Tethys: shell bivalve, generally with unequal valves, and slightly eared; hinge without teeth, but furnished with an ovate hollow, and for the most part lateral transverse grooves. The Ostrez are divided into three families: * valves radiated and eared, as in seallops ; ** rugged or rough, as in the oyster ; *** hinge with a per- pendicular furrowed line, asin thespecies of the genus Perna. The first family is again subdivided into three sections : + valves equilateral, and ears equal ; BYVALVE SHELLS. 37 +} ears unequal, and having one of them generally ciliated with spires with. in; +++ valves gibbous on one side. Ostrea Levis—Tur Smooru Ostrea. Plate II. fig. 2. (Pecten Levis, Lamarck.) Shell thin, flat, sub-orbicular, and pellucid, longitudinally and transversely striated ; one ear con- siderably larger than the other; colour various, sometimes orange, dark pink, &c. Not uncommon on the coast of Northumber- land. The striz on this shell are so minute, that they can seldom be seen with the naked eye. F Longitudinal and transverse strie, H H ears or auricles. Ostrea Opercularis.—Tue Lip Ostrea. Plate VII. fig. 14. Mars nearly equal ; shell with about twenty rounded ribs finely striated longitudinally and transversely ; beautifully variegated with red, orange, purple or brown ; upper valve somewhat con- vex. Inside pure white. Three inches long. JIuhabits the British Seas. The Ostreze inhabit the ocean; some lurk in the sand in large beds, others adhere to rocks, and some to the mangrove trees which overhang the sea on the shores of the West Indies. The Edible Oysters of Britain, are said to be superior to those of all other countries, and are common on many of our coasts. Indeed, this country has been noted for oysters from the time of Juvenal, who flourished in the he- ginning of the second century ; in satirizing Montanus, an epicure, he says: He, whether Circe’s rock his oysters bore, Or Lucrine lake, or distant Richborough’s shore, Knew at first taste. The luxurious Romans were very fond of oysters, and had their layers or stews for them as we have at the present time. Sergius Orata was the first inventor, as early as the time of L. Crassus the orator. He did not make them for the sake of indulging his appetite, but through avarice, and enjoyed great profits from them. Orata got much credit for his Lucrine oysters, for, says Pliny, the British were not then known. The oyster is a very entertaining object to those who are fond of micros- copic investigation. In the clear liquor around the animal, many minute, round, living arima!cules have been found, whose bodies being conjoined, form spherical figures with tails, not changing their place otherwise than by sinking to the bottom, being heavier than the fluid; these have been fre. quently seen separating, and coming together again. In other oysters, animalcules of the same kind were found not conjoined, but swimming by one another, where they seemed in a more perfect state, and were judged by Leeuwenhoek to be the animalcules in the roe or semen of the oyster. A female oyster being opened, incredible numbers of small oysters were seen, covered with little shells, perfectly transparent, and swimming along slowly in the liquor; and in another female, the young ones were found of a brown colour, and without any appearance of life or motion. In the month of August oysters are supposed to breed, because young ones are then found in them. WLeeuwenhceek, on the 4th of August, opened D 38 LINNEAN GENERA. an oyster, and took ont of it a prodigious number of minute oysters, all alive, and swimming nimbly about in the liquor, by means of certain ex- ceeding small organs extending alittle way beyond their shells; and these he calls their beards. In these little oysters he could-discover the joinings of the shells; and perceived that there were some dead ones, with their shells gaping. These, though so extremely minute, are seen to be as like the large oyster, as one egg is like another. As to their size, he computes, that 120 of them in a row would extend an inch ; and cousequently, that a globular body, whose diameter is an inch, would, if they were also round, be equal to 1,728,000 of them. He reckons 3000 or 4000 are in one oyster, and found many of the embryo oysters among the brairds; some fastened thereto by slender filaments, and others lying loose, he likewise found animalcules in the liquor 500 times less than the embryo oysters. Genus 15.—ANOMIA. Animal an emarginate siliate strap-shaped body, with bristles or fringea affixed to the upper valve ; arms two, linear, longer than the body, connivent, projecting alternate on the valve and ciliate on each side, the fringe affixed to each valve; shell bivalve, inequivalve, one of the valves flattish, the other gibbous at the base with a produced beak, generally curved over the hinge; one of the valves often perforated near the base ; hinge with a linear prominent cicatrix, and a lateral tooth placed within, but in the flat valve on the very margin; two bony rays for the base of the animal. Plate VII. fig. 15. Anomia Undulata.—Tue Wavep Anomia. Plate VII. fig. 15. Sub-orbicular, with fine irregular, undulated, longitudinal, smooth striw, crossing transverse curved ones ; inside pearly shining green. One and a-half inch wide. Inhabits the Bri- tish seas. Anomia Ephippum.