t A . v .1' THE LIBRARY OF THE UNIVERSITY OF CALIFORNIA PRESENTED BY PROF. CHARLES A. KOFOID AND MRS. PRUDENCE W. KOFOID /I. LAMARCK'S GENERA OF SHELLS, CATALOGUE OF SPECIES. TRANSLATED FROM THE FRENCH BY AUGUSTUS A. GOULD, M. D. BOSTON: ALLEN AND TICKNOR. 1833. Entered according to Act of Congress, in the year 1833, BT ALLEN & TICKNOR, In the Clerk's Office of the District Court of Massachusetts. BOSTON: TUTTLE AND WEEKS, PRINTE No. 8, School Street. L-31 Lib, INTRODUCTION. THE science of Conchology has, within a very short period, risen into notice amongst us, and has already become a fashionable study, extensively and passion- ately cultivated. The means of pursuing it, however, are very limited. Nearly all the works we have, and these are but few, are arranged on the Linna?an sys- tem. His arrangement of shells, like his arrangement of all the kingdoms of nature, is very simple, though very artificial. His divisions are few and comprehen- sive, soon acquired and easily retained. But no one makes any considerable advance in the study of Con- chology, before he discovers great discrepancy in indi- viduals belonging to the same Linnsean genus ; and he learns that there is another system, already in general use among naturalists, founded on natural characters, and more in accordance with the present state of knowledge. This system, or some modification of it, he finds is destined to supersede all others, and this he must learn. The works which contain it are in a foreign language, of considerable magnitude, and are possessed and read but by very few. So that the lim- ited knowledge of Lamarck's genera, which is ordina- rily acquired, is wholly traditional. P368784 Vl INTRODUCTION. To supply, in some measure, this deficiency, the following translation and abridgment of Lamarck's work has been made, containing the substance of three large octavo volumes in French. Two transla- tions, at least, have been made in England, both of which have been consulted. One by Crouch, beauti- fully illustrated, bears a high price, and is not easily obtained. The other by Mr Leach, published in num- bers, in the London Quarterly Journal of Science, &c., 1823, is of course seldom to be met with. Each of the above translations is illustrated by a figure of the type of each genus. To supply, in some degree, the omission of these engravings, a list of species has been affixed to each genus. The assis- tance which this may render will be readily perceived. The Linnsean genera and species are supposed to be more or less known. Now if we have what is called by Linnaeus, Venus Islandica, and we look at the list of species, we find it, not under Venus, but under Cyprina. Being thus certified of the genus, we study this shell instead of a plate, comparing it with the generic description, and thus have a type of the genus by which to arrange other individuals in our cabinet. Thus we may proceed with other genera and species. A plate exhibiting the parts of a shell, Wood's Synopsis of Lamarck's subdivision of the Linnaean genera, an index, showing also the accentuation and derivation of the generic names, and a glossary of technical terms, have also been annexed. A few more modern and well characterised genera have been placed in the margin J and other species than those described by Lamarck, have been added. Those at the end of the list, separated from the rest by a dash, are American species, described by Barnes, Say, INTRODUCTION. Vll Lea, Conrad and others, in American works, and not included in Lamarck's enumeration. This compilation is intended for those only who study recent shells, and not for those who would study that department of the animal kingdom which ordina- rily bears shells. All reference to the inhabiting ani- mal is therefore omitted, and those genera which bear no shell, or are only found in a fossil state, are merely defined in their proper places, and the names of fossil species are not mentioned. It is supposed that those who would pursue the study to these particu- lars, will have access to the original work. A. A. G, INDEX. Acasta, one of the Oceanides 7 A/cera, Gr. without a horn 61 Achatina 66 Alasmidonta, Gr. with- out a lateral tooth 38 Ammonites, ammon, a name of Jupiter 106 Ammonoceratites, Gr. the horn of Ammon 106 Amphidesma, Gr. liga- ment, external and in- ternal 16 Amphitrite, one of the Nereids 5 Ampullaria, ampulla, a wide mouthed bottle 71 Anastoma, Gr. mouth looking upwards 64 Anatifera,Gr. producing ducks 8 Anatina, anas, a duck 13 Ancillaria, from ancilla, a damsel 96 Ancylus, ancile, a sacred shield 60 Anodonta, Gr. having no teeth 38 Anomia, Gr. without law, anomalous 52 A'rca, Lat. a chest, or ark 32 Arenicola, Lat. inhabit- ing the sand 3 Argonauta, Gr. sailors in the ship Argo 107 Aspergillum,La£. a wa- tering pot 9 Auricula, Lat. a little ear 67 Avicula, Lat. a little bird 46 Baculites, baculum, a staff 107 Balanus, Lat. an acorn 7 Belemnites, Gr. a dart 99 Birostrites, Lat. double beaked 54 Buccinum, Lat. a trum- pet 89 Bulimus, Lat. insatiable thirst 65 Bulla, Lat. a bubble 61 Bullaea, Lat. like bulla 61 Calceola, Lat. a little shoe 54 Calyptraea, Gr. a cap for the head 60 Cancellaria, cancelli, like pales of a fence 81 Capsa, Lat. a coffer or box 23 Cardita, allied to car- dium 30 Cardium, Lat. a heart 29 Carinaria, carina, the keel of a vessel 108 Caroc611a,6rr. caracalla, a kind of hood 63 Xll INDEX. O'strea, Lat. an oyster 51 O'tion, Gr. a little ear 8 O'vula?from ovum, an egg 94 Paludina,palus, a marsh 70 Pandora, alluding to Pan- dora's box 17 Panopsea, Gr. all aperture 12 Parmacella, parma, a lit- tle shield 61 Parmophorus, Gr. shield bearing 59 Patella, Lat. a bason, the knee pan 58 Pecten, Lat. a comb 48 Pectinaria, pecten, a comb 4 Pectunculus, Lat. a shell fish 33 Pedum, Lat. a shep- herd's crook 47 Perna, Gr. a gammon of bacon, pig's foot 44 Petricola, Lat. inhabit- ing rocks 18 Phasianella, phasianus, a little pheasant 78 Pholas, Gr. a burrow — to pierce 11 Phyllidia 57 Phylliroe 108 Physa 68 Pillopsis, Gr. like a bon- net 60 Pinna, Lat. a plume or feather 43 Pirena, Gr. the point of a sword 70 Placentula, Lat. a little cake 104 Placuna, Gr. a broad table 52 PIagiostoma,Gr. oblique mouth 48 Planaxis, Lat. flattened axis ? 78 Planorbis, planus, and orbis, flat orb 68 Pleurobranchus, Gr. branehiaa at the side 59 Pleurotoma, Gr. having the edge cleft 80 Plicatula, plica, a fold or wrinkle 49 Pneumodermon, Gr. skin like lungs 57 Podopsis, Gr. like afoot 50 Pollicipes, polleXj the thumb and pes, the foot, great toe 8 Polygyra, Gr. many whorls 64 Polystomella, Gr. many mouthed 105 Psammdbia, Gr. living in sand 19 Pterocera, Gr. horned wing 85 Pterotrachea, Gr. wing- ed trachea 108 Pupa, Lat. a puppet 65 Purpura, Lat. a shell producing purple 87 Pyramidella, pyramis, a pyramid 67 Pyrgoma, Gr. a tower 8 Pyrula, pyrum, a little pear 81 Radiolites, radius, a ray 53 Ranella, a little frog 82 Renulites, from ren, the kidney 101 Ricinula, (ricinus,) like the castor oil seed 87 Rostellaria, (rostellum,) a little beak 84 Rotalites, (rota,) a wheel 103 Rotella, Lat. a very small wheel 76 Sabellaria, sabulum, coarse sand 4 Sanguinolana, sanguis, blood 19 Saxicava, saxum, a rock and cavo, to hollow 18 INDEX. Xlll Scalaria, scala, a flight of steps 75 Sepia, from sepio, to cover or conceal 108 Septaria, septum, a divi- sion 10 Serpula, serpulla, a ser- pent 5 Siderolites, from sidus, a star 104 Sigaretus 63 Siliquaria, siliqua, a bean pod 3 Solarium, Lat. a sun- dial 76 Solen, Gr. a pipe or tube 12 Solenomya, allied to so- len and mya 16 Sphaerulites, spherula, a little globe 53 Spirolinites, from spirula 102 Spirorbis, spira and orbis, a spiral orb 5 Spirula? Lat. a little spire 100 Spondylus, Gr. prickly head of an artichoke 49 Stomatella, Gr. a little mouth 63 Stomatia, Gr. like a mouth 64 Strombus, Lat. a sort of shell fish 85 Struthiolaria, Gr. an os- trich 82 Succinea, Lat. amber colored 66 Symphinota, Gr. united at the back 38 Tellenides, Gr. like tel- lina 21 Tellina, Gr. the name of a swift fish 20 Terebellum, Lat. a little auger 96 Terebella, Lat. a little auger 4 Terebratula, terebratus, pierced 55 Teredina, resembling teredo 10 Teredo, Gr. a worm that bores wood 11 Testacella, Lat. a little shell 61 Tornatella, torno, to turn in a lathe 74 Tridacna, Gr. three bites 41 Trigonia, Gr. three corners 35 Triton, Lat. a sea deity 84 Trochus, Lat. a child's top 76 Tubicinella, Lat. a little trumpet 6 Turbinella, like turbo 80 Turbo, Lat. a wreath 77 Turrilites, turris, a tow- er 107 Turritella, turris, a little tower 79 Umbrella, Lat. a little shade 59 Ungulina, ungula, a hoof 16 Unio, Lat. a pearl 36 Valvata, valva, a folding door 70 Vermetus, vermis a worm 75 Venericardia, allied to Venus and cardium 28 Venerupis, venus and rupis, Venus of the rocks 18 Venus, name of a God- dess, 27 Vermilia, vermis, a worm 5 Vitrina, vitrum, glass 62 Voluta, Lat. a volute or scroll 92 Volvaria, from volvo. to roll 94 Vorticialis, from vortex, a whirlpool 105 Vulsella, Lat. tweezers 52 Xll INDEX. O'strea, Lat. an oyster 51 O'tion, Gr. a little ear 8 O'vula,from ovunij an egg 94 Pa\udina,palus, a marsh 70 Pandora, alluding to Pan- dora's box 17 Panopa?a, Gr. all aperture 12 Parmacella, parma, a lit- tle shield 61 Parmophorus, Gr. shield bearing 59 Patella, Lat. a bason, the knee pan 58 Pecten, Lat. a comb 48 Pectinaria, pecten, a comb 4 Pectunculus, Lat. a shell fish 33 Pedum, Lat. a shep- herd's crook 47 Perna, Gr. a gammon of bacon, pig's foot 44 Petricola, Lat. inhabit- ing rocks 18 Phasianella, phasianus, a little pheasant 78 Pholas, Gr. a burrow — to pierce 11 Phyllidia 57 Phylliroe 108 Physa 68 Pillopsis, Gr. like a bon- net 60 Pinna, Lat. a plume or feather 43 Pirena, Gr. the point of a sword 70 Placentula, Lat. a little cake 104 Placuna, Gr. a broad table 52 PIagiostoma,Gr. oblique mouth 48 Pianaxis, Lat. flattened axis ? 78 Planorbis, planus, and orbis, flat orb 68 Pleurobranchus, Gr. branchia? at the side 59 Pleurotoma, Gr. having the edge cleft 80 Plicatula, plica, a fold or wrinkle 49 Pneumodermon, Gr. skin like lungs 57 Podopsis, Gr. like a foot 50 Pollicipes, polleXj the thumb 'and pes, the foot, great toe 8 Polygyra, Gr. many whorls 64 Polystomella, Gr. many mouthed 105 Psammdbia, Gr. living in sand 19 Pterocera, Gr. horned wing 85 Pterotrachea, Gr. wing- ed trachea 108 Pupa, Lat. a puppet 65 Piirpura, Lat. a shell producing purple 87 Pyramidella, pyramis, a pyramid 67 Pyrgoma, Gr. a tower 8 Pyrula, pyrum, a little pear 81 Radiolites, radius, a ray 53 Ranella, a little frog 82 Renulites, from ren, the kidney 101 Ricinula, (ricinus,) like the castor oil seed 87 Rostellaria, (rostellum,) a little beak 84 Rotalites, (rota,) a wheel 103 Rotella, Lat. a very small wheel 76 Sabellaria, sabulum, coarse sand 4 Sanguinolana, sanguis, blood 19 Saxicava, saxum, a rock and cavOj to hollow 18 INDEX. Xlll Scalaria, scala, a flight of steps 75 Sepia, from sepio, to cover or conceal 108 Septaria, septum, a divi- sion 10 Serpula, serpulla, a ser- pent 5 Siderolites, from sidus, a star 104 Sigaretus 63 Siliquaria, siliqua, a bean pod 3 Solarium, Lat. a sun- dial 76 Solen, Gr. a pipe or tube 12 Solenomya, allied to so- len and mya 16 Spha3rulites, spherula, a little globe 53 Spirolinites, from spirula 102 Spirorbis, spira and orbis, a spiral orb 5 Spirula, Lat. a little spire 100 Spondylus, Gr. prickly head of an artichoke 49 Stomatella, Gr. a little mouth 63 Stomatia, Gr. like a mouth 64 Strombus, Lat. a sort of shell fish 85 Struthiolaria, Gr. an os- trich 82 Succinea, Lat. amber colored 66 Symphinota, Gr. united at the back 38 Tellenides, Gr. like tel- lina 21 Tellina, Gr. the name of a swift fish 20 Terebellum, Lat. a little auger 96 Terebella, Lat. a little auger 4 Terebratula, terebratus, pierced 55 Teredina, resembling teredo 10 Teredo, Gr. a worm that bores wood 11 Testacella, Lat. a little shell 61 Tornatella, tornOj to turn in a lathe 74 Tridacna, Gr. three bites 41 Trigonia, Gr. three corners 35 Triton, Lat. a sea deity 84 Trochus, Lat. a child's top 76 Tubicinella, Lat. a little trumpet 6 Turbinella, like turbo 80 Turbo, Lat. a wreath 77 Turrilites, turris, a tow- er 107 Turritella, turris, a little tower 79 Umbrella, Lat. a little shade 59 Ungulina, ungula, a hoof 16 Unio, Lat. a pearl 36 Valvata, valva, a folding door 70 Vermetus, vermis a worm 75 Venericardia, allied to Venus and cardium 28 Venerupis, venus and rupis, Venus of the rocks 18 Venus, name of a God- dess, 27 Vermilia, vermis, a worm 5 Vitrina, vitrum, glass 62 Voluta, Lat. a volute or scroll 92 Volvaria, from volvo. to roll 94 Vorticialis, from vortex, a whirlpool 105 Vulsella, Lat. tweezers 52 EXPLANATION OF THE PLATE. a. Spire 6. Body whorl r. Area, or anterior slope 5. Areola, or posterior slope c. Beak t. Beaks d. Base u. Hinge c. Canal v. Ligament /. Aperture w. Disc g. Lahrum, or outer lip x. Umbo, or nates h. Labium, or columellar lip y. Base t. Whorls z. Length k. Suture a* Breadth I. Apex, or vertex b* Auricles m. Back c* Left valve n. Varices d* Right valve o. Columella e* Valves p. Septa, or dissepiments q. Umbilicus f* Lunutej or anus g* Corselet, or escutcheon SYNOPSIS LAMARCK'S ANALYSIS OF THE LINIMEAN GENERA. LINHJEUS. LAMAKCK. LINNAEUS. LAMARCK. Chiton. Chiton. Chitonellus. Donax. Donax. Capsa. f Tubicinella. Coronula. Petricola. ' Venus. Balanus. Venerupis. Acasta. Corbis. Lepas. Creusia. Lucina. Anatifera. Venus. 4 Crassina. Pollicipes. Galatea. Cineras. Cyprina. Otion. Cytherea. Venericardia. Pholas. Gastrochsna. gpondylus. \ Spondylus. Panopo3a. f Chama. Glycymeris. Cardita. Mya. Anatina. Cypricardia. Corbula. Chama. < Isocardia. Unio. Etheria. Hyria. Tridacna. Vulsella. [ Hippopus. f Solen. ( Area. Solen. < Sanguinolaria. . } Cucullea. ( Hiatella. *' ) Pectunculus. Tellina. ' Nucula. Tellenides. Ostraea,, Pandora. Crenatula. Tellina. Psammobia. Perna. Psammotea. nctrrpo Malleus. Cyclas. a> ' Pedum. Cyrena. Lima. Cardium. Cardiura. Gryphea. Pecten. f Mactra. Mactra. } Lutraria. Argonauta. ( Crassatella. Argonauta. Carinaria. 1 SYNOPSIS. Anomia. Mytilus. Pinna. Nautilus. Conus. Cypraea, Bulla. Yoluta. Euccinum. < Trochus. Nerita. I Anomia. Lacuna. Crania. Orbicula. Terebratula. Hyalaea. Mytilus. Saxicava. Anodonta. Iridina. Modiola. Avicula. Meleagrina. Pinna. Nautilus. Orthocera. Nodosaria. Spirula. Cristellaria. Orbiculina. Polystomella. Conus. Cypraea. f Bulla. Bullaea. Bulimus. ^ Achatina. Physa. I Ovula. |/rerebellum. " Voluta. Auricula. Ancilla. Tornatella. Turbinella. Cancellaria. Columbella. Mitra. Marginella. Volvaria. Oliva. Buccinum. Concholepas. Phasianella. Planaxis. Cassidaria. Cassis. Purpura. Monoceros^ Harpa. Dolium. K burn a. Terebra. Trochus. I Pyramidella*. 1 Solarium. [ Rotella. ( Nerita. \ Navicella. ) Neritina. ( Natica. f Strombusv j Pirena. Strombus. < Cerithium. Rostellaria. I Pteroceras. 'Murex. Fasciolaria. Fusus. Pyrula. Murex. « Siruthiolaria. Ranella. Triton. Ricinula. Pleurotoma, f Turbo. Pupa. Clausilia. Scalaria. Delphinula. Turritella. ' Helix. Paludina. Carocolla. Anastoma. Helicina. Bulimus. Succinea. Helix. < Cyclostoma. Planorbis. Lymnaea. Melauia. Melanopsia. Valvata. Ampullaria. Janthina. Sigaretus. Haliotis. 'Haliotis. Stomatia. 'Patella. Lingula. Umbrella. Parmoplioms. Patella. < Emarginula. Fissurella. Pileopsis. Calyptraa. Crepidula. Ancylus. Stomatella. Dentalium. Dentalium. f Serpula. Siliquaria. Spirorbis. Vermilia. Serpula.^ Aspergillum. Septafia. Vermetus. | Galeolaria. ^Magilus. Teredo. Teredo. Fistulana. GENERA OF SHELLS. ANNULATA Forms the Ninth Class of Lamarck's Division of the Animal Kingdom. SEDENTARY ANNULATA Compose the third Order of this class*. They are usually found attached to marine substances, and inhabit membranous or horny tubes, more or less encrusted with grains of sand and fragments of shells. DORSALIA. ARENICOLA — has no shell. SILIQUARIA. Shell tubular, irregularly con- torted, tapering posteriorly, sometimes spiral at base, open at its anterior extremity, having a longitudinal, subarticulate fissure throughout its length. S. anguina,. muricata, laevigata, terebella, lactea, lima, spinosa. 4 GENERA OF SHELLS. MALDANIA. Tube open at both extremities. CLYMENE. Tube slender, open at both ends, encrusted exteriorly with grains of sand and fragments of shells. C. amphistoma. DENTALIUM. Tube testaceous, nearly regu- lar, slightly curved, gradually tapering towards the posterior extremity, and open at both ends. (a.) Tube with longitudinal ribs or striae. D. elephantinum, aprinum, sulcatum, fasciatum, octo- gonum, cleforme, novemcostatum, scxangulare, striatum, dentalis, pseudo-antalis, radicula. (b.) Tube without ribs or strice. D. antalis, arietinum, corneum, nigrum, politum, ebur- neum, clava, fissura, coarctatum. AMPHITRITEA. Tube membranous or corneous ; more or less sandy. PECTINARIA. Tube an inverted cone, mem- branaceous or paper-like, sandy, not attached. P. belgica, capensis, SABELLARIA. Tubes numerous, united in a common honeycomb mass above ; composed of agglutinated grains of sand and fragments of shells ; orifices cup-shaped. S. alveolata, crassissima. TEREBELLA. Tube elongated, cylindrical, attenuated and pointed at base, membranous, GENERA OF SHELLS. 