—TuHE SapDLE ANnomiaA. Pilate L fig. 7. Shell sub-orbicular, irregularly wrinkled, and waved; upper valve convex, under flat and perforated at the hinge, through which the ligament passes by which it is affixed to other bodies ; inside pearlaceous, and of various changing colours ; green, pur- ple, violet or yellow. Often to be met with adhering to the common oyster, or ostrea maxima. a Base, m ligameut perforation. The Anomiz inhabit the ocean. The animal attaches itself to fuci, shells, stones, and other extraneous bodies at the bottom of the sea: they are generally affixed by a testaceous plug, which adheres to one of the muscles of the animal and passes through the perforation in the flat valve, BIVALVE SHELLS. 39 Genus 16.—MYTILUS. Animal allied to an Ascidia; shell bivalve, rough, generally affixed to other bodies by a byssus or beard of silky filaments ; hinge mostly without teeth, having a subulate, excavated, longitudinal line. Plate VII. fig. 16. The Linnean Mytili are divided into three families : * parasitical, affixed as it were by claws, as exemplified in the Mytilus Crista Galli; ** flat or com- pressed into a flattened form, and slighted eared; as in the Mytilus Mar- garitiferus ; *** elongated, ventricose, or convex, as in Mytilus Edulis. Mytilus edulis. —Tue Episte Muscie. Plate IL fig. 4. and 6. Shell oblong, pointed at the beak, sides much sloped; an- terior side a little angulated ; smooth, and radiated with deep blue or purple; covered with an umber coloured epidermis. Inside, round the margin, of a fine blue, which grows gradually lighter towards the centre; cicatrix very distinct and glossy ; beneath the beak are several crenulations, which some have supposed to be teeth. This is the most common shell we have, and well known by the name of muscle. It forms a pleasant and nutritious food. They have, however, in some localities proved poisonous, and fatal consequences have followed eating them. The true nature of this poison has not yet been satisfactorily accounted for. Plate Il. fig. 4 and 6. a The cartilage, r r length of the shell, u u breadth of the shell, o disk, r r the beak. Mytilus Incurvatus.—Tue Incurvatep Myrius. Plate VII. fig. 16. Oblong oval, nearly smooth, both valves much inflated, and curved on one side near the ligament, apex acute, and base much widened. Inhabits the British coasts. Pro- bably it is only a variety of the Mytilus edulis. It is to the Mytilus Margaritiferus, (the Meleagrina margaritifera of Lamarck,) Plate X. fig. 10. that we are indebted for that precious gem, the real pearl. It is an inhabitant of the Indian ocean; where it is regularly fished for by men who dive to the bottom of the sea,in places where it fre- guents. In this perilous employment, the divers are often attacked by sharks, and not unfrequently lose their lives.—Mother of pearl ornaments are made from the shell itself. The Mytili inhabit the ocean, Iskes, rivers and ponds. Marine muscles adhere to rocks or beds by a thin but very tenaceous byssus, consisting of extremely fine and tough filaments, and some to the Gergonize by claws. Some penetrate caleareons and argilaceous rocks, where they reside without changing place, others adhere to recks or clay onthe shore. They are much used for bait or food, and as such they are esteemed by many. The fresh water muscles are generally found on the surface, or a little way under the mud. Most species of muscles produce pearls. D2 AS LINNEAN GENERA. Genus 1'7.—PINNA. Animal a Limax; shell sub-bivalve, fragil, upright, gaping at one end, and furnished with a silky byssus or beard: hinge without teeth. Pinna pectinataa—Tuer PrctinateD Pinna. Plate VIL. fig. 17. ‘Thin, pellucid, light horn coloured ; longitudinally rib- bed, and spinous for half its width, obliquely striated, transversely on the other half. Six and a-half inches long and three broad. Inhabits the British seas. The Pinnz, which frequently grow to a large size, only inhabit the ocean. They are generally found standing erect in the smoother water bays, with the broad end or base of the shell uppermost. They are sometimes affixed by their byssus or beard, to rocks or other bodies, and so firmly attached, that they can by no means be disengaged but at the will of the animal. In Italy the byssus of the Pinna is woven into a sort of silk. The fibres or filaments of which it is composed, are very tough, and of a fine glossy brown colour. The ancient Romans highly esteemed articles made of this byssus ; and at Naples and Palermo there are still manufactories of it. Stock- ings, gloves, and even a fabric resembling sarsnet are made from it; and also an imitation of bread cloths. This latter stuff is very expensive, a coat being about the value of ten pounds of English money. The pinna has obtained among the Italians a little reputation for the prac- tice of some of the nioral virtues, in treating a small species of crab with hospitality and friendship, by receiving it into the shell, and defending it against its enemies. In return for this kindness, the crab, like the jackal with the lion, acts the part of a provider and monitor, by warning its host of the presence of its prey, or the approach of anenemy. But this friendly intercourse, like the fabulous account of the lion and jackal, accords ill with the nature of the animals between whom it is practised. The crab, it is far more probable, is a troublesome intruder ; and, notwithstanding all the service he can repay, is considered a very unwelcome guest, and is indebted for his lodging to his activity and instinctive sagacity in providing for his own personal safety ; retaining possession from the sluggish nature of his host, rather than to his kindness and hospitality. Genus 18.