5 with grains of sand and fragments of shells adhering ; open at apex only. T. conchilega, cristate, ventricosa. AMPHITRITE. Tube elongated, cylindrical, attenuated at base, membranaceous or coria- ceous, generally naked exteriorly. A. ventilabrum, penicillus, magnifica, vesiculosa, voluta- cornis, infundibulum. SERPULEA. Tube solid and calcareous. SPIRORBIS. Tube testaceous, convoluted into an orbicular, discoidal spire ; flattened and fixed at base. S. nautiloides, spirillum, carinata, lamellosa, tricostale. SERPULA. Tubes solid, calcareous, irregu- larly convoluted, grouped or solitary, attached to marine bodies ; aperture terminal, rounded, very simple. S. vermicularis, fascicularis, intestinum, contortuplicata, plicaria, glomerata, decussata, protensa, infundibulum, annu- lata,cereolus,filograna,vermicella, filaria, pellucida, minima, echinata, sulcata, costalis, dentifera, sipho, arenaria. VERMILIA. Tube testaceous, cylindrical, in- sensibly tapering posteriorly, more or less con- torted, fixed by the side to marine bodies ; aperture rounded, margin often armed with one, two, or three teeth. V. rostrata, triquetra, bicarinata, eruca, subcrenata, plici- fera, scabra, toeniata. GENERA OF SHELLS. GALEOLARIA. Tubes testaceous, very nume- rous, cylindrical, subangular, raised, undated, grouped, fixed at base, open at summit ; aper- ture orbicular, edge terminating at one side by a tongue. Operculum furnished above with from five to nine pieces attached to the edge by one side. G. caespitosa, elongata. MAGILUS. Base of the shell convoluted into a short, oval, snail-like spiral ; four contiguous whorls convex, the last largest, and prolonged into an undulated tube. Tube convex above, carinated beneath, slightly depressed and plaited at the sides. Folds lamellar, undu- lated, thicker at one side than the other. M. antiquus. CLASS X. — CIRRHIPEDA. Shell sessile, or elevated on a flexible, tendinous pedicle, sometimes movable, sometimes fixed; the inside covered by the mantle of the animal. ORDER I. — SESSILE CIRRHIPEDA. Shells fixed on marine bodies. TUBICINELLA. Shell univalve, operculated, tubular, erect, surrounded with transverse ribs, GENERA OF SHELLS. 7 truncated at both extremities, open at summit, closed at base by a membrane. T. balaenarum. CORONULA. Shell sessile, apparently uni- valve, suborbicular, conoid or obtusely conic, truncated at extremities ; parietes very thick, interiorly excavated into longitudinal cells. Operculum with four obtuse valves. C. diadema, balgenaris, testudinaria, denticulata. BALANUS. Shell sessile, attached, univalve, conic, truncated at summit, closed at base by the adhering testaceous lamina ; aperture sub- triangular or elliptical. Operculum interior, quadrivalve ; valves movable. B. angulosus, sulcatus, tintinnabulum, nigrescens, cylin- draceus, calycularis, roseus, ovularis, miser, amphimorphus, perforates, laevis, spinosus, radiatus, palmatus, stalactiferus, plicatus, duplocomus, patellaris, semiplicatus, galeatus, sub- imbricatus, rugosus, plancianus, pustularis, crispatus, punc- tatus, fistulosus, latus — geniculatus. ACASTA. Shell sessile, ovate, subconic, com- posed of separable pieces ; cone formed of six equal, adnate, lateral valves, having an orbi- cular plate at base, internally concave, resem- bling a patella or basin. Operculum four valved. A. montagui, glans, sulcata. CREUSIA. Shell sessile, fixed, orbicular, con- vexo-conic, quadrivalve ; valves unequal, ad- 8 , GENERA OF SHELLS. nate, with distinct sutures. Operculum inte- rior, bivalve. C. stomia, spinulosa, verruca. PYRGOMA. Shell sessile, univalve, globose, ventricose, convex above, perforated at summit, aperture small, elliptical. Operculum bivalve; P. cancellata. ORDER II. — P^DUNCULATED CIRRHIPEDA. Body supported by a coriaceous, movable, tubular pedun- cle, the base of which is fixed to marine substances. Shell composed of contiguous pieces. ANATIFERA. Shell compressed at sides, five valved ; valves contiguous, unequal, lower one of the side valves largest. A. laevis, villosa, dentata, striata, vitrea. POLL.ICIPES. Shell compressed at sides, multivalve ; valves nearly contiguous, unequal, thirteen or more, lower one of the side valves smallest. P. cornucopia?, mitella, scalpellurn, villosus. Shell composed of distant pieces. CINERAS. Shell of five oblong, separate valves, not covering the body entirely, two at the aperture, the others dorsaL C. vittata. OTION. Shell of two small, semilunar, sepa- rate, testaceous valves, adhering laterally near the aperture. O. Cuvieri, Blainvillii. GENERA OF SHELLS. 9 CLASS XL — CONCHIFERA. Shell always bivalve, wholly or partly covering the animal ; sometimes free, sometimes fixed ; valves mostly joined at the margin by a hinge or ligament; the shell is sometimes enlarged by testaceous, accessory pieces, not belonging to the valves. ORDER L — CONCH. BIMUSCULOSA. Shell presenting in the interior two separate and lateral muscular impressions- SECTION I. — CONCH. CRASSIPEDA. Shell gaping at the sides when shut. TUBICOLARIA. Shell either contained in a testaceous tube, distinct from its valves, or encrusted, wholly or in part, in the parities of this tube, or projecting from it. The conchifera of this family are borers, and bury themselves in stones, wood and thick shells, but some remain in the sand. These, as well as the pholades, consist essentially of two similar, equal and regular valves, jointed like a hinge. In consequence of their having accessory pieces, but which do not properly belong to the valves, these shells have been mistaken for multivalves. ASPERGILLUM. Sheath tubular, testaceous, tapering and open anteriorly, and terminated posteriorly by an enlarged mass, presenting at one side the two valves imbedded in its pari- 10 GENERA OP SHELLS. etes ; terminal disc of the club convex, pierced by numerous sub-tubular holes, with a central fissure. It has been erroneously supposed that the asper- gillum is fixed to rocks by its smaller end, which is necessarily open. A. Javanum, vagi riife rum, NovaB Zelandise, agglutinans. CLAVIGELLA. Sheath tubular, testaceous, tapering and open anteriorly, and terminated posteriorly by an oval, subcompressed mass, bristled with spiniform tubes ; mass presenting at one side one valve imbedded in its parietes, the other free in the tube. C. cristala, echinata, tibialis, Brocchii. FISTULANA. Sheath tubular, generally tes- taceous, more turgid and closed posteriorly, attenuated anteriorly, open at summit, con- taining a free, bivalve shell ; valves equal and gaping when closed. F. cJava, corniformis, gregata, lagenula. SEPTARIA. Tube very long, gradually atten- uated at base, divided interiorly by vaulted par- titions, anterior extremity terminated by two other slender tubes, not divided interiorly. The septariaB are little more than large Fistulanre, and scarcely deserve to be made into a separate genus. S. arenaria. TEREDINA. Sheath testaceous, tubular, cyl- indrical, posterior extremity closed, presenting GENERA OF SHELLS. H the two valves of the shell ; anterior extremity open. T. personata, vacillum. TEREDO. Tube testaceous, cylindrical, tor- tuous, open at both extremities, independent of the shell, and covering the animal ; shell bivalve, situated posteriorly outside of the tube. The teredines do great mischief to ships, by boring their planks, &C. T. navalis, palmulatus. PHOLADARIA. Shell without a tubular sheath, having accessory pieces which do not belong to the valves, and gapes anteriorly ; liga- ment external. PHOLAS. Shell bivalve, equivalve, trans- verse, gaping at each side ; various accessory valves above or below the hinge ; inferior or posterior margin of the valves recurved out- wards. The additional valves are always smaller than the true valves, and must be considered as accessory, be- cause their number varies with the species. P. dactylus, orientalis, Candida, dactyloides, silicula, cos- tata, crispata, callosa, clavata, — oblongata, truncata, cunei- formis, pusillus. GASTROCHCENA. Shell bivalve, equivalve, subcuneiform, widely gaping ; anterior open- ing very large, oval, oblique ; the posterior 12 GENERA OF SHELLS. very slight. Hinge linear, marginal, without teeth. G. cuneiformis, mytiloides, modioJina. SOLENACEA. Shell without accessory pieces, and gaping only at the lateral extremities ; ligament external. The solenacea bury themselves in the sand, but do not perforate wood or stone. SOLEN. Shell bivalve, equivalve, elongated transversely, gaping at both ends, with small, inconspicuous beaks ; cardinal teeth small, va- riable in number, sometimes wanting, rarely diverging, more rarely received into grooves ; ligament external. S. vagina, corneus, vaginoides, siliqua, ensis, pygmaeus, ambiguus, cultellus, planus, minutus, legumen, Dombeii, Javanicus, Caribaeus, antiquatus, constrictus, coarctatus, stri- gilalus, radiatus, violaceus, rostratus, — costatus, centralis, viridis. PANOPJEA. Shell equivalve, transverse, une- qually gaping at the sides, a conic, cardinal tooth on each valve, and a compressed, short, ascending callosity by its side, not projecting outwards ; ligament exterior, on the longer side, fixed to the callosities. The Panopsea differs from the glycimeris, by having cardinal teeth, and by the ligament being on the long- est side ; from the solen by the greater projection of the beaks, and from mya by the ligament being ex- ternal. P. aldrovandi. GENERA OF SHELLS. 13 GLYCIMERIS. Shell transverse, widely gap- ing at each side ; hinge callous, toothless. Nymphse prominent ; ligament exterior. The glycimeris differs from solen and saxicava, by having the ligament on the shortest side, and also from solen, by having no cardinal tooth. G. siliqua. arctica. MYARIA. Ligament internal ; hazing one large spoon-shaped tooth in each valve, or in one only, to the cavity of which the liga- ment is attached. Shell gaping at one or both sides. MYA. Shell bivalve, transverse, gaping at both ends. Left valve with a large, com- pressed, rounded cardinal tooth, projecting almost vertically ; a cardinal fossa in the other valve ; ligament interior, inserted into the tooth and fossa of the opposite valves. M. truncata, arenaria, erodona, solemyalis, — acuta, mer- cenaria, hyalina. ANATINA. Shell transverse, subequivalve, gaping at one or both sides, cardinal tooth naked, dilated, spoon-shaped, projecting in- wardly, inserted on each valve, and receiving the ligament ; a lamina or falciform rib adnate and running obliquely below the cardinal teeth in most. Anatina differs from my a, by having two spoon- shaped teeth, instead of one. A. laterna, truncata, subrostrata, longirostris, globulosa, trapezoides, rugosa, imperfecta, myalis, rupicola — papy- ratia, Leana. 14 GENERA OF SHELLS. SECT. II. — CONCH1FERA TENUIPEDA. Lateral gaping inconsiderable. Div. I. — LIGAMENT INTERNAL, WITH OR WITHOUT AN EXTERNAL LIGAMENT. MACTRACEA. Shell equivalve, mostly gaping at the lateral extremities ; lig- ament internal, with or without an external one. I. LIGAMENT ALWAYS INTERNAL. (1.) Shells gaping at the sides. LUTRARIA. Shell inequilateral, transversely oblong or rounded, gaping at the lateral ex- tremities ; hinge with one tooth plaited to resemble two, or two teeth, one simple, with an adjacent deltoid-oblique pit projecting in- wards ; lateral teeth none ; ligament interior, fixed in the cardinal pits. Lutraria is distinguished from mactra, by having no lateral teeth. (a.) Shell transversely oblong. L. solenoides,. eUiptica, rugosa, lineata. (b.) Shell orbicular and subtriangular. L. compressa, piperita, tellinoides, Candida, papyracea,, plicatella, crassiplica, — eanaliculata. MACTRA. Shell transverse, inequilateral, subtriangular, gaping a little at the sides, beaks prominent ; cardinal tooth on each valve com- pressed, grooved, with a projecting fossa adja- cent ; two lateral teeth near the hinge, com- pressed, entering ; ligament interior, inserted into the cardinal fossa. GENERA OF SHE'ULS.. 15 If the pit be very large, the cardinal tooth is very oblique, short, and often partly obliterated ; but the lateral teeth always exist. M. gigantea, spengleri, striatella, carinata, helvacea, gran- dis, stultorum, maculosa, straminea, australis, violacea, fas- eiata, turgida, plicataria, rufescens, maeulata, subplicata, iriangularis, lactea, abbreviata, ovalina, alba, solida, cas- tanea, rufa, squalida, Brasiliana, donacia^ depressa, lilacea, trigonella, deltoides, crassatella, — similis, laleralis, oblonga, solidissima, arctata, tellinoides, nucleus. (2.) Shell not gaping at sides. CRASSATELLA. Shell inequilateral, subor- bicular or transverse, closed ; cardinal teeth two, subdivergent, with a lateral pit ; ligament interior inserted into the pit of each valve ; lateral teeth wanting or obsolete. Crassatella is distinguished from mactra and lutraria by the valves, when shut, being quite close on both sides. In a few species, the ligament appears a little on the outside. They are all sea shells, and generally become very thick by age. C. kingicola, donacina, sulcata, rostrata, glabrata, subra- diata, contraria, cuneata, erycinaea, cycladea, striata. ERYCINA. Shell transverse, subinequilateral, equivalve, rarely gaping ; cardinal teeth two, unequal, diverging, having a pit interposed ; lateral teeth two, oblong, compressed, short, entering ; ligament interior, fixed to the pit. One of the cardinal teeth joining the base of the lateral tooth, has been sometimes mistaken for a bifid tooth ; but the corresponding hollow on the opposite valvevshows that idea to be erroneous. E. cardioides — striata. 16 GENERA OF SHELLS. II. LIGAMENT APPEARING OUTSIDE ; OR, BEING DOUBLE, HAS ONE INTERNAL, AND THE OTHER EXTERNAL. UNGULINA. Shell longitudinal, or subtrans- verse, rounded above, subequilateral ; valves closed, beaks decorticated, a short, sub-bifid cardinal tooth in each valve, with an oblong marginal pit adjacent, contracted in the mid- dle ; ligament interior, inserted in the pits. The ungulinee are furrowed externally, and tinged red on the inside. U. oblonga, transversa. SOLENOMYA. Shell inequilateral, equivalve, transversely oblong, obtuse at. extremities ; margined by a projecting, shining epidermis, beak not prominent, scarcely distinct; a dila- ted, compressed, very oblique cardinal tooth in each valve, slightly concave above, receiv- ing the ligament ; ligament partly interior and partly exterior. The solenomyae resemble the mya at first sight, but are allied by their characters to the solen, and still more to the anatina. They are thin shells, almost cylindrical, with diverging rays from the beaks to the border and extremities of the valves. S. australis, mediterranea, — velum. AMPHIDESMA. Shell transverse, inequilate- ral, suboval or rounded, sometimes a little gap- ing at sides. Hinge with one or two Jeeth, and a narrow fossa for the interior ligament ; liga- ment double ; one exterior, short, and one in- GENERA OF SHELLS. 17 terior, fixed in the cardinal fossa ; sometimes there are more or less prominent lateral teeth ; the shells are generally small. A. variegata, donacilla, lactea, cornea, albella, lucinalis, Boysii, tenuis, flexuosa, prismatica, phaseolina, corbuloides, glabrella, purpurascens, nucleola, physoides, reticulata, transversum, orbiculata, equalis, punctata, radiata, lepida. CORBULEA. Shell inequivalve ; ligament interior. CORBULA. Shell regular, inequivalve, ine- quilateral, gaping none, or very little. A conic, curved, ascending cardinal tooth on each valve, and a lateral fossa ; no lateral teeth ; ligament interior, fixed in the fossa. The corbulse are distinguished from the ungulinao and crassatelJae by the inequality of their valves, and by the strong, prominent cardinal tooth, which charac- terises them. C. australis, sulcata, erythrodon, ovalina, taitensis, nucleus, impressa, porcina, semen, — contracta. PANDORA. Shell regular, inequivalve, ine- quilateral, transversely oblong, superior valve flattened, inferior convex ; two oblong, diverg- ing, unequal cardinal teeth in the upper valve; two oblong depressions on the other ; ligament interior. The pandora is distinguished from placuna by hav- ing two muscular impressions, and from the chamacea by the shell being regular and free. P. rostrata, obtusa, — trilineata. 2 18 GENERA OF SHELLS. LITHOPHAGA. Boring shells, without accessory pieces or sheath, and more or less gaping at their anterior side ; ligament exterior. SAXICAVA. Shell bivalve, transverse, ine- quilateral, gaping anteriorly and at the supe- rior margin. Hinge nearly toothless ; ligament exterior. Sometimes the hinge has two distant, scarcely denti- form tuberosities. The shells are short and obtuse posteriorly, anteriorly longer, flatter, and often trun- cated. They are small or of moderate size. S. rugosa, gallicana, pholadis, australis, veneriformis, distorta. PETRICOLA. Shell bivalve, subtriangular, transverse, inequilateral, rounded posteriorly ; the anterior edge sharp, slightly gaping. Hinge with two teeth in each valve, or in one only. P. lamellosa, ochroleuca, semilamellata, lucinalis, striata, costellata, roccellaria, exilis, ruperella, chamoides, pholadi- formis, fabagella, linguatula, fomicata. VENERUPIS. Shell transverse, inequilateral, posterior side very short, anterior slightly gap- ing. Hinge with two teeth on the right valve, and three on the left, sometimes three on each ; teeth small, approximate, parallel, slightly diver- gent ; ligament exterior. The hinge of venerupis appears analogous to that of venus, but it is distinguished by the cardinal teeth. They are perforating shells, and differ from the petri- colse by having three cardinal teeth, at least on one valve. GENERA OF SHELLS. 19 V. perforans, nucleus, irus, exotica, distans, crenata, car- ditoides. NYMPHACEA. Two or more cardinal teeth on the same valve ; shell often gaping slightly at lateral extremities ; ligament exterior ; nymphce generally projecting outside. NYMPHACEA SOLENARIA. SANGUINOLARIA. Shell transverse, subellip- tic, slightly gaping at lateral extremities, supe- rior edge arcuated, not parallel to the inferior. Hinge with two approximate teeth on each valve. The sanguinolaria is distinguished from solen, by the superior margin not being parallel to the inferior ; they also gape but little at the lateral extremities. S.X)ccidens, rosea, livida, rugosa. PSAMMOBIA. Shell transverse, elliptic or oval oblong, nearly flat, slightly gaping at each side, beaks prominent. Hinge with two teeth on the left valve, and one fitting between them on the opposite valve. The psammobiae approach in form nearer to tellina than to solen ; but besides gaping at the sides, they have not the irregular fold of the former, though they fre- quently have an angle or fold of the same form, on the anterior side of both valves. P. virgata, feroensis, vespertina, florida, maculosa, caeru- lescens, elongata, flavicans, squamosa, alba, Cayennensis, laevigata, tellinella, pulchella, aurantia, fragilis, livida, gala- thsea, lusoria, fusca. PSAMMOTEA. Shell transverse, oval or ob- 20 GENERA OF SHELLS. long oval, slightly gaping at sides ; a cardinal tooth in each valve, sometimes only in one. The psamrnoteae are merely degenerated psammobiae, differing merely in having only one cardinal tooth on the left valve ; or sometimes one valve has no teeth, and the other two. They have not the form of the solen, and their beaks are prominent, and they are destitute of the irregular fold of the tellina. P. violacea, zonalis, solenoides, pellucida, serotina, Can- dida, tarentina, donacina, variegata. NYMPHACEA TELLINARIA. I. HAVING ONE OR MORE LATERAL TEETH. TELLINA. Shell transverse or orbicular, gen- erally flattened ; anterior side angular, margin inflexed, or presenting at the edge a flexuous and irregular fold ; one or two cardinal teeth on the same valve ; two lateral teeth, often re- mote. The tellinae are readily known by the flexuous fold near the short side on their superior margin ; almost all of them have also lateral teeth, which are flattened on one valve. They are marine shore shells, slightly or not at all gaping at the sides, often smooth, some- times scaly, and in general adorned with lively colors. In the tellina, as well as the donax and capsa, the ligament is on the shorter side, and is wholly external. The valves of the same shell, though equal in contour, are not perfectly similar ; sometimes one is more pro- tuberant than the other, and sometimes the striae of one valve, or of one of its sides, are not like those on the other. (a. oblong.) T. radiata, unimaculata, semizonalis, macu- GENERA OF SHELLS. 21 losa, virgata, staurella, crucigera, Spengleri, rostrata, lati- rostra, sulphurea, foliacea, operculata, rosea, chloroleuca, elliptica, albinella, margaritina, strigosa, planata, punicea, depressa, pulchella, fabula, tenuis, exilis, donacina, nitida, scalaris, psammotella, — alternata, punicea, polita, iris, tenera, intastriata, lateralis, decora. (b. orbicular or round-oval.) T. remies, sulcata, striatula, scobinata, crassa, Ia3yigata; linguafelis, rugosa, lacunosa, gar- gadia, pristis, multangula, polygona, capsoides, decussata, Brasiliana, obliqua, umbonellaj deltoidalis, nymphalis, soli- dula, bimaculata, sexradiata, ostracea, — flexuosa. TELLENIDES. Shell transverse, inequilate- ral, somewhat flattened, gaping a little at the sides ; beaks small, depressed, margin without an irregular fold. Hinge with two diverging teeth on each valve ; lateral teeth two, subob- solete, the posterior approximated to the car- dinal in one valve. The tellenides differs from psammobia by having lateral teeth, from tell in a, by wanting the flexuous mar- ginal fold, and from lucina by its gaping, and not hav- ing the internal fascial impressions. T. Timorensis — rosea. CORBIS. Shell transverse, equivalve, with- out an irregular fold at the anterior margin ; beaks curved inwards ; two cardinal teeth ; two lateral, the posterior nearest the hinge ; muscular impressions simple. The corbis is principally distinguished from the lucina by the animal inhabiting it, and by not having one of the muscular impressions lengthened into •» 22 GENERA OF SHELLS. band, and from tellina, by wanting the irregular fold on the anterior margin. C. fimbriata — (Fossil) lamellosa, petunculus. LUCINA. Shell suborbicular, inequilateral, beaks small, pointed oblique. Hinge variable ; two cardinal teeth, of which one is bifid, dis- appearing by age ; two lateral teeth, the pos- terior nearest the cardinal ; two muscular im- pressions distant, the posterior produced into a long band ; ligament exterior. L. Jamaicensis, Pennsylvania, edentula, mutabilis, radula, concentrica, divaricata, carnaria, scabra, reticulata, squamosa, lactea, undata, circinaria, columbella, sinuata, pecten, lutea, digitalis, globularis. DONAX. Shell transverse, equivalve, inequi- lateral, anterior side very short, very obtuse ; two cardinal teeth, either on one or both valves ; one or two lateral teeth, more or less remote ; ligament exterior, short, in the place of the lunule. This genus is characterised by its rather flattened and almost triangular shell, and by having one or two rather distant lateral teeth, separated from the cardinal teeth, and analogous to the lateral teeth of lucina, corbis, cyclas, mactra and tellina. They are marine shore shells, smooth or finely striated, and often deco- rated with lively colors. (a.) Internal margin entire, or nearly so. D. scortum, pubescens, cuneata, compressa, radians, abbre^ viata, granosa, columbella,veneriformis, australis, epidermia bicolor, vittata, triquetra. GENERA OF SHELLS. 23 (b.) Internal margin crenulated or toothed. D. ringens, rugosa, Caienensis, elongata, denticulata, car- dioides, meroe, scripta, trunculus, fabagella, anatinum, mar- tinicensis, variabilis, fossor. II. HAVING NO LATERAL TEETH. CAPSA. Shell transverse, equivalve, closed. Hinge with two teeth in the right valve, em- bracing a bifid tooth in the other ; lateral teeth none; ligament exterior, on the short side. The capsse are rather inequilateral shells, allied to the psammobiae and certain tellinaa by their cardinal teeth, but they scarcely gape at the side, and have not the flexuous fold of tellina. C. laBvigala, Brasiliensis. CRASSINA. Shell suborbicular, transverse, equivalve, sub-inequilateral, closed. Hinge with two strong diverging teeth on the right valve, and two very unequal teeth on the other ; lig- ament exterior, on the longer side. The crassina resembles a small crassatella in appear- ance, solidity and perfect closeness when shut, but dif- fers in the position of the ligament. It differs from venus by having only two teeth on each valve, those of the left appearing almost like a single tooth, one of them being large, and the other but very slightly prom- inent. C. Danmoniensis. 24 GENERA OF SHELLS. SECT. III. — CONCHIFERA LAMELLIPODA. CONCKLE. Three cardinal teeth, at least, in one valve ; as many or fewer in the other ', sometimes lateral teeth. The conchaB constitute one of the most beautiful and numerous families of the conchifera. Their shells are equivalve, orbicular or transverse, always regular, free, and in general very close, especially at the sides. They are more or less inequilateral, and seldom have true, radiating ribs. CONCHJE FLUVIATILES. Like the naiadae, these shells are covered with a kind of greenish epidermis, which turns more or less brown, and is often decorticated at the beaks. They are distin- guished from them by the hinge, which has cardinal teeth, like the venus, near the hinge. CYCLAS. Shell ovate-globose, transverse, equivalve ; beaks protuberant, cardinal teeth very small, sometimes nearly obsolete ; some- times two on each valve, one of which is folded, sometimes only one, plaited or lobed on one valve, and two on the other ; lateral teeth transversely elongated, compressed, lamelli- form; ligament exterior. The cyclades are small shells, with thin valves, and never have three teeth on either. The beaks are never eroded. They are grayish green or yellowish : some smooth, others transversely striated with lightish col- ored bands. C. rivicola, cornea, lacustris, obliqua, calyculata, obtusalis, GEN ERA OF SHELLS. 25 fontinalis, australis, sulcata, striatina, Saratogea, — rhom- boidea, partumeia. CYRENA. Shell rounded, triangular, turgid or ventricose, solid, inequilateral, covered by an epidermis, beaks decorticated. Hinge with three teeth on each valve ; lateral teeth gener- ally two, one of which is near the cardinal ; ligament exterior, on the widest side. The cyrense are generally thick and rather large, shell always covered with a greenish or brown epi- dermis. They are distinguished from cyclas by hav- ing three cardinal teeth in each valve. They have also lateral teeth, one of which is often placed below the corselet. (a.) Lateral teeth serrate or dentate. C. trigonella, orientalis, cor, fuscata, fluminea, truncata, violacea. (b.) Lateral teeth entire. C. depressa, Caroliniensis, Bengalensis, Zeylanica. GALATHEA. Shell equivalve, subtriangular, covered by a greenish epidermis ; cardinal teeth sulcated, two on the right valve, connivant at base; three on the other, the intermediate one advanced, distinct ; lateral teeth remote ; ligament exterior, short, prominent, turgid ; nymphae prominent. The galathea is distinguished from cyrena by the peculiar form of its cardinal teeth. The muscular impressions are lateral, and appear double on each side. G. radiata. 26 GENERA OF SHELLS. CONCHA MARINE. Mostly no lateral teeth ; shell sometimes covered with an epi- dermis, except at the leaks. CYPRINA. Shell equivalve, inequilateral, obliquely cordate ; beaks obliquely curved. Hinge with three unequal teeth, approximated at base, subdivaricate superiorly ; a lateral tooth, distant from the hinge, on the anterior side, sometimes obsolete ; nymphaeal callosi- ties large, arcuated, terminated near the beaks by a pit ; ligament exterior, partly under the beaks. The cyprinse are in general rather large shells, very like the veneres, and chiefly distinguished by having a compressed lateral tooth on the anterior side ; by their large nymphre, generally terminated by an oval pit, sometimes singularly large near the beaks ; by the ligament extending under the beaks, and there filling up the terminal pit of the nymphse, and by having an epidermis. C. gigas, Islandica,Pedomontana, tenui-stria. CYTHEREA. Shell equivalve, inequilateral, suborbicular, triangular or transverse. Hinge of the right valve four toothed, three of which are divergent and approximate at base, the other solitary, under the lunule. The other valve with three diverging teeth, approximate at base, with a remotish pit, parallel to the margin ; lateral teeth none. GENERA OF SHELLS. £7 The cythefea is distinguished from the verms by having four cardinal teeth on one valve, and three teeth and the pit on the other. They are all sea shells, solid, in general variously and beautifully colored, free, with the beaks curved and moderately prominent. The Oval pit on the left valve corresponds to the insulated tooth of the right. I. INTERNAL MARGIN OF THE VALVES VERY ENTIRE. (a.) interior cardinal tooth, with a striated canal or dentated border. C. lusoria, petechialis, irnpudica, castanea, zonaria, mere- trix, graphica, morphina, purpurata, casta, corbicula, tripla, — convexa. (6.) Anterior cardinal tooth without striated canal or dentated border. C. gigantea, erycina, lilacina, impar, erycinella, pecto- ralis, planatella, florida, nitidula, chione, maculata, citrina, albina, laeta, mactroides, trigonella, sulcatina, hebreea, cas- trensis, ornata, picta, tigrina, venetiana, juvenilis, rufa, guine- ensis, dione, arabica, trimaculata, immaculata, pellucida, hepatica, lucinalis, lunaris, lactea, exoleta, lincta, concen- trica, prostrata, interrupta, tigerina, punctata, urnbonella, undatina, scripta, nummulina, muscaria, pulicaris, mixta, abbreviata, — occulta. II. INTERNAL MARGIN OF THE VALVES CRENATED OR DEN- TATED. C. pectinata, gibba, ranella, divaricata, testudinalis, cune- ata, placunella, rugifera, plicatina, flexuosa, rnacrodon, lunu- laris, squamosa, cardilla, cygnus, dentaria. VENUS. Shell equivalve, inequilateral, trans- verse, or suborbicular. Hinge with three ap- proximate teeth in each valve, the lateral ones diverging at summit ; ligament exterior, cover* ing the labia. 28 GENERA OF SHELLS. The veneres are amongst the most beautiful of the conchiferae. They are not distinguished by their gen- eral form from the cytherese, but are more commonly transverse than orbicular. The middle cardinal tooth, which is often bifid, is straight, whilst the lateral are v oblique and diverging ; a few species have all the car- dinal teeth straight. They are found in all seas, and live in the sand, a short distance from the shore. I. INTERNAL MARGIN OF THE VALVES CRENATED OR DEN- TATED. (a.) Shells with lamellar stria. V. puerpura, reticulata, pygmaea, corbis, crenulata, dis- cina, verrucosa, rugosa, casina, crebrisulca. plicata, cancel- lata, subrostrata, — castanea. inequalis, elevata, praeparca. (6.) Shells without lamellar strife. V. granulata, pectorina, marica, cingulata, cardioides, grisea, elliptica, Dombeii, mercenaria, lagopus, gallina, gal- linula, pectinula, sulcata. II. INTERNAL MARGIN OF THE VALVES VERY ENTIRE. V. lamellata, exalbida, rufa, dorsata, hiantina, crassisulca, corrugata, Malabarica, papilionacea, adspersa, punctifera, turgida, litterata, sulcaria, textile, texturata, geographica, rariflamma, decussata, pallastra, glandina, truncata, retifera, anomala, galactites, exilis, scalarina, Scotica, aurea, vir- ginea, marmorata, ovulea, ]aterisulca, callipyga, opima, nebu- losa, phaseolina, carneola, florida, petalina, bicolor, flori- della, catenifera, pulchella, sinuosa, tristis, rimularis, vul- vina, veVmiculosa, flammiculata, conularis, strigosa, apbro- diaa, Peronii, aphrodinoides, elegaritina, flammea, undulosa, pumila, ovata, inquinata — grata, notata. VENERICARDIA. Shell equivalve, inequila- teral, suborbicular, generally with longitudinal radiating ribs ; cardinal teeth two, oblique, in- clining to the same side. GENERA OF SHELLS. 