—A RGONAUTA. Animal a Sepia or Clio; shell univalve, spiral, involute, membranaceous, and unilocular, or consisting of a single apart- ment or cell, Argonauta Argus.—TuE Arcus ArconavtTa. Plate VII. fig. 18. Inyolute, extremely fragile, white, ribbed, and obsoletely striated; the keels approximate and tuberculated, from six to eight inches in diameter ; inhabits the Mediterranean. The Argonauta argus, or Paper Nautilus, is the Nautilus so famous UNIVALVE SHELLS. Al amongst the ancients, and frequently mentioned in the writings of Pliny and others. The singular structure and wonderful economy of this animal very early attracted the attention of naturalists. To its progressive motion on the surface of the ocean mankind are indebted, it is said, for the first hint of using sails in navigation. This is alluded to by Pope, in the following lines : Learn of the little Nautilus to sail, Spread the thin oar, and catch the driving gale. What the particular organization is which enables this animal to rise to the surface, or to sink to the bottom of the ocean at pleasure, has not yet been-satisfactorily accounted for by naturalists ; whether it is by throwing out a quantity of water, by which it becomes specifically lighter than the element in which it lives, or by taking in a quantity of air, which will pro- duce the same effect. It is only when the sea is ealm and unruffled that the Argonauta, with his feeble bark, appears on the surface. In rising through the water, the shell is reversed, the sharp edge of the keel present- ing less resistance to the liquid, and when it reaches the surface, the animal, by exerting its arms, restores it to a proper position for its voyage. A quan- tity of water is taken into the shell to balance it; the animal then em- ploys its arms as oars ; or if a gentle breeze sweep the surface, it erects an ovate extensible membrane, at the extremity of the tentacula, in the man. ner of a sail, while its arms serve as oars to direct its course, or to keep the shell steady, as well as part of the body which hangs over the shell and serves to act the part of arudder. Thus equipped, the solitary navigator, in his little galley, impelled by the breeze, glides smoothly along the busom of the ocean. But on the approach of the smallest danger, it instantly re- tires within its shell, and, taking in a quantity of water, or ejecting a volume of air, quick as thought it sinks to the bottom. In fine weather this shell is frequently to be met with in the Mediterranean, and has obtained amongst seamen the name of a Portuguese man-of-war Genus 19.—NAUTILUS. Animal unknown. Shell univalve, divided into several com- partments, communicating with each other by siphunculus or aperture. The Linnean Nautili are divided into two families, *spiral and rounded, **elongated and straight. Ofthe former there are two sections : +whorls contiguous, ++whorls separated. Nautilus pompilius.—Tue Pompitius Nauritus. Plate VII. fig. 19. With the aperture heart-shaped, the spire involute and concealed, pale yellow with mixed streaks and undulations of bright chestnut ; aperture pearly and shining, within from five to eight inches in diameter. Inhabits the East Indian ocean. Plate III. fig. 3. represents this shell with the lip cut straight, and a piece removed from the side, to show the involuted spire. ce aperture, ¢ involuted spire. D3 42 LINNEAN GENERA. Nautilus spirula,—TueE Sprrat Navurtitus. Plate III. fig. 11. (Spirula Peronii, Lamarck.) Aperture of the shell erbicular ; whorls cylindrical, separated, and gradually decreasing inwards, the first a little straight ; siphunculus contiguous to the walls of the shell; outside of a pale cream colour, pearlaceous within. Inhabits the American and Indian oceans. v Siphunculus, w ww w w chambers. The curious structure of the shell ef the Nautilus Pompilius, (which also runs, with some variation, through the whole genus,) cannot be con- templated without admiration, each cell or camera communicating with the next by a small and short tube, the first or principal cell being far larger than the rest, and appearing destined to contain the chief part or body of the inhabiting animal, the nature of which is not yet properly understood, appears, however, to be in some degree allied tu the genus Sepia, but is desti- tute of Jong arms or claspers, instead of which it is furnished with several rows of short, broad, subdivided or palmated tentacula, spreading in a ra- diated direction round the mouth or beak: itis also provided with a con- eave expansile hood or precess, which it is supposed occasionally to extend by way of a sail. The animal is figured in Shaw’s Nat. Misc. Plates 579 and 580. Its cclour is deep pink. With a very few exceptions the Nautili have only been found to inhabit the ocean. Genus 20.—CONUS. Animal a Limax; shell univalve, convolute, turbinate ; aperture effuse, longitudinal, linear, without teeth, entire at the base ; pillar smooth. This genus in the Linnean System is divided into five families : *having the spire or turban nearly truncate or flat; **pyriform, with the base rotun- date, and sub-cylindrical, the cylinder one half longer than the spire ; #** elongate, with the base rotuudate, cylinder twice the length of the spire ; ***#ventricose in the middle, and narrow at each end; *****ventricose, and emits a tinkling sound when thrown on its back upon a table. Conus striatus. —THE STRIATED ConE. Plate VIII. fig. 20. Ovate, oblong, gibbous, clouded, and with strong transverse striz. Four inches long. Inhabits Africa and India. Conus varius. Plate II. fig. 12. Rubbed through to show the internal structure of the shell. pb Spire, F body, M M M pil- lar or columella. The Cones inhabit the ocean, and are generally found on rocky shores. ‘Many of the Cones are very beautiful. Some of them are the highest priced of all shells, from their great rarity. One species, the Cedo Nulli of Lyonet, is valued at one hundred guineas. Cones are covered with an epidermis, and it is not till this is remoyed that their beanty can be seen. UNIVALVE SHELLS. AS Their surface is highly polished, contributing much to heighten the delicate and glowing tints which are diffused over some of the finer species in an in- finite variety of undulations, clouds, spots, and bands. Genus 21.