29 The venericardiae seem to connect the conchae with the cardiacea ; their radiating ribs give them perfectly the appearance of cardium, and the hinge would re- semble the venus if it had a third diverging tooth on each valve. It appears to differ from cardita merely by wanting the lunular tooth, two oblique teeth repre- senting the lateral tooth of cardita, which is always channelled. They are chiefly fossil. V. planicosta, petuncularis, imbricata,australis, acuticosta, mitis, senilis, laBvicosta, concentrica, decussata, elegans — tridentata. CARDIACEA. Cardinal teeth irregular, either in their form or situation ; or generally accompanied by one or two lateral teeth. The cardiacea are ventricose shells ; almost all are furnished with radiating, longitudinal ribs, and when viewed at the fore part are heart shaped. They are equi valve, regular, and sometimes gaping. CARDIUM. Shell equivalve, subcordiform, beaks protuberant, valves dentated or plaited on the internal edge. Hinge with four teeth on each valve, the two cardinal approximate and oblique, the two lateral articulating crosswise with their opponents ; two lateral, remote, en- tering. The prominent, cordate beaks of this genus, are very remarkable. The convex side of the valves is gen- erally furnished with longitudinal ribs, more or less prominent, frequently striated, imbricate or spinous; but the interior is smooth, and only furrowed towards the margin. The ligament is external and very short; there are two, faint, muscular impressions. They are 30 GENERA OF SHELLS. found in all seas, and generally live buried in the sand near the coasts. (a.) JY0 particular angle on the beaks, and the anterior side at least as large as th& posterior. C. costatum, Indicurn, ringens, Asiaticum, lenuicostatum, fimbriatum, Brasilianum, apertum^ papyraceum, bullatum, ciliare, echinatum, pseudolhna, aeuleatum, erinaceum, tuber- culatum, isocardia, muricatum, angulatum, marmoreum, elongatum, ventricosum, rugosum, sulcatum, serratum, laevi- gatum, biradiatum, aBolicum, pectinatum, rusticum, edule, Groenlandicum, latum, crenulatum, exiguum, rninutum, roseum, scobinatum, — Mortoni, pinnulatum. (b.) Beaks carinated, or having an angle; posterior side often larger than the anterior. C. unedo, medium, fragum, retusum, tumoriferurn, hemi- cardium, cardissa, inversum, Junonias, lineatum. CARDITA. Shell, free, regular, equivalve, inequilateral. Hinge with two unequal teeth ; one short, straight, under the beaks, the other oblique, marginal, prolonged under the corse- let. The carditae may be easily confounded with the venericardise, if sufficient attention be not paid to the direction of the two teeth, which in the latter are both oblique and turned to the same side, which is not the case in cardita. They differ from chama in not being inequivalve, or irregular, nor ever fixed by the lower valve to marine substances. Some species are said to fix themselves .by a sort of byssus, like the area and mytilus. (a.) Shell subcordatc or oval, more transverse than longi- tudinal. C. sulcata, ajar, turgida, squamosa, gallicana, intermedia, rudista, Etrusca, tarpezia, bicolor, depressa. GENERA OF SHELLS. 31 (b.) Shell more longitudinal than transverse. C. phrenitica, crassicosta, rufescens, calyculata, subaspera, nodulosa, sinuata, concamerata, aviculina, citrina, sublaevi- gata, corbularis, lithophagella, crassa. CYPRICARDIA. Shell free, equivalve, inequi- lateral, obliquely or transversely elongated. Hinge with three teeth beneath the beaks, and a lateral tooth prolonged under the corse- let. The cypricardiae differ from the carditse, which they resemble in general form, by having, like the venus, three teeth, instead of one only, under the beaks. C. Guiniaca, angulata, rostrata, corralliophaga. HIATELLA. Shell equivalve, very inequila- teral, transverse ; gaping at the superior mar- gin. Hinge with a small tooth on the right valve, and two oblique teeth, somewhat longer, on the left ; ligament exterior. H. arctica. ISOCARDIA. Shell equivalve, heart shaped, cordate, ventricose ; beaks distant, diverging, rolled spirally to one side ; cardinal teeth two, compressed, entering, one of which is curved and sunk under the beak ; lateral tooth elon- gate, under the corselet ; ligament exterior, forked on one side. I. cor, arietina, Moltkiana, semisulcata. 32 GENERA OF SHELLS. ARCACEA. Cardinal teeth small, numerous, entering, disposed in each valve in a straight, arched or broken line. The arcacea are very remarkable by the hinge of their shells, which are equivalve, regular, the beaks commonly distant, the ligament entirely external, and the muscular impressions lateral. Several have a vel- vety epidermis ; some adhere to rocks by tendinous threads, and the shell gapes more or less at the supe- rior margin. They are all sea shells, and live near the shore. CUCULLJEA. Shell equivalve, inequilateral, trapeziform, ventricose ; beaks distant, separa- ted by the facet of the ligament ; anterior muscular impression, with an angular or auri- cular margin. Hinge linear, straight, with minute transverse teeth ; having at each ex- tremity, two to five ribs parallel to it ; liga- ment entirely exterior. The cuculla?a are large, very tumid shells, with the anterior side obliquely truncated, forming a broad, cor- date, flattened corselet, slightly elevated towards the middle. The hinge is that of the area, but as the shell grows old, it is displaced, and leaving the remains of its former margins at the extremities, gives rise to two parallel ribs by which it is terminated, which is not seen in the area. C. auriculifera, crassatina. ARCA^ Shell transverse, subequivalve, ine- quilateral, beaks distant, separated by the area GENERA OP SHELLS. 33 of the ligament. Hinge linear, straight, with- out ribs at the extremities ; teeth numerous, crowded, alternately inserted into each other ; ligament exterior. The area is readily known by the peculiar form of its hinge. When placed on the superior margin, they resemble a boat, whence their name. They often gape at the superior margin, in consequence of the tendinous fibres which the animal puts out to fix himself to the rocks. The space between the beaks forms a rhom- boidal flat, or sometimes a hollow facet, marked with furrows, which receives the ligament. (a.) Superior margin not crenulated within. A. tortuosa, semitorta, Nose, tetragona, umbonata, sinuata, avellana, cardissa, ventricosa, retusa, sulcata, ovata, barbata, fusca, Magellanica, Domingensis, lactea, trapezina, pista- chia, pisolana, cancellaria,callifera, irudina. (&.) Superior margin crenulated, loithin. A. Kelbingii, scapha, antiquata, rhombea, granosa, auric- ulata, inaequivalvis, Indica, senilis, Brasiliana, corbicula, squamosa, Cayenensis, bisulcata — staminea, lienosa, pon- derosa, pexata, incongrua, transversa. PECTUNCULUS. Shell orbicular, nearly lentic- ular, equivalve, subequilateral, closed. Hinge arcuated with numerous oblique, uniformly arranged, alternately inserted teeth ; those in the middle obsolete, almost wanting ; ligament exterior. The pectunculi are distinguished from the area by the orbicular form of the shells, and especially by the arched hinge; the teeth are less numerous, farther apart and larger, and they never gape. The beaks are 3 34 GENERA OF SHELLS. not very distant, yet are always separated by a narrow, furrowed, rather hollow facet, to which the ligament is attached, and which distinguishes them from the nu- culse. The shells are all marine, and resemble the pectines by their form, and by the internal margin being always crenate. Many species acquire consid- erable thickness by age, and such a change of form as renders it difficult to distinguish them. (a.) Distant, longitudinal furrows, and frequently fine trans- verse or longitudinal stria. P. glycimeris, pilosus, undulatus, marmoratus, scriptus, pennaceus, rubens, angulatus, stellatus, pallens, violaces- cens, zonalis, striatularis, nummarius. (b.) Prominent and radiating longitudinal ribs, with or with- out transverse strice. P. castaneus, pectiniformis, pectinatus, radians, vitreus. NUCULA. Shell transverse, ovate triangular, or oblong, equivalve, inequilateral ; no area between the beaks. Hinge linear, broken, many toothed, interrupted in the middle by an oblique, spoon-shaped pit ; teeth numer- ous, subacute, often produced as in the pec- ten ; beaks contiguous, curved backwards ; ligament marginal, partly inferior, inserted into the cardinal fossa, or pit. The nuculus is distinguished from the pectunculus and area, not only by the broken, angular line of their hinge, but also by the ligament, which is partly inter- nal, and by wanting the facet between the beaks. They are small sea shells, somewhat triangular, and more or less pearly on the inside, N. lanceolata. rostrata, pella, Nicobarica, obliqua, marga- jitacea — limatula, proxima, nucleus, recurva. GENERA OF SHELLS. 35 t TRIGONIANA. Cardinal teeth lamellar, transversely, striated. The teeth of the trigoniana differ from those of the arcacea by the stria? being on separate laminaB, instead of being on the hinge itself. TRIG ONI A. Shell equivalve, inequilateral, triangular, sometimes suborbicular. Cardinal teeth oblong, flattened at the sides, divergent, furrowed transversely ; two are on the right valve, furrowed on both sides, and four on the other, furrowed on one side only ; ligament exterior, marginal. The trigonise are regular, free, very inequilateral sea shells, and all, except one species, only known in a fossil state, fourteen of which are enumerated. T. pectinata. CAST ALIA. Shell equivalve, inequilateral, triangular; beaks decorticated, recurved pos- teriorly. Hinge with two lamellar teeth, stria- ted transversely ; one posterior, remote, abbre- viated, sub-trilamellate, the other anterior, elongated, lateral ; ligament exterior. The castalia resembles a trigonia in appearance, but differs from it in the number and situation of its teeth, which have more resemblance to those of the unio, between which and the trigonia it seems to be inter- mediate. It appears to be a river shell. C. ambigua. 36 GENERA OF SHELLS. NAIADA. Fresh water shells, the hinge of which is sometimes furnished with an irregular., simple, or divided cardinal tooth, and a longitudinal one, which extends under the corselet ; some- times no tooth, or furnished with irregular, granular tuber- cles throughout ; muscular impression posterior, compound; beaks decorticated, often eroded. The naiada are well distinguished from the fresh water conchse by their hinge and inhabitant. The shell is free, regular, equivalve, inequilateral, always transverse ; the epidermis is greenish, inclining to brown, and always wanting at the beak. The mus- cular impressions are. lateral and quite separate ; that of the posterior side is composed of two or three dis- tinct, unequal impressions, which distinguishes them from the other bimuscular conchifera. UNIO. Shell transverse, equivalve, inequi- lateral, free ; beaks decorticated, suberoded ; muscular impression posterior, compound ; hinge with two teeth on each valve ; one car- dinal, short, irregular, simple or bipartite, sub- striated, the other elongated, compressed, late- ral, prolonged under the corselet ; ligament external. The unio is very distinct from the anodonta, which it resembles in shape, by its hinge. Each valve has a short cardinal tooth, that on the left generally simple, that on the right divided into two lobes, besides a late- ral tooth. The two teeth articulate together when the valves are shut. The shell is generally formed of a very brilliant mother of pearl. The lamina of the margin of the shell, above the lateral tooth, has a trun- GENERA OF SHELLS. 37 cation or sinus, which seems to receive a portion of the ligament. (a.) Cardinal tooth short, thick, not crested, and substriated. U. sinuala, elongata, crassidens, Peruviana, rariplicata, purpurata, ligamentina, obliqua, retusa, rarisulcata, coarc- tata, purpurascens, brevialis, rhombula, carinifera, georgina, clava, recta, naviformis, glabrata, rotundata, littoralis, semi- rugata, nana, delodonta, sulcidens. (b.) Cardinal teeth short, compressed, raised, and often crested. U. rostrata, pictorum, Batava, corrugata, nodulosa, vari- cosa, granosa, depressa, Virginiana, luteola, marginalis, augusta, manca, spuria, australis, anodontina, suborbiculata. JV. American. U. ridibundus, monodonta, undulatus, abrup- tus,phaseolus, tetralasmus, dehiscens, interruptus, globulus, declivis, lapillus, camptodon, lugubris, radiatus, ovatus, cari- osus. nasutus, cylindricus, subtentus, plicatus, rectus, torsus, mytiloides, rnetanever, scalenius, cornutus, verrucosus, tuber- culatus, gibbosus, cuneatus, ventricosus, siliquoideus, trian- gularis, parvus, ^Esopus, calceolus, lanceolatus, donaci- formis, ellipsis, irroratus, lacrymosus, ater, rubiginosus, heterodon, sulcatus, planulatus, circulus, multiradiatus, occi- dens, securis, iris, zigzag, patulus. HYRIA. Shell equivalve, obliquely triangu- lar, eared, truncated at base, and straight. Hinge with two short teeth ; one posterior or cardinal, divided into numerous, diverging portions, the interior of which are smallest ; the other anterior or lateral, lamellar, very long ; ligament external, linear. The hyria is distinguished from the unio, by its gen- eral form, and by the cardinal tooth, particularly that of the right valve, which is divided into numerous lamel- 38 GENERA OP SHELLS. lar folds, the innermost very small, and has the appear- ance of a bundle of very unequal, diverging laminae. This compound tooth is rather depressed, and always inclines towards the posterior side of the shell, instead of rising perpendicularly to the plane of the valve. H. avicularis, corrugata.* ANODONTA. Shell equivalve, inequilateral, transverse. Hinge linear, toothless ; a cardi- nal lamina, smooth, adnate, truncated, or form- ing a sinus at its anterior extremity, termina- ting the base of the shell ; two muscular im- pressions, remote, lateral, subgeminate ; liga- ment external, linear, descending at its anterior extremity into the sinus of the cardinal lamina. The anodontae are fresh water shells, usually very thin, and often of a large size. They greatly resemble the unio, but have neither cardinal nor lateral tooth, the hinge presenting merely a smooth interior margin or laminae, situated immediately below the nymphse, and terminated anteriorly by a truncation or sinus. The shell is pearly, and covered with a thin, greenish, false epidermis ; beaks oblique, partly inclining to the posterior margin. * SYMPHYNOTA. — Say.- Shell fluviatile; bivalve 5 valves con- nate at the dorsal margin. S. laevissima, bialata, alata, complanata, compressa, gracilis, teuuis- sima, ochracea, cygnea. ALASMIDONTA. — Say. Shell transverse, equivalve; inequila- teral j hinge with a primary tooth in each valve j cicatrices three. It is separated from anodonta by its primary tooth, and from unio; by being destitute of the lamelliform teeth. A. undulata, marginata, ambigua, confragosa. GENERA OF SHELLS. 39 (a.) JV0 distinct angle at the posterior extremity of the car* dinal line. A. cygnea, anatina, sulcata, fragilis, cataracta, rubens, crispata, uniopsis, Pennsylvanica, intermedia, suborbicu- lata. (b.) A distinct angle at the posterior extremity of the car- dinal line. A. trapezialis, exotica, glauca, sinuosa, Patagonica. IRIDINA. Shell equivalve, inequilateral, trans- verse ; beaks small, recurved, almost straight ; muscular impressions as in anodonta. Hinge long, linear, attenuated at the middle, tuber- cular, almost crenulate throughout ; tubercles unequal, frequent ; ligament exterior, margi- nal. The principal difference between the anodonta and iridina, consists in the tuberculated hinge of the latter. The shell is rather thick, brilliant pearly, reddish, especially internally, and iridescent. I. exotica. CHAMACEA. Shell inequivalve, irregular, fixed; hinge with one thick tooth, or without teeth; two separate and lateral mus- cular impressions. The ligament is external, and sometimes sunk irreg- ularly towards the interior; the hinge is somewhat allied to the tridacnea. The shells are often lamellar and spinous, their beaks always irregular, sometimes large and contorted. They are attached to rocks, corals, and often to each other. DICERAS. Shell inequivalve, adherent ; nates conic, very large, divaricate, turned into 40 GENERA OF SHELLS. irregular spires ; tooth very large, thick, con- cave, sub-auricular, prominent in the largest valve ; two muscular impressions. The diceras somewhat resembles isocardium, but is more nearly allied to chama. It differs from them by its hinge, and the singular form of the beaks. Fossil. Fifty three species enumerated. CHAMA. Shell irregular, inequivalve, adhe- rent ; beaks incurved, unequal. Hinge with a single thick tooth, oblique, subcrenate, inserted into the fossa of the opposite valve ; two dis- tant, lateral muscular impressions ; ligament external, depressed. This genus now consists of irregular, coarse, rough, scaly, or spinous shells, with very unequal valves, and only one thick, oblique, transverse, callous tooth, usu~ ally crenate or furrowed. The beaks are curved in- wards, and only one of them projects at the base of the shell. They live in shallow water, attached by the lar- ger valve to rocks, corals, or to each other. They are seldom brilliantly colored. (a.) Beaks turning from left to right. C. lazarus, damaecornis, gryphoides, crenulata, unicornis ; florida, limbula, aeruginosa, asperella, decussata. (b.) Beaks turning from right to left. C. arcinella, radians, cristella, albida, ruderalis, croceata^ Japonica. ETHERIA. Shell irregular, inequivalve, adhe- rent ; beaks short, as it were sunk in the base of the valves. Hinge toothless, undate, sub- sinuate, unequal ; two distant, oblong, lateral GENERA OF SHELLS. 