—CYPRAA. Animal a slug ; shell univalve, involute, sub-ovate, smooth, obtuse at each end; aperture effuse at both extremities, linear, extending the whole length of the shell, and dentated or toothed on each side. Linne divides the genus Cyprza into four families: *mucronate, or point- ed; **obtuse, and without any manifest spire ; ***umbilicated, or with a small perforation ; ****marginated. The genus Cyprza consists of beautifully coloured, and very highly polish- ed shells. It is said, that they leave their shells annually, and construct new and larger ones. But we have not been able te ascertain this point asa fact. They live in sand at the bottom of the sea; the animals are provided with a membrane, which they throw over their shells, which preserves the fine polish, and prevents other testaceous bodies from fixing on them. The Cyprea have only been found to inhabit the ocean. Cyprea Europea.—Tue European Cyprma. Plate VIII. fig. 21. With numerous transverse furrows, tumid on the back, pale purple or whitish, and generally with three dark blackish brown spots. Half aninch long. Inhabits the British seas. Genus 22.—BULLA. Animal a Limax; shell univalve, convolute, and unarmed with teeth; aperture a little straitened, oblong, longitudinal, very entire at the base; pillar oblique and smooth. Bulla Catena.—Tue Caan Buta. Plate VIII. fig. 22. (Bullza Catena, Lamarck.) Ovate, white, pellucid, with a minute chain-like transverse strie; aperture extremely large, obtuse at the top, with a single volution one-fourth of an inch long. Inhabits the British seas. The shells composing the genus Bulla inhabit the ocean, lakes, rivers, ard ditches. The marine species are found afew inches under the sand. Some of the species may be frequently taken alive in little pools, between high and low water-mark, in which they are often seen sporting, with a very rapid motion in the sunbeams. The animal inhabiting the Bulla is considerably too large for its shell, and cannot contract itself wholly within it, as most other animals which have a testaceous covering can do, 44 LINNEAN GENERA. Genus 23.—VOLUTA. Animal a Limax; shell single celled and spiral; aperture without a beak and somewhat effuse ; pillar twisted or plaited, generally without lips or perforation. Linne divides this very extensive genus of shells into five distinct families : *aperture or opening entire; **somewhat cylindrical and emarginate ; **kobovate, effuse, and emarginate ; ****fusiform ; *****ventricose, spire papillary at the top. Voluta episcopalis. , THE Episcopat Votura. Plate VIII. fig. 29. (Mitra episcopalis, Lamarck.) Emarginated, smooth, margin of the volutions entire ; lip denticulated ; columella with four plaits. Five inches long. Inhabits the Indianocean. Vari- ously spotted with orange. Voluta oliva. Tur Oxtve Votura. Plate II. fig. 7. (Oliva, Lamarck.) Shell smocth and glossy; spire reflected at the base ; pillar with four plaits; clouded, or covered with zigzag or waved lines of a pale brown colour. Found in the Indian seas, in endless varieties of colours and markings. A Apex, 1 front, N outer lip, z plaits of the pillar-lip or columella. The Volutes have only been found in the ocean, and are most common in inter-tropical climates. Genus 24.—BUCCINUM. Animal a Limax; shell univalve, spiral, gibbous; aperture ovate terminating in a short canal, leaning to the right, with a retuse beak or projection ; pillar-lip expanded. The Buccina are divided by Linne into nine families: *inflated, rounded, thin, sub-diaphanous, and brittle ; ** with a short, excerted, reflected beak, lip unarmed outwardly ; *** lip aculeated on the outside of the posterior part ; in other respects resembling the last division ; **** pillar-lip dilated and thickened ; ***** pillar-lip appearing as if worn flat; ****** smooth, and not enumerated in the former divisions ; *******angular, and not includ- ed in the former divisions ; ********tapering, subulate, and smooth. Bucciaum Lapillus.—Tue Srone Buccinum. Plate VIII. fig. 24. (Purpura Lapillus, Lamarck.) Oval, pointed, spirally ridged, and faintly striated ; columella broad, flattish, and im- pressed near the top: yellow, white, chestnut, orange or brown, sometimes with spiral bands ; aperture oval, acute, lip thin, and slightly crenate. One inch long. Inhabits the European seas. This is one of the shells, fom which the ancients are supposed to have ex- tracted their indelible purple dye, called the Tyrian purple. The part con- UNIVALVE SHELLS. 