41 muscular impressions ; ligament external, tor- tuous, somewhat penetrating within the shell. The etherise are very rare shells, and little known,, being attached to rocks in deep water. They resemble ostrea3 in form, but are allied to the chamse by their muscular impressions, and are only distinguished from them by having no tooth at the hinge. They are rather large, and attached by the lower valve. (a.) An oblong callosity in the base of the shelL E. elliptica, trigonula. (b.) Without the callosity. E. semilunata, transversa. CONCHIFERA UNIMUSCULOSA. Shell presenting internally one muscular impression, nearly in the centre. SECT. I. — LIGAMENT MARGINAL, ELONGATED ON THE MARGIN, SUBLINEAR. TRTDACNEA. Shell transverse, equivalve, muscular impression under the middle of the superior margin, and produced to each side under it. The shells of this family are regular, solid, and re- markable by their sinuous or wavy superior margins. TRIDACNA, Shell regular, equivalve, ine- quilateral, transverse, gaping at the lunule. Hinge Avith two compressed, unequal, ad- vanced and entering teeth ; ligament mar- ginal, external. The tridacna is perfectly distinguished from hip- popus by the lunule being always open and gaping, through which the animal protrudes a byssus, by 42 GENERA OF SHELLS. which it is suspended to the rocks, however large and heavy it may be. The T. gigas is the largest shell known. The largest known is said to weigh five hundred pounds. T. gigas, elongata, squamosa, crocea, mutica, serrifera, pustulosa. HIPPOPUS. Shell equivalve, regular, ine- quilateral, transverse, closed at the lunule. Hinge with two compressed, unequal, anterior and entering teeth ; ligament marginal, ex- terior. The hippopus differs from tridacna by having the lunule shut ; wherefore it cannot fix itself to the rocks by a byssus, and consequently must have a different organization from that of the preceding genus. H. maculatus. MYTILACEA. Ligament at the hinge subinternal, marginal, linear, very entire, occupying a great part of the anterior margin; rarely foliated. MODIOLA. Shell subtransverse, equivalve, regular, posterior side very short ; beaks nearly lateral, depressed on the short side. Hinge toothless, lateral, linear ; ligament cardinal, mostly interior, received into a marginal groove ; muscular impression sublateral, elon- gated, securiform. The modiolse differ from the mytili in being rather transverse than longitudinal shells, the beaks not being truly terminal, the posterior side extending a little be- yond them ; moreover, they are rarely fixed by a GENERA OF SHELLS. 43 byssus. They usually gape a little at the middle of the contracted margin of the posterior side. M. papuana, tulipa, albicosta, Guyanensis, Adriatica, pulex, vagina, picta, sulcata, plicatula, sernifusca, securis, purpurata, barbata, discrepans, discors, trapesina, cinna- monea, silicula, plicata, semen, lithophaga, caudigera, — Americana, castanea. MYTILUS. Shell longitudinal, equivalve, regular, pointed at base, fixed by a byssus ; beaks nearly straight, terminal, pointed ; hinge lateral, generally toothless ; ligament marginal, subinterior ; muscular impression elongated, clavate, sublateral. The mytili are all sea shells, and are not foliated, nor gaping at the superior margin, in which they differ from the pinna, which they otherwise resemble, (a.) Shell with longitudinal furrows. M. magellanicus, erosus, crenatus, decussatus, hirsutus, exustus, bilocularis, ovalis, uslulatus, Domingensis, Sene- galensis, — bamatus, lateralis. (b.) Shell without longitudinal furrows. M. elongatus, latus, zonarius, canalis, ungulatus, viola- ceus, opalus, smaragdinus, perna, afer, acbatinus, unguiaris, planulatus, borealis, augustanus, corneus, Galloprovincialis, edulis, abbreviatus, retusus, hesperianus, incurvatus, line- atus, lacunatus, — cubitus, leucophaBatus. PINNA. Shell longitudinal, wedge shaped, equivalve, gaping at summit, pointed at base ; beaks straight. Hinge lateral, toothless ; lig- ament marginal, linear, very long, subin- terior. 44 GENERA OF SHELLS. The pinna? are all sea shells, generally very large, thin in proportion to their size, often brittle ; its frac- ture exhibits delicate transverse stria3 like gypsum. P. rudis, flabellum, semi-nuda, angustana, nobilis, squa- mosa, marginata, muricata, pectinata, saccata, varicosa, dol- abrata, ingens, vexillum, -nigrina, subquadrivalvis. MALLEACEA. Ligament marginal, sublinear, either interrupted ly crenu- lations or serial teeth, or wholly simple ; shell subincqui- valve, foliated. The mallacea differ from the mytilacea by the folia- ted texture of the shell, and by being irregular and in- equi valve. The ligament also is not perfectly internal. CRENATULA. Shell subequivalve, flattened, foliate, somewhat irregular ; no peculiar aper- ture for the byssus. Hinge lateral, linear, marginal, crenulate ; crenulations in regular series, callous, somewhat excavated, receiving the ligament. The hinge of the crenatula a good deal resembles that of the perna, but presents a row of callous and rather concave indentations, which receive the liga- ment, whereas the perna has a row of linear, parallel, truncated teeth, articulating with those of the opposite valve, the ligament being inserted in the interstices. The crenatulaB are rare shells, generally thin, some- times almost membranous and brittle. C. avicularis, modiolaris, nigrina, bicostalis, viridis, myti- loides, phasianoptera. PERNA. Shell subequivalve, flattened, some- what deformed, texture lamellar ; hinge linear, GENERA OP SHELLS. 45 marginal, composed of sulciform, transverse, parallel teeth, not opposed, between which the ligament is inserted ; a sinus for the byssus a little gaping under the end of the hinge ; parietes callous. The hinge of the perna differs from that of the area by the cardinal teeth of one valve not articulating with those of the other, but lying upon them when the valve is shut. The ligament is also differently situated. They more resemble crenatulae. They are sea shells, with small, nearly equal beaks, situated at one of the extre- mities of the hinge. P. ephippium, obliqua, isogonum, avicularis, femoralis;, eanina, marsupium, sulcata, vulsella, nucleus. MALLEUS. Shell subequivalve, rough, de- formed, generally elongated, sublobate at base ; beaks small, divergent. Hinge toothless ; an elongated conic groove, under the hinge, trav- ersing the area of the ligament obliquely ; lig- ament subexternal, short, received into the sloping area of each valve. The mallei are distinguished from the pernse by their hinge ; from the avicula? by the conical pit, below the beaks, and by the valves being, though irregular, of the same size, and having no sinus on the left valve. They are coarse, irregular shells, remarkable for their form, with little beauty externally, but are rather bril- liant pearly internally. M. albus, vulgaris, normalis, vulsatellus, anatinus, decur- talus. 46 GENERA OF SHELLS. AVICULA. Shell iriequivalve, fragile, rather smooth, base transverse, straight ; extremities produced, the anterior caudiform, or tail-like ; a notch in the left valve. Hinge linear, uni- dentate, beneath the beaks ; area of the liga- ment marginal, narrow, channelled, not trav- ersed by the byssus. When the valves are spread open, the shell has a rude resemhlance to the wing of a bird, whence its name. They are sea shells, generally smooth exter- nally, thin, and pearly within. Their beaks are oblique, small, and not prominent. A. macroptera, lotorium, semisagitta, heteroptera, fal- cata, crocea, Terentina, atlantica, squamulosa. papilionacea, physoides, virens, trigonata, phalaenacea, hirudo. MELEAGRINA. Shell subequivalve, rounded, quadrate, scaly externally ; inferior cardinal margin straight, not caudate anteriorly ; a sinus for the byssus at the posterior base of the valves ; left valve at this part narrow and emarginate. Hinge linear and toothless ; area of the ligament marginal, elongate, subexte- rior, dilated in the middle. The meleagrina is distinguished from avicula by the form of the shell, which is nearly equivalve, by never having the tail nor cardinal teeth, and by the widening of the ligamental facet at the middle part. The aper- ture for the byssus also occasions a callous, re-entering angle on each valve. It often contains true pearls. M. margaritifera, albina. GENERA OF SHELLS. 47 SECT. II. — LIGAMENT NOT MARGINAL, CONTRACTED INTO A SMALL SPACE UNDER THE BEAKS ; ALWAYS VISIBLE, AND NOT FORMING A TENDINOUS CORD UNDER THE SHELL. These shells are generally auriculated at the base or extremity of the cardinal margin. They are all ine- quivalve, for though in many the valves are of the same size, one of them is always more convex than the other. 9 PECTENIDES. Ligament interior or semi-interior ; shell generally regular, compact , not foliated. PEDUM. Shell inequivalve, somewhat eared, inferior valve gaping ; beaks unequal, distant. Hinge toothless ; ligament partly exterior, in- serted in an elongated, canal-shaped fossa, under the beaks ; inferior valve emarginate near its posterior base. The pedurn is a free, regular, inequivalve shell ; and the singular notch of the lower valve shows that the animal has the power of attaching it by a byssus. P. spondyloideum. LIMA. Shell longitudinal, subequivalve, eared, slightly gaping on one side between the valves ; beaks distant, internal face in- clined outwards. Hinge toothless ; cardinal fossa partly exterior, receiving the ligament. The lirna has no notch on the lower valve ; the little ears, though small, are distinct. It differs from the 48 GENERA OF SHELLS. ostrea by being regular, free, and almost equivalve, and from pecten by its remote beaks and cardinal pit. They are sea shells, and generally white. L. inflata, squamosa, glacialis, annulata, fragilis, lin- guatula. PLAGIOSTOMA. Shell subequivalve, free, sub- auriculated, cardinal base transverse, straight; beaks rather distant, their inner sides expand- ing into transverse, flattened, external facets, one straight, the other obliquely inclined. Hinge without teeth ; a conical, cardinal pit, under the beaks, partly internal, opening out- wards, and receiving the ligament. It is only known in the fossil state. PECTEN. Shell free, regular, inequivalve, eared ; inferior edge transverse, straight ; beaks contiguous. Hinge toothless ; cardinal fossa wholly interior, triangular, receiving the liga- ment. The pectines are almost always radiated with fine or coarse ribs. The base of the shell is terminated by a straight, transverse line, beyond which the beaks never project. The valves are generally thin, of equal size, but the upper one almost constantly flattened. They are always eared, and the largest ear is on the posterior side, and beneath it is a sinus. (a.) Ears equal, or nearly so. P. maximus, medius, Jacobaeus, bifrons, ziczac, Laurentii, pleuronectes? obliterates, Japonicus, magellanicus, purpura- tus, lineolaris, radula, rastellum, turgidus, flagellatus, asper- GENERA OF SHELLS. 49 sus, flavidulus, plica, glaber. sulcatus, virgo, unicolor, gri- seus, distans, Isabella, — concentricus, Pealii, ornattis, dis- locatus. (&.) Ears unequal. P. nodosus, pallium, pes felis, tigris, imbricatus, histri- onicus, sauciatus, opercularis, lineatus, flabellatus, irradians, flexuosus, inflexus, dispar, quadriradiatus, Islandicus, asper- rimus, senatorius, aurantius, florens, varius, sanguineus, sin- uosus, ornatus, pellucidus, Tranquebaricus, gibbus, minia- ceus, pusio, hybridus, sulphureus, lividus, hexactes. PLICATULA. Shell inequivalve, without ears, attenuated at base, superior margin plaited, rounded ; beaks unequal, and without exter- nal facet. Hinge with two strong teeth on each valve ; a pit between the two teeth, re- ceiving the ligament, which is entirely exte- rior. The plicatula differs from the pecten by having car- dinal teeth, and being without ears, and from spon- dylus, by having no external facet and no spines. P. ramosa, depressa, cristata, reniformis, australis. SPONDYLUS. Shell inequivalve, adherent, eared, spiny or rigid ; beaks unequal ; inferior valve presenting a cardinal area external, flat- tened, divided by a fissure, which increases with age. IJinge with two strong cardinal teeth in each valve, with an intermediate liga- mentary fossa connected by a sulcus to the external fissure ; ligament internal. 4 50 GENERA OF SHELLS. The spondyli are distinguished from thq ostreee by the cardinal teeth ; they are generally covered with spines, which are occasionally very large, disposed in rows or radiating strise or ribs. The lower valve is always largest and most convex, and is terminated at the beak by a kind of flattened, inclined, triangular facet, which appears as if cut with a knife, and increas- ing by age. S. geedaropus, Americanus, arachnoides, candidus, multi- lamellatus, costatus, variegatus, longi-spina, regius, avicu- laris, coccineus, crassi-squama, spathuliferus, ducalis, longi- tudinalis, microlepos, croceus, aurantius, radians, zonalis, violascens. PODOPSIS. Shell inequivalve, subregular, adhering by the inferior beak, not auriculated, the lower valve largest, most convex, and the beak most produced ; hinge toothless ; liga- ment interior. Fossil. OSTRACEA. Ligament internal or s emi- internal ; shell irregular, foliated } sometimes very thin. The ostracea are seldom auriculated at base, and still more rarely radiated externally ; in many species the shell is fixed to marine bodies by the lower valve, which is always the largest. («.) Ligament semi-internal ; shell foliated, and often very thick. GRYPHJEA. Shell free, inequivalve ; inferior valve large, concave, terminated by a project- ing beak, curved spirally inwards; superior GENERA OF SHELLS. 51 valve small, flat, like an operculum. Hinge toothless ; an oblong cardinal pit. The curved beak of these shells usually projects considerably, either above the upper valve or laterally. They are almost always free shells, and are all fossil, but one species. G. angulata vel tricarinata. OSTREA. Shell adherent, inequivalve ; irreg- ular ; beaks distant, becoming very unequal by age ; the superior valve becoming displaced during life. Hinge toothless ; ligament semi- interior, inserted into the cardinal fossa ; fossa of the inferior valve increasing with age to a great length. The shell of the ostrea is rude, rugged, often scaly, sometimes singularly plaited at the margins, and fre- quently very thick. It does not curve upwards like that of the gryphsea. The texture of the valves is loose, foliated ; the lower one, which is the largest, and by which it adheres to marine bodies, is more convex than the upper. (1.) Margins simple or waved, not plaited. O. edulis, hippopus, borealis, Adriatica, cochlearis, cristata, gallina,mumisma, lingua, tulipa, Brasiliana, scabra, rostralis, parasitica, denticulata, spathulata, ruscuriana, Virginica, Can- adensis, excavata, mytiloides, sinuata, trapezina, tuberculata, rufa, margaritacea, gibbosa, australis, elliptica, haliotidea, deformis, fucorum — semicylindrica. (2.) Margins plaited. 0. cornucopia, cucullata, doridella, rubella, limacella, erucella, folium, labrella, plicatula, glaucina, fusca, turbi- nata, crista-galli, imbricata, hyotis, radiata. 52 GENERA OF SHELLS. VULSELLA. Shell longitudinal, subequivalve, irregular, free ; beaks equal. Hinge with a prominent callosity on each valve, depressed above, and exhibiting a conical and obliquely arcuated pit for the ligament. The vulsella is allied to the ostreae, but always has the valves nearly equal ; the beaks equal, though some- what separate ; an equal, projecting callus in the inte- rior of each valve under the beaks ; and it is never fixed by its lower valve. They are often found in sponges ; some species gape a little at the posterior side. V. lingulata, hians, rugosa, spongiarum, mytilina, ovata, deperdita. (6.) Ligament internal / shell thin, papyraceous* PLACUNA. Shell free, subequivalve, irregu- lar. Hinge internal, presenting on one valve two sharp, longitudinal ribs, in form • of V ; on the other, two corresponding impressions. The valves of the placunae are thin, transparent, and of the same size. They are large, orbicular or subtri- angular, and sometimes triangular. Their texture is foliated. P. sella, papyracea, placenta, pectinoides — pertusa, quad- rifasciata. ANOMIA. Shell inequi valve, irregular, oper- culated ; adhering by the operculum ; lower valve pierced, commonly flat, with a hole or notch at the beak ; the other larger, concave, entire ; operculum small, elliptic, osseous, fixed GENERA OF SHELLS. 53 to foreign bodies, to which is attached the inte- rior muscle of the animal. The operculum of the anomia has been absurdly mistaken for a third valve. The perforated flat valve is usually considered the lower one, because it is that which rests on the bodies to which it is attached. A. ephippium, patellaris, cepa, electrica, pyriformis, for- nicata, membranacea, squamula, lens. SECT. III. — LIGAMENT EITHER WANTING OR UN- KNOWN, OR REPRESENTED BY A TENDINOUS CORD, WHICH SUPPORTS THE SHELL. RUDISTA. Ligament^ hinge and animal unknown, shell very unequi- valve ; no distinct beaks. SPH^RULITES, Shell inequivalve, orbicular, globose, somewhat depressed above, echinated externally with large, subangular, horizontal scales ; upper valve smallest, rather flat, oper- cular ; internal surface with two unequal, sub- conical, curved and prominent tuberosities ; lower valve largest, rather ventricose, external margin with radiated scales ; cavity obliquely conical, forming at one side by the folding of the margin, a crest or projecting keel ; internal side of the cavity transversely striate. Hinge unknown. Fossil. RADIOLTTES. Shell inequivalve, externally striated ; striae longitudinal, radiating ; lower valve turbinated, and largest ; the upper con- 54 GENERA OF SHELLS. vex, or depressed conic, opercular. Hinge unknown. Fossil. CALCEOLA. Shell inequivalve, triangular, tur- binated, flattened beneath ; the larger valve hol- lowed or hood-shaped, obliquely truncated at the aperture ; cardinal margin straight, trans- verse, a small notch or indentation in the mid- dle ; superior margin arched ; the small valve flat, semi-orbicular, opercular, having a tuber- cle on each side of the cardinal margin, and in the middle a pit with a small lamina. Fossil. B mo s TRITE s. Shell inequivalve, two horned, disc of the valves obliquely elevated conically, unequal, obliquely diverging, nearly straight, horn-shaped, the one enveloping the other at base. Fossil. DISCINA. Shell inequivalve, rounded, oval, somewhat depressed ; valves nearly equal in size, each having a very distinct, central, orbi- cular disc ; disc of the superior valve not per- forated, rising into a mamillary protuberance ; that of the other valve very white, with a trans- verse slit. The identity of discina and orbicula has been so satisfactorily proved, that the former is now given up. D. ostreoides. CRANIA. Shell inequivalve, suborbicular ; inferior valve nearly flat, perforated on its in- ternal face by three unequal, oblique holes ; GENERA OF SHELLS. 55 superior valve convex, sub-gibbous, with two prominent callosities within. The three holes in the crania do not seem to perfo- rate it completely, unless by accident, when removed from the body to which it was fixed by the outer surface ; hence they cannot be the issues of muscles. These holes give the lower valve the appearance of a death's head. C. personata. BRACHIOPODA. The shell of the brachiopoda is more or less inequi- valve, and opens by a hinge ; the true ligament of the valve is not known. The shell always adheres to marine bodies. ORBICULA. Shell suborbicular, inequivalve ; no conspicuous hinge ; inferior valve very thin, flat, adhering to marine bodies ; superior sub- conic with an acute vertex more or less promi- nent. The lower valve is sometimes so thin as to be scarcely perceptible, whence Muller supposed it to be a univalve shell, and referred it. to the patellae. O. norvegica. TEREBRATULA. Shell inequivalve, regular, subtriangular, attached to marine bodies by a short, tendinous pedicle ; beak of the larger valve produced, often curved, perforated at summit by a round hole or a notch ; hinge with two teeth ; two nearly osseous, slender, elevated, forked, variously ramified branches 56 GENERA OP SHELLS. spring from the disc of the small valve, and serve as a support to the animal. T. vitrea, dilatata, pisum, globosa, rotundata, flavescens, dentata, dorsata, sanguinea, caputserpentis, truncata, psit- tacea. Fossils numerous. LINGULA. Shell subequivalve, flattened, oval oblong, truncated at summit, somewhat pointed at base, elevated on a fleshy, tendinous pedicle, fixed to marine bodies. Hinge toothless. L. anatina. MOLLUSCA. Body sometimes naked, either destitute of any solid inter- nal parts, or inclosing a shell or other hard substance, and sometimes provided externally with a shell, cover-r- ing or sheathing, but never composed of two oppo- site valves, united by a hinge. ORDER L— PTEROPODA. Some only, are furnished with a thin, cartilaginous or horny shell. HYAL^EANA. HYAL^A. Shell horny, transparent, ovate globose, tridentate posteriorly, open at sum- mit and two posterior sides. The shell of the hyalaea appears to consist of two valves cemented together. The valves are unequal ; the largest above, rather flattened beneath, the other below, tumid, subgk)bular, and shortened anteriorly. On each side of the shell is a very open fissure to admit water to the branchice. H. tridentata, cuspidata. GENERA OF SHELLS. 57 CLIO. Has no shell. CLEODORA. Shell gelatino-cartilaginous, transparent, like an inverted pyramid, or lan- ceolate, truncated and open superiorly. C. pyramidata, caudata. LIMACINA. Shell thin, fragile, papyraceous, spiral ; whorls in discoidal order, like planorbis. L. helicialis. CYMBULIA. Shell gelatino-cartilaginous, very transparent, crystalline, oblong, shoe-shaped, truncated at summit ; aperture lateral and in- terior. C. Peronii. PNEUMODERMON. No shell. ORDER II. — GASTEROPODA. Some are naked, others have a dorsal shell, not envelop* ing ; others again have a shell more or less hidden in a mantle. TRTTONIANA. Without shells, either external or internal. PHYLLIDIANA. Some are without shells either external or internal ; others are wholly or partly covered by a shell, sometimes com- posed of one single piece, sometimes of a range of mova- ble and distinct pieces. PHYLLIDIA. No shell. CHITONELLUS. Shell multivalve ; valves al^ ternate, mostly longitudinal, united to each 58 GENERA OF SHELLS. other by their extremities in form of a cater- pillar. The valves of the shell, whilst the animal is alive, are separate ; but when dead and contracted, several of them appear to be united. C. laevis, striatus. CHITON. Shell multivalve, arranged in a single longitudinal series ; valves movable, im- bricate, transverse, lateral extremities con- nected by a folding back of the mantle. The shell is generally composed of eight valves ; sometimes of seven, or only six ; the middle valves are longer than those at the extremities. C. gigas? squamosus, Peruvianus, spinosus, fascicularis, marginatus, Magellanicus. PATELLA. Shell univalve, not spiral, shield- like, or like a depressed cone; concave and sim- ple beneath, margin without fissure, summit entire, inclined anteriorly. The patellae are widest at the posterior side, and the outline of the shell is generally oval. Most of them have ribs, radiating from the summit to the margin. P. apicina, granatina, oculus, barbara, plicata, laciniosa, saccharina, angulosa, barbata, longicosta, spinifera, aspera, luteola, pyramidata, umbella, plumbea, ccerulea, radians, scutellaris, Safiana, testudinaria, cochlear, compressa, gran- ularis. deaurata, Magellanica, stellifera, vulgata, rnamillaris, lineata, leucopleura, notata, Tarentina, punctata, punctu* rata. Javanica, tuberculifera, miniata, viridula, pectinata, Galatbea, pellucida, tricostata, australis, cymbularia, — amoena, alternata. GENERA OF SHELLS. 59 SEMI-PHYLLIDIANA. PLEUROBRANCHUS., Shell internal, dorsal, thin, flattened, often oblique, oval. P. plumula, Peronii. UMBRELLA. Shell external, orbicular, some- what irregular, nearly flat, slightly convex above, white, with a small apicial point in the centre, edges sharp ; internal face a little con- cave, with a callous, colored disc, pitted in the centre, and surrounded by a smooth limbus. V. Indica, Mediterranea. CALYPTRICIANA. Shell always external, covering the animal. PARMOPHORUS. Shell oblong, subparallelo- piped, somewhat convex above, blunt at ex- tremities, notched anteriorly by a slight sinus, a small apicial point above, towards the poste- rior part, inclined backwards. P. australis, breviculus, granulatus. EMARGINULA. Shell conic, shield-like, vertex inclined ; posterior margin split or emarginate* The shells of this genus are generally small ; some of them in the form of a cone, inclined towards the anterior margin, which is always the narrowest, and opposite to that which has the fissure. In others, the cone is very much flattened. E. fissura, rubra. FISSURELLA. Shell shield-like, or depressed 60 GENERA OP SHELLS. conic, concave beneath, vertex perforated ; spire none ; foramen ovate or oblong. F. picta, nimbosa, crassa, Grseca, nodosa, Cayenensis, lila- cina, rosea, Barbadensis, radiata, viridula, hiantula, pustula, fascicularis, Javanicensis, depressa, Peruviana, gibberula, rainuta, alternata. PILEOPSIS. Shell obliquely conic, curved forwards, apex hooked, subspiral ; aperture round-elliptic; anterior margin shortest, acute, subsinuate ; posterior broader and rounded, an elongated, arched, transverse muscular impres- sion under the posterior margin. P. Ungarica, mitrula, intorta, subrufa, spirirostris, retor- tella, pennata, squamae form is. CALYPTR^EA. Shell conoid, orbicular at base ; vertex erect, imperforate, pointed ; base round, cavity with a convolute lip, or a spiral dia- phragm. C. extinctorium, loevigata, equestris, lectum-sinense, — striata. CREPIDULA. Shell ovate or oblong, gener- ally convex on the back, concave beneath ; spire strongly inclined to the margin ; aper- ture partly closed by a horizontal lamina. C. fornicata, poreellana, aculeata, unguiformis, dilatata, Peruviana, — depressa, glauca, plana, intorta, convexa. ANCYLUS. Shell thin, obliquely conic ; apex acute, curved backwards ; aperture oval ; mar- gins very simple. A. lacustris, fiuviatilis, spina rosae, — rivularis. GENERA OF SHELLS. @[ ACERA. No shell. BULL^EANA. BULLJEA. Shell very thin, partially convo- luted, and spiral at one side, without columella or spire ; aperture very large, patulous above. B. aperta. BULLA. Shell ovate globose, convolute, no columella nor projecting spire; aperture the whole length ; right margin sharp. B. lignaria, ampulla, striata, naucum, physis, fasciata, aplustre, hydatis, cornea, fragilis, solida, — solitaria. LAPLYSIANA. LAPLYSIA. Shield dorsal, semicircular, sub- cartilaginous. L. depilans, fasciata, punctata, radiata. DOLABELLA. Shell oblong, subarcuate, hatchet-shaped ; contracted, thick, callous and nearly spiral at one side ; the other broader, flatter and thinner. D. Rumphii, fragilis. LIMACIANA. ONCHIDIUM. No shell. PARMACELLA. No described shell. LIMAX. A coriaceous shield. TESTACELLA. Shell minute, external, sub- auriform, apex obsoletely spiral ; aperture very large, oval, obliquely dilated; left lip involute. T. haliotidea. 62 GENERA OF SHELLS. VITRINA. Shell small, very thin, depressed, terminated superiorly by a short spire ; last whorl very large ; aperture large, rounded- oval ; left margin arquated, slightly inflexed. V. pellucida. ORDER III.— TRACHELIPODA. Shells spirivalve, unsheathing. SECTION I. — TRACH. PHYTIPHAGA. Aperture of shell entire ; base without any ascending notch or canal. COLIMACEA. Shell spirivalve, with no other projecting parts on the exte- rior than the strice, of growth ; right margin of the aper- ture, often recurved or reflexed outwards. HELIX. Shell orbicular, convex or conoid, sometimes globular, spire not much elevated ; aperture entire, broader than long, very oblique, contiguous to the axis ; margins disjoined by the prominence of the penultimate whorl. The helix is distinguished from the pupa, by the general form of the shell, which is never cylindrical, and by the borders of the aperture being disunited ; from the bulimus, by the aperture being rather trans- verse than longitudinal, and its plane very oblique and almost perpendicular to the axis of the spine; and from planorbis by the left margin of the aperture being contiguous to the axis of the shell. The margin of the adult helix is always reflected outwards, which it never is in aquatic shells. The helix is readily GENERA OF SHELLS. 63 known by the projection of the penultimate whorl into the aperture. H. vesicalis, gigantea, polyzonalis, monozonalis, pulla, lineolata, mutata, pomatia, aspersa, vermiculata, Alonensis, versicolor, naticoides, picta, galactites, hremastoma, mela- notragus, extensa. lucana, globulus, melanostoma, cselatura, microstoma, maculosa, Richardi, Bonplandii, planulata, labrella, ungulina, pellis-serpentis, Senegalensis, unidentata, cepa, heteroclites, discolor, lactea, zonaria, guttata, Mada- gascarensis, Javanica, Peruviana, simplex, cidaris, citrina, algira, verticillus, olivetorum, plariospira, Barbadensis, sinu- ata, hippocastanum, bidentalis, argilacea, -vittata, alauda, arbustorum, candidissima, nernoralis, hortensis, sylvatica, Pisana, splendida, serpentina, Niciensis, variabilis, fruticum, neglecta, cespiturn, ericetorum, intersecta, carthusianella, carthusiana, diaphana, concolor, velutina, obvoluta, Cook- iana, pileus, papilla, punctifera, plicatula, planorbella, sea- bra, cariosa, crenulata, planorbula, macularia, maritima, stri- gata, muralis, rugosa, cornea, linguifera, incarnata, cinctella, cellaria, nitida, plebeium, personata, hispida, rotundata, api- cina, striata, conspurcata, conica, conoidea, pulehella, — albo- labris, hirsuta, perspectiva, lineata, thyroidus, minuta, laby- rinthica, multilineata, appressa, palliata, inflecta, clausa, obstricta, elevata, interna, chersina, gularis, ligera, solitaria, jejuna, concava, dealbata, profunda, alternata, irrorata, inor- nata, indentata, fallax, egena, tridentata, monodon. CAROCOLLA. Shell orbicular, more or less conoid or convex above, outline sharp and an- gular, or keeled ; aperture broader than long, contiguous to the axis ; lip subangular, often dentated or plaited beneath. The sharp edge of the last whorl, their being always orbicular, and sometimes considerably depressed, are the characteristics of this genus. 64 GENERA OF SHELLS. C^ acutissima, albilabris, angistoma, labyrinthus.lucerna, inflata, Gualteriana, bicolor, mauritiana, Madngascarensis, marginata, lychnuchus,planata, planaria, hispidula, lapicida, albella, elegans. ANASTOMA. Shell orbicular, spire convex, obtuse ; aperture rounded, dentated on both sides, within ringent, looking towards the spire ; lip reflected. The singular position of the aperture, directed up- wards towards the spine of the shell, is the character- istic of this genus, and peculiar to it. A. depressa, globulosa.* HELICINA. Shell subglobose, imperforate ; aperture entire, semi-oval ; columella callous, transverse, flattened, margin acute, forming an angle at the inferior base of the lip ; operculum horny. The helicinse resemble small neritse, but the latter are sea shells. They are distinguished from the helices by their transverse columella, which is callous, de- pressed, and thin at the lower part. They are land shells, and inhabit warm climates. H. neritella, slriata, faseiata, viridis, — major, orbiculata^ occulta. *POLYGYRA.— . Say. Shell discoidal; more or less carinated on the upper edge of the whorls j umbilicated j aperture longer than broad j lips thickened, toothed, or folded and continued, folds concave beneath j pillar lip raised above the preceding whorl, and concave beneath. P. auriculata, avara, septemvolva, plicata. GENERA OF SHELLS. 65 PUPA. Shell cylindrical, generally thick ; aperture irregular, semi-oval, rounded and subangular inferiorly ; margins nearly equal, reflected outwards,- disjoined above ; a colu- mellar lamina, firmly fixed, being interposed. P. mumia, uva, sulcata, Candida, labrosa, fusus, tridentata, fasciolata, zebra, unicarinata, rnaculosa, clavulata, ovularis, germanica, cinerea, tridens, quadridens, polyodon, variabilis, frumentum, secale, avena, granum, fragilis, dolium, umbili- cata, muscorum, — armifera, corticaria, rupicola, contracta, exigua, fallax, ovata, pentodon. CLAUSILIA. Shell generally fusiform, slen- der, somewhat obtuse at summit; aperture irregular, rounded oval ; margins united, free, reflected outwards. The essential character of the clausilia is, that the two borders of the aperture are completely united, free in their contour, and reflected outwards. C. torticollis, trimcatula, retusa, costulata, corrugata, in- flata, teres, denticulata, collaris, papillaris, plicatula, rugosa. BTJLIMUS. Shell ovate, oblong or turreted ; aperture entire, longitudinal; margins very unequal, disunited above ; columella straight, smooth, entire at the base, not channelled. The last whorl of the spine of the bulimus is larger than the penultimate ; the shell is never orbicular, like the helix ; it differs from the pupa by the great ine- quality of the two margins of the aperture, the right of which is sometimes considerably thickened. 5 66 GENERA OF SHELLS. B. ovatus, hsemastomus, gallina, sultana, zigzag, undatusf Richii, in versus, citrinus, sultanus, Pythogaster, ovoideus, interruptus, Peruvianus, Favannii, Kambeul, calcareus, decollatus, Lyonetianus, inflatus, radiatus, fragilis, Guadalup- ensis, Mexicanus, multifasciatus, Bengalensis, Caribaeo- rum, octonus, terebraster, articulatus, acutus, ventricosus, montanus, hordaceus, lubricus, — multilatus, multilineatus. ACHATINA. Shell ovate or oblong ; aper- ture entire, longer than broad ; lip sharp, never reflected. Columella smooth, truncated at base. This genus is well distinguished from the former by the right margin being never reflected, and by wanting that on the left ; the columella being always naked, very smooth, and truncated at the base. (a.) Last ichorl ventricose, not depressed. A. perdrix, zebra, immaculata, purpurea, acuta, bicarinata, mauritiana, castanea, ustulata, vexillum, virginea, Priam us. (b.) Last whorl depressed or attenuated towards the base. A. glans, Peruviana, albo-lineata, fusctf-lineata, fulminea, folliculus, acicula — solida. SUCCINEA. Shell ovate or ovate conic ; aper- ture ample, entire, longer than broad; lip acute, not reflexed, uniting inferiorly with the smooth, thin, sharp columella. No operculum. The succinese live habitually on land, near water, which they occasionally frequent. They are distin- guished from the bulimus by the right margin being never reflected, and from the lymnaja by their colu- mella being free from folds. S. cucullata, amphibia, oblonga — ovalis, campestris. GENERA OF SHELLS. 