45 taining the colouring matter, is a longitudinal vein, just under the skin on the back, behind the head, appearing whiter than the rest of the animal. If the vein is laid open with a needle, a tenacious yellow matter will flow, which being applied with a hair pencil to linen, silk, or paper, will in a short time become of a bright yellow, will soon change to pale green, then as- sume a bluish cast, and afterwards a deep and brilliant purple. ‘These changes are more or less accelerated by the presence or absence of the solar rays: but even without the influence of the sun, it will go through all these changes in two or three hours. Neither air, light, nor washing can after- wards alter its hue. The Buccina generally inhabit the ocean, with the exception of a very few species, which are found on the earth. Buccinum Undatum.—Tue Wavep Buccinum. Plate II. fig. 10. Shell with from seven to eight ventricose volutions, and undulated ribs ; transversely striated, and crossed with fine longi- tudinal strize ; pillar-lip reflected, and glabrous. Inside white, and deep yellow in some. Four inches long. A common shell on most of the British shores F Body, M the pillar or columella, Q canal or gutter. Genus 25.—STROMBUS. Animal a Limax ;—shell univalve and spiral; aperture much dilated ; the lip expanding and produced into a groove leaning to the left. Linne divides the Strombi into four families : *lip projecting into linear divisions or claws ; **lobed ; ***dilated ; ****tapering, with a very long spire. Strombus Pes-Pelicani.—Petican’s Foor Stromsus. Plate VIII. fig. 25, (Rostellaria Pes-Pelicani, Lamarck.) Volutions surrounded by a row of tubercles ; lip expanded into four pal- mate angular claws ; body with two rows of tubercles, grey or reddish-brown. T’woincheslong. Inhabits the British coasts. The shells composing this genus inhabit the ocean, and are in general found on rocky shores. Strombus pugilis.—Tue Ficutinc Srromegus. Plate III. fig. 8. Anterior lip prominent, rounded, smooth ; spire spinous ; beak three-lobed, obtuse, flesh-coloured, reddish or brownish, within paler and polished ; back smooth; first whorl of the spire crowned with spines, which in the others grow gradually less ; the outermost whorl cancellate ; pillar-lip much reflected ; three and a half inches long. Inhabits Seuth America, and the shores of the West India islands, 46 LINNEAN GENERA. D Spire, 1 front, NN N the outer lip, 0 pillar-lip, @ canal or gutter. ° The young shells of this genus want the dilated lip, which is one of the most essential characters of the strombi, and are in consequence often con- founded with the genera Buccinum and Murex. Genus 26.—MUREX. Animal a Limax; shell univalve, spiral, rough, with mem- braneous sutures ; aperture oval, ending in an entire straight o1 slightly ascending canal. ; Linne divides the Murices into six families: *spinous, with a produced beak; **sutures expanding into crisped foliations ; beak abbreviated ; *k*ventricose, with thick protuberant rounded sutures; ****more or less spinous, and without manifest beak ; *****with a long, straight, subulate, closed beak, and unarmed with spines; ******tapering, subulate, witha very short beak. Murex antiquus.—TuHE ANnTIQUATED Murex. Plate VIII. fig. 26. (Fusus antiquus, Lamarck.) Oblong, transversely striat- ed; beak elongated; spire with seven or eight cylindrical volu- tions: yellowish white, saffron-yellow, with margin of outer lip acute, and entire. From six to eight inches long.—Inhabits the British coasts, Murex muricatus:—Tue Mouricatep Murex. Plate II. fig. 11. Shell strong and rough, with from six to seven ventri- cose, tuberculated volutions, tapering to a fine point; the tuber- cles are formed by interrupted, longitudinal ribs, crossed by strong elevated striz, and in some parts are pointed or angulated; apex smooth; aperture oval, terminating in a long slender canal; outer lip sharp and dentated at the edge, margin within crenulated ; pillar-lip smooth. Inhabits the British seas, ra. ther a local shell. B Base, c aperture, K K &c. sides, p the beak or rostrum, Q canal or gut- ter. The Murices are only found inthe ocean. They in general frequent rocky hores and some of them burrow in the sand. Genus 27 — TROCHUS: Animal a Limax; shell univalve, spiral, more or less conic; aperture somewhat angular or rounded, the upper side trans- verse and contracted ; pillar placed obliquely. Linne divides the Trochi into three families : *umbilicated, erect, with pil- lar perforated ; **imperforate, erect, with the umbilicus closed ; ***taper- UNIVALVE SHELLS. 47 ing, with an inserted pillar, and falling on the side when placed upon the base. Trochus papillosus. Tur Pimptep Trocuus. Plate VIII. fig. 27. Conic, imperforate at the base, spirally granulated, and not marginated at the edges of the volutions; body tumid, and spire tapering abruptly to an acute apex, flesh-coloured; one and a half inches long. : Trochus umbilicatus.—TuE UmnpiticaTeD Trocuus. Plate III. fig. 1. Shell conico-convex, flattish, rounded at the top ; apex depressed, volutions five, slightly emarginate, defined by a fine line; spirally striated, rather whitish, with zigzag lines of purple; aperture compressed and angulated; with a large um- bilicus which extends to the apex, Found on the Northumber- land and Yorkshire coasts. c Aperture, uU umbilicus. The Trochi inhabit the ocean, with the exception of a few land species. They generally frequent pools, which are wet when the tide recedes ; some few of them live in very deep water. Genus. 28.—TURBO. Animal a Limax; shell univalve, spiral, and solid; aperture contracted, orbicular, entire. The shells composing this genus are divided into five families: *with the pillar-margin of the aperture dilated and imperforate ; **solid and imperfo- rate ; **solid, perforated ; ****cancellated ; *****tapering. Turbo rudis.