67 AURICULA. Shell sub-oval or ovate oblong ; aperture longer than broad, very entire at base, narrowing upwards where its margins are disunited, columella with one or more plaits. Lip with the margin sometimes re- flected, sometimes simple and sharp. Land shells, and distinguished from bulimus by the folds on the columella. (a.) Shells with the margin reflected outwards. A. auris-midae, a. Judae, a. Sileni, a. leporis, a. Gelis, scara- bseus, bovina, caprella, myosotis, minima. (&.) Shells with the margin simple and acute. A. Dombeiana, coniformis, nitens, monile. CYCLOSTOMA. Shape of shell variable ; whorls cylindrical, aperture circular, regular ; margins continuous, dilated or reflected by age. An operculum. Land shells, never pearly, generally thin, and with- out scales or tubercles on the outside ; distinguished from the paludina by the outward reflection of the margin of the adult shell ; whilst in paludina it is always sharp, and not reflected ; from the pupa by the regularity of the aperture, which is never angular. C, planorbula, volvulus, carinata, sulcata, unicarinata, tricarinata, obsoleta, rugosa, labeo, interrupta, ambigua, sem- ilabris, flavula, fasciata, mumia, quaternata, ferruginea, de- cussata, lineolata, mammillaris, ligata, lincinella, orbella, fimbriata, multilabris, elegans, patulum, truncatulum — lapidaria, marginata, dentata. 68 GENERA OF SHELLS. LYMNEANA. Shell spirivalve, the external surface mostly smooth ; the right margin of the aperture always sharp and not reflected. PLANORBIS. Shell discoidal, spine depress- ed, scarcely prominent ; whorls apparent above and below ; aperture oblong, lunated, very dis- tant from the axis ; margin never reflexed. Operculum none. Fresh water shells, generally thin, brittle, diapha- nous ; the whorls of some are subcylindrical, of others carinate or angular. Aperture sublongitudinal,with an internal projection formed by the penultimate whorl. P. cornu-arietis, corneus, carinatus, lutescens, orientalis, spirorbis, vortex, deformis, contortus, hispidus, nitidus, im- bricatus — armigerus, trivolvis, bicarinatus, parvus, paralle- lus, exacuus, campanulatus, glabratus. PHYSA. Shell convolute, or oblong ; spire prominent. Aperture longitudinal, narrowing superiorly. Columella twisted. Lip very thin, sharp, produced somewhat beyond the plane of the aperture. No operculum. Fresh water shells, thin, brittle, and generally re- versed ; distinguished from bulla by their projecting spire, and from lymnaea by the aperture not being dila- ted, the right margin projecting a little above its plane. P. castanea, fontinalis,hypnorum, subopaca, rivalis — gy- rjna, elongata, heterostropha, ancillaria. LYMNJEA. Shell oblong, sometimes tur- reted ; spire prominent. Aperture entire, Ion • gitudinal. Lip sharp, its inferior part rising GENERA OF SHELLS. 69 upon the columella, forming a very oblique fold as it enters the aperture. No operculum. The very oblique fold on the columella, distinguishes it from bulimus, and the regular, uninterrupted plane of the aperture from the physa. L. columnaris, stagnalis, palustris, Virginiana, luteola, acuminata, auricularia, ovata, peregra, intermedia, leucosto- ma, minuta, — - columella, elongata, catascopium, reflexa, ap- pressa, elodes, desidiosa, macrostoma, emarginata, humilis, modicella, obrussa, pinguis, galbana. MELANIANA. Margins of the aperture of the shell disunited, the right al- ways sharp. MELANIA. Shell turreted. Aperture entire, ovate or oblong, effuse at base. Columella smooth, incurved. A horny operculum. M. asperata, truncata, coarctata, punctata, corrugata, subu- lata, IsBvigata, clavus, decpllata, amarula, thiarella, spinulosa, granifera, carinifera, truncatula, fasciolata, — nupera, depygis, Virginica, semicarinata, laqueata, canaliculata, elevata, conica, catenaria, multilineata, simplex, proxima. MELANOPSIS. Shell turreted. Aperture en- tire, ovate oblong. Columella callous superi- orly, truncated at base, separated from the lip by a sinus. Operculum. The callus on the upper part of the columella dis- tinguishes melanopsis from melania, as well as its being truncated at base, like the achatina, which Is never the case in melania. M. costata, Ia3vigata. 70 GENERA OF SHELLS. PIRENA. Shell turreted. Aperture longi- tudinal ; lip sharp, with a sinus at the base and another at the summit. Base of columella curved towards the lip. Operculum horny. Principally distinguished from melanopsis by having no callus on the columella, and from that genus and melania by a sinus both at the base and summit of the right lip. P. terebralis, spinosa, aurita, granulosa — scalariformis. PERISTOMIANA. Shell operculatedj conoidal or subdiscoidal : margin of the aperture united. VALVATA. Shell discoidal or conoid ; whorls cylindrical, not modifying the spiral cavity. Aperture rounded ; margins united, sharp. An orbicular operculum. V. piscinalis — tricarinata. PALUDINA. Shell conoid ; whorls rounded or convex, modifying the spiral cavity. Aper- ture round-oval, longitudinal, angular at sum- mit. Lips united, sharp, never curved out- wards. Operculum, round, horny. The paludinee generally live in fresh water, though some inhabit brackish, and even salt water. They are distinguished from the valvataB by the somewhat elon- gated and angular form of the aperture. P. vivipara, achatina, Bengalensis, unicolor, impura, mu- riatica, viridis, — decisa, vivipara, subpurpurea, intertexta, ponderosa, integra, porata, limosa, decipiens, lustrica, grana, GENERA OF SHELLS. 71 AMPULLARIA. Shell globular, inflated, um- bilicated at base, without callosity on the pillar lip. Aperture entire, oblong ; margins united. Lip sharp, not reflexed. Operculum. The last whorl is at least four times as large as the penultimate. The colurnellar lip projects, and is re- flected over the umbilicus, forming a half funnel, but no callus. The shells are generally large. A. Guyanensis, rugosa, fasciata,canaliculata, effusa, Guin- iaca, virens, carinata, avellana, intorta, fragilis. NERITACEA. Shell fluviatile or marine, semiglolular or flattened oval, without columellctj the left margin of the opening resem- bling a half partition. (1.) Fresh water shells. NAVICELLA. Shell elliptic or oblong, con- vex above, concave beneath ; spire straight, bending over to the lip. Columella flattened, sharp, narrow, toothless, almost transverse. Operculum solid, flat, with a subulate lateral tooth. Distinguished from nerita and neritina by the sum- mit not being spirally convolute. The transverse left lip never covers half the cavity. N. elliptica, lineata, tessellata. NERITINA. Shell thin, semiglobose or oval, flattened beneath, not umbilicated. Aperture semicircular, pillar lip flattened and sharp : no teeth nor crenulations on the internal surface 72 GENERA OF SHELLS. of the outer lip. Operculum with a lateral tooth. N. perversa, pulligera, dubia, zebra, zigzag, gagates, lugu- bris, corona, brevispina, crepidularia, auriculata, Domingen- sis, fasciata, lineolata, semi-conica, strigilata, meleagris, virginea, fluviatilis, viridis, Boetica. (2.) Marine shells. NERITA. Shell solid, semiglobose, flattened beneath, without umbilicus. Aperture semi- orbicular, entire ; pillar lip flattened, septiform, sharp, often toothed ; teeth or crenulations on the internal face of the outer lip. Operculum with an apophysis. The spire is but little elevated above the last whorl. The operculum is crescent shaped, horny or calcareous, and exactly closes the aperture. The nerita differs from neritina by the internal face of the right margin being crenate, and from natica by having- no umbilicus. N. exuviartextilis, undata, peloronta, chlorostoma, atrata, polita, albicilla, chamoeleon, versicolor, Ascensionis, Malac- censis, lineata, scabricosta, plicata, tessellata, signata. NATICA. Shell subglobose, umbilicate. Aper- ture entire, semi-circular ; pillar lip oblique, not toothed, callous : callosity modifying the umbilicus and sometimes covering it. Outer lip sharp, always smooth within. An opercu- lum. Distinct from nerita by the umbilicus, and by the columellar margin not being crenate but smooth and callous, and by the smoothness of the interior of the right lip. GENERA OF SHELLS. 73 N. glaucina, albumen, mamillarisj mamilla, melanostoma, aurantia, conica, plumbea, ampullaria, canrena, cruentata, millepunctata, vitellus. helvacea, collaria,monilifera, labrel- la, rufa, unifasciata, lineata, fulminea, maculosa, vittata, castanea, Marochierisis, arachnoidea, zebra, zonaria, Chinen- sis, Javanica, cancellata, — triseriata, duplicata, rugosa, heros, pusilla. JANTHINEA. JANTHINA. Shell ventricose, conoid, thin, pellucid. Aperture triangular : columella straight, produced beyond the base of the lip : lip having a sinus in the middle. No opercu- lum. J. communis, exigua. MACROSTOMIANA. Shell ear shaped, aperture much dilated, the margins disu- nited, no columella, no operculum. SIGARETUS. Shell subauriform, nearly or- bicular, pillar lip short and spiral. Aperture entire, much dilated, longer than broad, mar- gins disconnected. S. haliotideus, concavus, laevigatus, cancellatus — per- spectivus, maculatus. STOMATELLA. Shell orbicular or oblong, auriform, imperforate. Aperture entire, am- ple, sublongitudinal ; lip effuse, dilated, gaping. Distinguished from stomatia by not having the trans- verse rib of that shell, nor the right lip so much ele- vated: and from haliotis, by wanting the foramina which mark that genus. 74 GENERA OF SHELLS. S. imbricata, rubra, sulcifera, auricula, planulata. STOMATIA. Shell earshaped, imperforate ; spire prominent. Aperture entire, oblong, ample ; lips equally raised. A transverse, tuberculous rib along the back. Distinguished from haliotis by the dorsal rib being imperforate. S. phymotis, obscurata. HALIOTIS. Shell earshaped, generally flat- tened ; spire very short, sometimes depressed, nearly lateral. Aperture very large, longer than broad, entire in its perfect state. Disc per- forated with holes disposed in a line parallel to to the pillar lip, and near it, the last beginning by a notch. H. Midse, iris, tubifera, excavata, australis, tuberculata, striata, asinina, glabra, lamellosa, unilateralis, rugosa, ca- naliculata, tricostalis, dubia. PLICACEA. Aperture of the shell not effuse ; columella plaited. Distinct from the auriculae by their general form and projecting spire; and from voluta, mitra, &c. by having no notch at the base of the aperture. TORNATELLA. Shell convolute, ovate cy- lindrical, generally striated transversely, and free from epidermis. Aperture oblong, entire ; lip sharp. One or more folds on the columella. T. flammea, solidula, fasciata, auricula, nitidula, pedipes.' PYRAMIDELLA. Shell turreted, destitute of GENERA OF SHELLS. 75 epidermis ; aperture entire, semioval ; lip sharp. Columella produced inferiorly, subperforate at base, with three transverse plaits. P. terebellum, — dolabrata, plicata, corrugata, maculosa. SCALARIANA. Shell imthout plaits on the columella ; margins of the aper- ture circularly united. The shells of the scalarianae have a tendency to form a loose spire, so that the whorls are often disunited and do not rest on one another. VERMETUS. Shell thin, tubular, loosely spiral ; spire adhering by its apex ; aperture circular ; margins united. Operculum. This shell greatly resembles a serpula : but its ani- mal is not one of the annulata, but a true molluscum. V. lumbricalis. SCALARIA. Shell subturreted, with longi- tudinal, elevated, interrupted, nearly sharp ribs ; aperture nearly circular ; the two margins unit- ing and terminated by a thin, recurved rim. S. pretiosa, lamellosa, coronata, varicosa, communis, aus- tralis, raricosta, — multistriata, liheata, clathratulus. DELPHINULA. Shell subdiscoidal or coni- cal ; umbilicated, solid ; whorls rough or angu- lar. Aperture entire, round, sometimes trian- gular; margins united, generally fringed or rimmed. Distinguished from turbo by the united margins. 76 GENERA OF SHELLS. D. laciniata, distorta, turbinopsis, — laxa. TURBINACEA. Shell turrcted or conoidal ; aperture round and oblong, not effuse, margins disunited. All sea shells, and appear to be operculated. When placed on the base, the axis is always more or less in- clined, never vertical. SOLARIUM, Shell orbicular, in form of a depressed cone, umbilicated ; umbilicus open, crenulated, or dentated on the internal margin of the spires ; aperture subquadrangular. Co- lumella wanting. The crenate umbilicus of the solarium sufficiently distinguishes it from the trochus and planorbis. S. perspectivum, granulatum, laevigatum, stramineum, hybrid um, variegatum, luteum. ROTELLA. Shell orbicular, shining, without epidermis ; spire very short, subconic ; inferior face convex, callous ; aperture semicircular. Distinguished from trochus by the lower surface being remarkably callous, and from helicina by the callus not being confined to the cohimellar lip, but ex- tending over a large portion of the lower side of the shell. • R. lineolata, rosea, suturalis, monilifera, Javanica. TROCHUS. Shell conical ; spire elevated, sometimes abbreviated ; outline more or less angular, often thin and sharp ; aperture trans- versely depressed ; margins disunited above. GENERA OF SHELLS. 7? Columella arcuated, more or less swelling at base. Operculum. Many trochi have a brilliant, pearly surface, and sev- eral have longitudinal ribs, which, we believe, are never found in the turbo. T. imperialis, longispina, Solaris, Indicus, radians, pileus, calyptraBformis, fimbriatus, brevispina, rotularius, Stella, stel- laris, rhodostomus, spinulosus, costulatus, inermis, agglu- tinans, coelatus, tuber, magus, merula, argyrostomus, Cookii, Niloticus, pyramidalis, noduliferus, coerulescens, obeliscus, virgatus, maculatus, granosus, squarrosus, incrassatus, flam- mulatus, elatus, marmoratus, mauritianus, imbricatus, trise- rialis, crenulatus, asperulus, acutus, lineatus, ziziphinus, conuloides, conulus, jujubinus, Javanicus, annulatus, dola- rius, granulatus, granatum, moniliferus, iris, ornatus, bicin- gulatus, calliferus, umbilicaris, undatus, Pharaonis, sagitti- ferus, carneolus, cinerarius, excavatus, nanus, pyramidatus, erythroleucos. MONODONTA. Shell ovate or conical ; aper- ture entire, rounded ; margins, disconnected above; columella arcuated, truncated at base. Operculum. Distinguished from trochus chiefly by the more cir- cular form of the mouth : from turbo by the columella being truncated at base and forming the characteristic tooth-like projection in the aperture. M.bicolor, pagodus, tectum-persicum,papillosa, coronaria, ^Egyptigca, carchedonius, modulus, tectum, labio, australis, canalifera, viridis, fragaroides, constricta, tricarinata, articu- lata, lugubris, punctulata, canaliculata, seminigra, rosea, lineata. TURBO. Shell conoid or subturreted ; out- 78 GENERA OF SHELLS. line never compressed ; aperture entire, round- ed, not modified by the penultimate whorl : margins separate above. Columella arcuated, flattened, not truncated at base. Operculum. The axis of the shell is generally more inclined than that of the trochus. T. marmoratus, imperialis, torquatus, Sarmaticus, cornu- tus, argyrostomus, chrysostonms, radiatus, margaritaceus, setosus, Spenglerianus, petholatus, undulatus, pica, versico- lor, smaragdus, cidaris, diaphanus, rugosus, coronatus, crenulatus, hippocastaneum, muricatus, littoreus, ustulatus, Nicobaricus, neritoides, retusus, rudis, obtusatus, pullus, coerulescens, cancellatus, costatus, — irroratus, canaliculatus, palliatus, vestita, obligatus. PLANAXIS. Shell ovate, conical, solid ; aperture ovate, sublongitudinal. Columella flat, truncated at base, separated from the outer lip by a narrow sinus. Interior surface of the right magin furrowed or lineated, and a callos- ity running under the summit. The planaxis is distinguished from phasianella by the truncation of the columella: it is transversely fur- rowed externally, and generally small in size. P. sulcata, undulata. PHASIANELLA. Shell oval or conic, solid; aperture ovate, longer than broad, entire; lips separate above, the right sharp, not reflected. Columella smooth, compressed, attenuated at base. Operculum calcareous or horny. GENERA OF SHELLS. 