—Tue Rustic Turso. Plate IX. fig. 28. Sub- oval, faintly striated transversely, with five tumid volutions ; outer lip thick, glossy within; dull yellow, drab, or fawn colour- ed; volutions separated by a deep suture. ‘Three-fourths of an inch long; inhabits the British coasts. Turbo terebra.—Tue WimstE Torso. Plate III. fig. 9. (Turritella terebra, Lamarck.) ‘Taper, pointed, with twelve or sixteen volutions, and numerous strong, spiral striz, the inter- mediate spaces are prominent and acute ; white, reddish or cream coloured; one and a half inches long. Inhabits the British seas. This figure is polished down, to show the internal structure of the columella, r. body; MM M, columella. Turbo costatus.—-THeE Rissep Turzso. Plate III. fig. 12. (Pyramis costatus, Brown.) Shell sub-pellucid, white, and subturreted ; volutions five, with prominent, longitudinal ribs, a 48 LINNEAN GENERA. little oblique ; apex obtuse ; aperture sub-orbicular, with a thick suleated margin. Found on the Coasts of Pembrokeshire, Dorsetshire, and Nor- thumberland, RRRR. Ribs. Turbo labiatus.—Tuz Lirrep Turzo. Plate III. fig. 13. (Clausilia labiata, Lamarck.) Shell with nine reversed volu. tions or whorls, tapering to a fine point; colour light brown, with strong, regular, longitudinal striz; volutions flat, and se- parated by a fine obsolete line ; aperture sub-orbicular and white, with a sinus at the upper end, and two teeth-like lamine on the inner lip ; margin reflected, broad and thick. Found in Hyde Park, and the ozier grounds at Battersea in Surrey. Plate III. fig. 13. B Reversed or heterostrophe spire, a teeth of a univalve, The shells of this genus inhabit the sea, land, and fresh water ; they ad- here to rocks near the shore ; and some of them live in very deep water. The Turbo Scalaris, or wentletrap, is very much esteemed by collectors, and is rather a scarce shell. Genus 29.—HELIX. Animal a Limax; shell univalve, spiral, subdiaphanous, brit- tle; aperture contracted, semilunar or roundish. Linne divides the Heiices into six families: *angulated on both sides ; ** whorls with a carinate acute margin; ***whorls rounded and umbili- eated; ****rounded and imperforate; *****tapering; ******ovate and imperforate. Helix arbustorum.—Tue Grove HeEttx. Plate IX. fig. 29. Sub-globose, sub-pellucid, with five volutions ; mottled with ash- colour, and streaked with deep chestnut zigzag lines; a single deep brown band commences at the edge of the outer lip, and continues round the middle of the body and the volutions to the apex; 3ths of an inch in diameter. Inhabits groves in Britain. Helix vivipara.—Tue Vivirarous Hetrx. Plate II. fig. 8. (Paludina vivipara, Lamarck.) Shell with six ventricose whorls, separated by a deep depressed line ; sub-ovate and obtuse; of an olive-green, with generally three fascize or bands on the bo- dy of the shell, and two on the superior volutions, which become obscure in the fourth; slightly wrinkled transversely; aperture sub-orbicular; pillar-lip reflected: sub-umbilicated. Found in the Thames and New River. A Apex, £ base, L a whorl, R R bands or fascie. UNIVALVE SHELLS. 4G Helix polita.—-Tue Po.isnep Herrx. Plate II. fig. 9. (Py- ramis politus, Brown.) Shell strong, white, glossy and smooth, with from nine to twelve volutions, scarcely defined by a separ- ating line, slender aud gradually tapering to a point; aperture oval, outer lip thick, but not marginated, inner or pillar-lip repli- cated. Found in Devonshire, Dorsetshire, Northumberland, and at Dunbar in Scotland. A Apex, B base, E £ suture of the spire or whorls, c aperture. Helix nemoralis—Tue Woop He rx. Plate III. fig. 2. Shelli imperforate sub-globose, thin and sub-pellucid, colour va- rious ; volutions five, with frem one to five dark brown bands or fascie ; aperture pyriform; inner margin of the lip sometimes white, in others dark-reddish brown. This shell is very com- mon in the evenings and mornings in summer, at the roots of hedges, &ce. Nn Outer lip, x epidermis, Y epidermis removed. Helix glutinosa.— Tue Giutinous Hetrx. Plate III. fig. 5. (Lymnza glutinosa, Lamarck). Shell suborbicular, thin, and diaphanous, of a glossy, pale horn-colour, smooth, but sometimes with obsolete wrinkles ; the body very large; spire very small ; volutions three; aperture very large, extending nearly to the apex. Found by Mr Montagu, in the marshes at Deal. G The back, H the venter, L whorl or volution. Helix puiris—Tue Dircn Hectrx. Plate III. fig. 10. (Lymnza ovata, Lamarck.) Shell sub-pellucid, and horn-co- loured ; spire with four volutions ; the body tumid and large; wrinkled longitudinally; apex very small, fine and pointed, aperture oval and large, outer-lip very thin ; outside covered with a dusky epidermis, inside pale, yellow, and very glossy. Common in most ponds, ditches, &c. Helix planorbis-—THE FLATTENED Hetrx. Plate III. fig. 14. (Planorbis carinatus, Lamarck.) Shell depressed and sub- pellucid, horn-coloured, rufous, or light chestnut brown; gene- rally with a light umber-coloured epidermis ; volutions five, pla- ced laterally on each other, gradually decreasing to the centre, making the shell concave at top, rounded and defined by the su- ture; striated across the whorls; a carinated ridge round the margin at the base; aperture angulated, and slanting towards the base. Inhabits ponds, rivers, and ditches in Britain. Helix subulata.—Tue AwL-Suarep Hetix. Plate IIT. fig. E 50 LINNEAN GENERA. 7. (Pyramis subulatus, Brown.) Shell tapering and subulate, very smooth, and glossy; whorls about ten, and scarcely defined; colour white, with two pale-chestnut spiral lines running from the body to the apex, becoming very faint on the upper whorls ; aperture ovate, and rather contracted. Length three quarters of aninch. Inhabits the sea at Weymouth and the Frith of Forth. D Spire, F body, o pillar-lip. Habitation. The Helices are found in the ocean, in lakes, rivers, and on the land. They are inhabitants ot almost all countries of the globe, and are in general very numerous. On land they are found to inhabit trees, old walls, mossy banks, rocks ; and are often found under stones. The animals of this genus are termed snails in Britain; they feed on vege- tables. It has been asserted, and on apparently good authority, that snails have been known to revive after remaining in torpidity for a number of years; snails are possessed of very considerable reproductive powers, and are capable of regenerating the head after it is taken off. Genus 30.—NERITA. Animal a Limax; shell univalve, spiral, gibbous, flattish at bottom; aperture semi-orbicular, or semilunar; pillar lip trans- versely truncate, flattish. This genus is divided into three families : *umbilicate ; **imporforate, with the lips toothless ; ***imperforate, with the lips toothed. Nerita littoralis.—THE Suore Nerira. Plate IX. fig. 30. (Neritoides littoralis, Brown.) Globular, thick, smooth ; spire flat ; yellow, covered with an olive epidermis, beneath which the shell is either yellow, orange or red, frequently with elegant zig- zag lines ofred, or brown. Three-fourths of an inch long. In- habits the British coasts. The Neritz inhabit the sea, lakes, and rivers. The marine species are found near the shore, and several are attached to mazine plants ; and some are only found in deep water, so that live specimens can only be had by trawling for them. Genus 31.—HALIOTIS. Animal a Limax; shell ear-shaped; univalve and dilated, with a longitudinal row of orifices along the surface; spire la- teral, and nearly concealed. The animals composing the shells of the genus Haliotis, inhabit the sea only. They adhere closely to rocks, and can only be removed by suddenly spatching them from their hold. In some places the animal is esteemed good eating. One species, the Haliotis tuberculata, is very common in Guernsey, and sold in the market as food, ~ SHELLS WITHOUT A REGULAR SPIRE. 51 Haliotis tuberculata.—Tue Turercutar Hatrioris. Plate IX. fig. 31. Dull reddish brown on the outside, sometimes clouded or mottled with a deeper shade : longitudinally striated, and trans- versely wrinkled, with a few raised tubercles ; inside pearlaceous, reflecting the most beautiful shades of pink, blue, green and yel- low ; aperture open the whole length of the shell, outer lip irreg- ular; from three to four inches long. Inhabits the sea at Guernsey. It is asserted, that as a new hole is added by the animal to the shell, it carefully closes up the next open one tothe spire ; by which means the num- ber of orifices is, in general, the same in all shells of one species. DIVISION SECOND.—SHELLS WITHOUT A REGULAR SPIRE, Genus 32.—PATELLA. Animal a Limax; shell univalve, subconic, shaped like a bason; without a spire. Linne divides this genus into five families: * farnished with an internal lip; shell entire; **with the margin angular or irregularly toothed ; *** with a pointed recurved tip or crewn ; **** very entire, and not pointed at the tip or vertex; ***** with the crown perforated. Patella vulgata.— Tut Common Paretia. Plate IX. fig. 32. Subject to great external variety ; ribbed from the vertex to the margin in some specimens, and with divergent striz ; others are striated merely without ribs; of a dark brown or olive green on the outside, and, the inside blue shining with deep purple radiations ; and subject to great variety of cclour ; apex obtuse and placed towards the narrow end of the shell, which is usually ovate. From one to twoinches long. Inhabits the shores of Northern Europe. Patella Chinensis—Tue Curese Patetra. Plate III. fig. 6. (Calyptrea sinense, Lamarck.) Shell sub-conic, sub- pellucid, and very thin, colour whitish, much compressed, round- ed at the margin; vertex central, terminating in a sub-spiral volution, with usually a number of concave scales. Inside white, glossy, and smooth, with a sub-spiral columella or pillar-lip, ex- tending from nearly the margin to the end, and forming the ex- ternal sub-volution ; it is broad, flat and oblique. Found in Helford harbour, Cornwall; in Saleomb bay, Devonshire, by Mr Montagu; and near Dunbar, by Captain Laskey. E2 52 LINNEAN GENERA. The shells of this genus inhabit the sea, lakes, and rivers. Those of the sea in general adhere to recks and stones on the shore; and are so tenacious, that they cannot be removed without breaking the shell, unless taken by surprise. These inhabiting fresh water are generally found attached to aquatic plants. The Patelle are called Limpets in Britain. w Chamber. Genus 33.—DENTALIUM. Animala Terebella; shell univalve, tubular, straight or slight- ly curved, with the cavity undivided, and open at both ends. Dentalium entalis.—Tue Toor Dentaurum. Plate IX. fig. 33. White or yellowish, slightly curved, and tapering toa fine point ; slightly striated. One and a-halfinchlong. Inha- bits the British seas. The shells of this genus are only found in the ocean. They are solitary, and lie in the mud, in an oblique or perpendicular position. Genus 34.—SERPULA. Animal a Terebella; shell univalve, tubular, generally ad- hering to other substances; often separated internally by divi- sions at uncertain distances. Serpula vermicularis—TuHe Worm-Like Serputa. Plate IX. fig. 34. White, cylindrical, tapering, and variously curved and twisted ; always affixed to other substances. Inhabits the British seas. The Serpulz inhabit the ocean. They generally adhere to stones, shells, and plants ; sometimes a plurality of species are found on one stone or sheil. There are also several species of Serpula which are unattached. Genus 35.—TEREDO. Animal a Terebella, with two calcareous, hemispherical valves cut off before, and two lanceolate ones: shell tapering, flexuous, and capable of penetrating wood. Teredo navalis—Tue Sup Terepo. Plate IX, fig. 35. Cylindrical, taper ; smooth, white, and flexuous, finely striated longitudinally, The shells of this genus inhabit the bottoms of ships ; and oak poles, which are under water in harbours and docks. One species has been found in the mud, at the bottom of the ocean. This last mentioned shell is the Teredo Gigantea, and has been described to consist of a tube, five feet four inches in length, nine inches in circumference at the larger, and two and one half inches at the smaller end, aud is the longest of all testaceous shells. LINNEAN GENERA OF SHELLS. 53 The Teredo Navalis, or ship-worm, insinuates itself into the bottoms of ships, even although the oak is perfectly sound, and in a very short time completely destroys it. ‘This destructive creature was originally brought by our vessels from tropical climates; but has now become an inhabitant of most of the harbours of this island, and is very common in Plymouth Dock It was first proved by that learned and very indefatigable naturalist, Colonel George Montagu, in his supplement to Testacea Britannica, that the animal inhabiting the Teredo, was not a Terebella, but an Ascidea. Genus 36.—SABELLA. Animal a Nereis, with a ringent mouth, and two thicker tentacula behind the head; shell tubular, composed of particles of sand, broken shells, and vegetable substances, united to a membrane by a glutinous cement. Sabella tubiformis.— Plate IX. fig. 36. These shells, (if they can be called so) inhabit the sea and fresh water ditches. The Linnean Sabell are not testaceous shells, but merely cover- ings made up of extraneous substances ; and may therefore fairly be ex- punged from the collection of the Conchologist. They are included in Lamarck’s class Annelides, from the formation of the animal. TABLE OF THE LINNEAN GENERA OF SHELLS, WITH LAMARCK’S DIVISIONS OF THESE GENERA: Chiton. /93 Panopea. /4h I. Carron, Cn F Gigelnper /hLe Gubicneies = Mya SAf oronula. natina. peas ye Lutraria, ~ /Z/ casta. 6) Iv. - part. a Lepis 4 Creusia. /J6 V. Mya, 3/ Amphidesma, /3 4 ‘| Pyrgoma. J part. } 3 | Anatifa. Fs Corbula. 7 ; Heluerpests & | Tito. /2Z imeras. yria. Otion. /% § Ue vuteelia: 49, ILI. cosa 34 Pholas. LEY V. Soren, Ff Soten. SEM Gastrochena. Anatina, par, E3 54 LINNEAN GENERA OF SHELLS. \ f Sanguinolaria/g4 Placuna. Souen. Cont. 33 5 Hiatella. /2, H Anomiah (Mya, part. | XV. Axor, 3} 4 Crania. | Anping ee ‘Terebratula.7Q I ait y 3 ries ¥0 bs ia. , a. VL TELLINA, 3. < pasieaiia veal [ Anodonta. 4 | Tellina. SVB Modiola. | Lucina. 45 XVI. Mytitus, 7 4 re 8 L en ae /2 Meleagri ihe lo, [ Ostrea, some.//O VII. Carpium 3 3 Cardium. /Z4 f Lutraria, /Z/ XVII. Pinna, £g Pinna. //G Limacina, yos" XVIII Argonauts, Argonauta. o& Carinaria. 97 ( Orthoceras.¢ 5° Nodosaria.p IX. NautiLus, Spirula. f Christellaria, 7740 Nautilus, a7 nearly all. Mactra. Kel, VIII. Mactra, 93 4 sone ad meee of: part. Petricola,part/. Crassatella. g eb. Conus, 42 Conus. i IX. Donax, JL Venerapis XXI. Cyprma, Cyprea.€Z haan! or Bullza. l Capsa. 473/ Acer. ulla. { Petricola, /3 Bumodys part. XXII Butta, 43 Achatina/4/ Venerupis, /3 | Physa, part. &6 part, = Ovula. Terebellur the f Ancia, jo iene! a 15 J opin DA if Ancilla X. Venus 3L Lucina, eH Tornatella.g 7 Donax, d Turbinella. 7 Crassina. / /36 » Cancellariz, is Cyrena, paF : Columbeila.% Galathea. XXIII VOLUTA, Mitra. Cyprina. ye Voluta. és vas i Marginella. 4, Venus. | Volvaria, ' lieatula. ae Achatina. fp XI. Sponpyius, 39 pin /12 Oliva. Concholepas. 7/ { Cardita. J2 ( a fy. 5 Isocardia. Phasianella. XI. Cuaua, 3 : Chama. | viata ZS | Tridacna. Yi Turbinella, 7 lL Hippopus.// part. eters a eee in ‘ Pectunculus. 1P ae t. XMIIL Arca. i yr a, par . Areca. , ‘INU rex, d He 36 } pe 4 3 XXIV. Buccinum, ; Lee A Cassidaria, ; Cocnllea. Vip Cassis, % Perna. Purpura. Malleus. Y Monoceras. y, XIV. Osrrea, J Pedum., Harpa. 4 Lima. Dolise, j Pecten. os Bucemum, 13 0 Gryphza. “ii Eburna, Ostrea. //79 Terebra, 6 ; LINNEAN GENERA OF SHELLS. 55 ( Pirena. LI ( Anostoma, Ve se dhe Vy | es Zz phe ctordh: 7 Pupa, some. 7/ H part. Bulimus. yy, XXV. SrRoMBUS. Rostellaria, 73 Succinea. vi Pteroceras.// 3 | Auricula. z o Strombus. J? i Cyclostoma. 7 ¢ ! Cassidaria, P H planar ae: 6% art, ymnea. L Parpura, 7 | HELIX, Cont. J he ane : § 7 rs) i Melanopsis. [ Pleurotomz. I] SS Uan $6 | Tashi 76 Valvata. | ¥ Fasciolaria. /4 4 Watton. aan) Sa XXVI. Murex Erie 5 Janthena. 84 4 Siruthiolard | Sigaretus. - $ 3 Ranella, Navicella. 4%- ! Murex. Le os Neriti 9 Triton. A| XXX. Nerira, ean gL rf Ricinula. 72 Natica, §4 Purpura, paré a ie lg a ecliee - XXXI. Hatrotis. Helictic” f2 olarinm, . | Rotella. / Lingula. Le f. 46\ Trochus. ¢g 4/\ Patella. /973 XXVII. Trocaus, 6 pen | Umbrella. /O0 2 ar ; Parmophorus. / i: | arto. part, LT Emarginula. “0 yal Cerithium, «¢ Fissurella. y part. XXXIL Paretia,f7 < Pileopsis. Pupa. ; Calyptrea. Cian /9/ ¥ ee f surieus “9 | Ancylus part. H Navieeli ar cfiene bak Stomatella § 3 part. / XXXIILDentatium,$2Devtalium. /4 § XXVIII Turso, d Paludina, &6 q Suan, 15, Sealaria. 3/7 Spirorbis