79 P. bulimoides, rubens, variegata, elegans, Peruviana, ne- bulosa, sulcata, Mauritiana, angulifera. TURRITELLA. Shell turreted, not pearly ; aperture rounded, entire ; lips disunited above, the right having a sinus. Operculum horny. Distinguished from turbo by the general form of the shell and by the sinus on the right lip, a constant character. Most of the species are transversely carin- ated or striated, but none of them have vertical ribs, varices or tubercles. T. duplicata, terebra, imbricata, replicata, fuscata, cornea, brevialis, bicingulata, trisulcata, exoleta, carinifera, australis, Virginiana, — concava, sequalis, alternata, reticulata, im- pressa, bisuturalis, SECT. II.— TRACHELIPODA ZOOPHAGA. Shell spirivalve, ensheathing : aperture either canaliculate, notched or inclined at the base. CANALIFERA. Shell with a caned more or less long at the base of the aperture, the right lip of which does not change its form by age. DlV. I. — 'NO CONSTANT VARIX ON THE OUTER LIP. CERITHIUM. Shell turreted ; aperture ob- long, oblique, terminated at its base by a short canal, truncated or recurved, never emarginate. A slight channel at the upper extremity of the lip. Operculum, small, orbicular, horny. The spire of the shell constitutes at least two thirds 80 GENERA OF SHELLS. of its whole length : the last whorl being but little larger than the preceding one, the shell has the form of an elongated pyramid: surface generally striated or tubercular and sometimes varicose. C. giganteum, palustre, sulcatum, telescopium, ebeninum, nodulosum, vulgatum, obeliscus. granulatum, aluco, echina- tum, erythra3onense, muricatum, radula, crassum, decolla- tum, obtusum, semigranosum, asperurn, lineatum, vertagus, fasciatum,subulatum, heteroclites,zonale, semiferrugineum, torulosuin, tuberculatum, morus, ocellatum, litteratum, atra- tum, eburneum, punctatum, lima, perversum, — muscarurn, septemstriatum, ferrugineum, dislocatum. PLEUROTOMA. Shell either turreted or fusi- form ; terminated inferiorly by a straight canal more or less elongated. Lip at its upper part having a fissure or emargination. P. imperialis, auriculifera, muricata, echinata, flavidula, interrupta, crenularis, cincta, unizonalis, lineata, spirata, fascialis, birnarginata, buccinoides, cingulifera, virgo, baby- lonia, undosa, marmorata, tigrina, crispa, albina, nodifera. TURBINELLA. Shell turbmated or subfusi- form, channelled at base. Columella with three to five compressed, transverse plaits. Distinguished from voluta by the canal at the base of the aperture : from murex by having no varices, and from fasciolaria by the direction of the folds on the columella. T. scolymus, rapa, napus, pyrum, pugillaris, rhinoceros, cornigera, ceramica, capitellum, mitis. globulus, leucozona- lis, rustica, cingulifera, polygona, carinifera, infundibulum, craticulata, lineata, nassatula, triserialis, variolaris, ocellata. GENERA OF SHELLS. Q\ CANCELLARIA. Shell oval or turreted ; aperture sub- channelled at base ; canal very short or wanting. Columella plaited, the folds few or numerous, for the most part transverse ; lip furrowed within. C. reticulata, asperella, scalarina, scalariformis, nodulosa, cancellata, senticosa, citharella, spirata, obliquata, rugosa, ziervogeliana. FASCIOLARTA. Shell subfusiform, channelled at base, without varices. Columella having two or three very oblique folds near the canal. Distinguished from fusus by the folds on the colu- mella, and from turbinella by their oblique direction. F. tulipa, clistans, trapezium, aurantiaca, filamentosa, coronata, ferruginea, Tarentina. Fusus. Shell fusiform or subfusiform ; channelled at base, ventricose at the middle or inferiorly, without varices. Spire elevated and elongated. Lip entire ; columella smooth. Operculum horny. F. colosseus, longissimus, colus, tuberculatus, Nicobaricus, distans, torulosus, incrassatus, multicarinatus, sulcatus, an- tiquus, despectus, carinatus, proboscidiferus, Islandicus, mo- rio, coronatus, cochlidium, corona, raphanus, filosus, ])o\y- gorioides, verruculatus, lignarius, Syracusanus, strigosus, varius, crebricostatus, afer, rubens, sinistralis, Nifat, articu- latus, buccinatus, aculeiformis, scalarinus, contrarius, — cor- neus, cinereus, bicolor, decemcostatus, fluviatilis. PYRULA. Shell sub-pyriformj channelled at base, ventrieose above, without varices ; spire 6 82 GENERA OF SHELLS. short sometimes flattened. Columella smooth. Lip entire. The pyrula differs widely from fusus, by its short spire, and by the remarkable inflation of the last whorl, being always at the upper part of the shell. P. canaliculata, carica, perversus, candelabrum, tuba, bu- cephala, vespertilio, melongena, reticulata, ficus, ficoides, spirata, spirillus, elongata, ternatana, bezoar, rapa, papyra- cea, galeodes, angulata, squamosa, nodosa, citrina;abbreviata, neritoidea, deformis, lineata, plicata. DlV. II. LlP CONSTANTLY WITH CALLUS, IN ALL SPECIES. STRUTHIOLARIA. Shell oval, spire elevated ; aperture oval, sinuated, terminated at base by a very short canal, straight, entire. Pillar lip callous, expanded, outer lip sinuate, thickened without. The struthiolaria is distinguished from buccinum by having no notch at the base of the canal, and by the varix on the right lip. — It has no other varix. S. nodulosa, crenulata. RANELLA. Shell ovate or oblong, sub-de^ pressed, channelled at base, with two rows of varices exteriorly ; aperture rounded or sub- ovate ; varices more or less oblique, at each half of a turn, forming a longitudinal series on each side. Distinguished from struthiolaria and murex by the position of the varices and somewhat flattened form of the shell. GENERA OF SHELLS. 83 R. gigantea, leucostoma, candisata, argus, crumena, spi- nosa, bufonia, granulata, granifera, semigranosa, bitubercu- laris, ranina, anceps, pygmrea, lasvigata, — caudata. MUREX. Shell ovate or oblong, channelled at base, with rough tubercular or spiny varices without. Aperture rounded ; varices three or more on each whorl, the inferior obliquely joined to the others by a longitudinal series. Operculum horny. The struthiolaria has only one varix, which is on the right lip : the ranella two, at opposite sides of the shell, and the murex three or more on each whorl, forming longitudinal rows on the shell, inclining to- wards one side near the summit of the spire. (I.) Shells icith slender, abrupt tails, always longer than the aperture. M. cornutus, brandaris, crassispina, tenuispina, rarispiria, ternispina, brevispina, haustellum, tenuirostrum; motacilla. (2.) Tails thick, not abrupt, more or less long. — (a.) Three varices. M. inflatus, elongatus, palmarosee, brevifrons, calcitrapa, adustus, rufus, axicornis, cervicornis, aculeatus, microphyl- lus, capucinus, asperrimus, phyllopterus, acanthopterus, tripterus, trigonularis, uncinarius, hemitripterus, gibbosus, triqueter, trigonulus. (b.) More than three varices. M. brassica, saxatilis, endivia, radix, melanomathos, hexa- gonus, scorpio, secundus, quadrifrons, turbinatus, trunculus, anguliferus, melonulus, Magellanicus, lamellosus, erinaceus, Tarentinus. scaber, costularis, polygonulus, vitulinus, an- gularis,crispatus,fenestratus, cingulatus, cinguliferus, subca- rinatus, torosus, lyratus, concatenatus, granarius, fimbriatus, pulchellus, aciculatus, tripteroides, tricarinatus. 84 GENERA OF SHELLS. TRITON. Shell oval or oblong, channelled at base ; varices alternate, rare or subsolitary, never forming a longitudinal series. Aperture oblong. Operculum. Sometimes the triton has only one varix, viz. on the right lip, which is never wanting. The varices are generally smooth, never spinous. T. variegatum,nodifernm, australe, lampas, scrobiculator, Spengleri, corrugatum, succinctum, pileare, lotorium, femo- rale, pyrum, cynocephalum, tripus, eanaliferurn, retusum, clavator, tuberosum, vespaceum, chlorostornum, anus, cla- thratum, subdistortum, cancellatum, maculosum, clandes- tinum, rubecola, cutaceum, dolarium, tranquebaricum, undosum. ALATA. Shell with a more or Jess elongated canal at the base of the aperture, the right lip of lohich changes its farm with age, and has a sinus at the lower part. ROSTELLARIA. Shell fusiform or subturret- ed, terminated inferiorly in a canal, with a pointed beak. Lip entire or dentated, more or less dilated by age, with a sinus contiguous to the canal. The right lip of these shells rests, at the upper part, against the elongated spire, and sometimes runs along it : the sinus at the lower part of the same lip is quite contiguous to the canal, which is not the case either with pterocera or strombus. R. curvirostris, recticornis, pes pelicani, macroptera, co- lumbata, fissurella. GENERA OF SHELLS. 85 PTEROCERA. Shell ovate oblong, ventricose, terminated inferiorly by an elongated canal. Lip dilating by age into a digitate wing, and having a sinus towards the base. Spire short. The canal at the base is not shortened and truncated as in the strombi, but elongated and caudiforrn, attenu- ated towards the extremity and frequently closed. The sinus is not contiguous to the body of the shell as in rostellaria. The strornbi differ only in wanting the digitations of the dilated wing and by their short canal. P. truncata, lambis; millepeda, pseudo scorpio, scorpio, aurantia, chiragra. STROMBUS. Shell ventricose, terminating in a short emarginate or truncate canal. Lip dilating by age into a simple wing, lobed or crenate superiorly, and having a sinus distinct from the canal or ernargination of the base, inferiorly. Distinguished from pterocera by the digitations of the right lip and by the canal being short, truncated or notched : from rostellaria by the sinus being separated from the canal by a portion of the lip. S. gigas, accipitrinus, latissimus, tricornis, gallus, bitu- berculatus, cristatus, dilatatus, bubonius, lentiginosus, auris Dianae, pugilis, pyrulatus, gibberulus, luhuanus, Mauritianus, canarium, Isabella, vittatus, epidromis, columba, succinctus, troglodytes, tridentatus, urceus, plicatus, floridus, papilio, lineatuSj marginatus? turritus, cancellatus, canalis. 86 GENERA OF SHELLS. PURPURIFERA. Shell with a short canal ascending posteriorly, or an oblique notch or demi-canal at the base of the aperture, directed to- wards the back. Div. I. — CANAL ASCENDING OR CURVED TOWARDS THE BACK. CAS SID ARIA. Shell obovate, or ovate ob- long. Aperture longitudinal, narrow, termin- ating at base, in a curved, subascending canal. Lap varicose or reflected ; pillar lip covering the columella, often rough, granular, tubercu- lous or wrinkled. Distinguished from cassis by being, in general, less inflated, but chiefly by its short canal, not being ab- ruptly turned towards the back of the shell and being but slightly curved or ascending. The spire is short, without continuous varices : the columella is generally loaded with small, oblong, wrinkled tubercles lying in a transverse direction. (a.) Spire having1 varices. C. echinophora, thyrrena, cingulata, striata, oniscus, cancellata, carinata, flammea, fasciata, glauca, crumena, plicaria, areola, zebra, decussata, abbreviata. (£>.) Spire without varices. C. rufa, pennata, testiculus, achatina, pyrum, zeylanica, sulcosa, granulosa, saburon, canaliculata, semigranosa, vibex, erinaceus, harpseformis. CASSIS. Shell inflated. Aperture longi- tudinal, narrow, terminated at base by a short canal, turning abrupt backwards. Columella GENERA OF SHELLS. 87 plaited or transversely wrinkled. Lip usually dentated. Distinguished from buccinum by the longitudinal direction and narrow form of its aperture, by the right lip being toothed, by the flattening of the pillar lip, which generally projects considerably to the left side, and by the abrupt reflection of the base of the canal towards the back of the shell. The spire is but little elevated and often interrupted by oblique, keel-shaped varices. C. tuberosa, Madagascarensis, cornuta. DlV. II. AN OBLIQUE NOTCH INCLINING BACK- WARDS. RICINULA. Shell ovate, generally tubercu- lous or spinous without. Aperture oblong, presenting inferiorly a semicanal, turning back- wards, terminated by an oblique notch ; une- qually toothed on the columella and internal surface of the lip, generally contracting the aperture. The ricinulaB are generally small shells : the spire often low and covered with tubercles or spinous points like the fruit of the ricinus. The aperture is generally tinged with purple or violet. R. horrida, miticula, clathrata, arachnoides, digitata, as- pera, morus, mutica, pisolina. PURPURA. Shell oval, sometimes smooth, sometimes tuberculous or angular. Aperture dilated, terminating inferiorly in an oblique, 88 GENERA OF SHELLS. sub -channelled emargination. Columella flat- tened, terminating at base in a point. The purpura is distinguished by the dilated aperture, and the flattened and generally naked columella, ter- minating in a point at the base, whose notch turns a little upwards posteriorly. P. Persica, Rudolphi, patula, columellaris, succincta, con- sul, armigera, bitubercularis, hippocastanum, undata, lia?ma&- toma, mancinella, bufo, callosa, neritoides, planospira, callifera, coronata, carinifera, scalariformis, sacellum, squa- mosa, rugosa, textilosa, sertum, Francolinus, limbosa, ligata, cruenta, lapillus, imbricata, lagenaria, cataracta, bicostalis, plicata, fiscella, thiarella, rustica,semi-imbricata, echinulata, hystrix, deltoidea, unifascialis, retusa, trochlea, clavus, fasciolaris vexillum, bizonalis, nucleus. MONOCEROS. Shell oval. Aperture longi- tudinal, terminating inferiorly by an oblique sinus ; a conic tooth at the base of the lip internally. The only distinguishing character between the mo- noceros and purpura, is the projecting, horn shaped conical tooth, on the right lip, which is constant in all species. M. imbricatum, striatum, glabratum, crassilabrum. CONCHOLEPAS. Shell ovate, inflated, semi- spiral ; summit inclined obliquely to the left margin. Aperture ample, longitudinal, ob- lique, with a slight emargination below. Two teeth at the base of the lip. Operculum ob- long, thin, horny. GENERA OF SHELLS. 89 This shell was formerly placed with the patellae ; but on account of the notch at the lower part of the aperture, and from its having an operculum, it differs materially. C. Peruvianus. HARPA. Shell oval, more or less inflated, having parallel, longitudinal, inclined, com- pressed and acute ribs. Aperture emarginated inferiorly ; without a canal. Spire short. Columella smooth, flattened, and pointed at base. H. imperialis, ventricosa, conoidalis, nobilis, articularis, rosea, minor, striata, mutica. DOLIUM. Shell thin, ventricose, inflated, generally subglobular, rarely oblong, trans- versely banded. Lip dentate or crenulate throughout. Aperture oblong, emarginate in- feriorly. The dolium is distinguished from the harpa, terebra, eburna, &c.by having no longitudinal ribs, by their in- flated, ventricose, subglobular form, the spire being much shorter than the lower whorl, whence the aper- ture is very large, and occupies more than two thirds the length of the shell. They are thin, and attain a large size. They are all encircled by transverse bands, which render the margin of the lip crenate throughout. D. galea, olearium, maculatum, fasciatum, pomum, varie- gatum, perdix. BUCCINUM. Shell ovate or ovate-conic. Aperture longitudinal, having at base a notch, 90 GENERA OF SHELLS. without a canal. Columella not flattened, turgid above, undate curved. The buccina are marine shore shells, the greater part very small, though some obtain a medium size. Those which have a callous columella were separated into a distinct genus called nassa, which has since been reunited to buccinum. B. undatum, glaciale, Anglicanum, papyraceum, annula- tum, Ia3vissimum, testudineum, achatinum, glans, papillo- 8um, olivaceum, canaliculatum, crenulatum, reticulatum, Tranquebaricum,lineatum,fuscatum,lineolatum,maculosum, politum, suturale, rnutabile, inflatum, retusum, ventncosum, gemrnulatum, Coromandelianum, fasciatum, miga, lyratum, tricarinatum, Brasilianum, semiconvexum, fasciolatum, vin- osum, tenuiplicatum, subspinosum, Ascanias, Ia3vigatum, flexuosum, aciculatum, corniculatum, cribrarium, grana, coccinella, zebra, dermestoideum, aurantium, pediculare, — ornaturn, armigerum, bezoar. Columella callous, (Nassa.) B. arcularia,coronatum, Ther- sites, gibbulosum, pullus, marginulatum, pauperatum, poly- gonatum, neriteum, — vibex, trivittata, obsoleta, acuta, unicincta, alba, lunata. EBURNA. Shell oval or elongated ; lip per- fectly simple. Aperture longitudinal, emar- ginate at base. Columella urnbilicated at its upper part and channelled below the umbilicus. Distinguished from buccinum by the singular posi- tion of the umbilicus, of the columella, which is also produced so as to form a canal, which occupies the rest of the left lip. E. glabrata, zeylanica, spirata, areolata, lutosa. TEREBRA. Shell elongated, turreted, very GENERA OF SHELLS. 91 acute at summit. Aperture longitudinal, much shorter than the spire, emarginate posteriorly at base. Base of the columella twisted or ob- lique. The very short columella of this shell presents a peculiar character ; in its general form it much resem- bles the turritella, but is distinguished by its aperture, and by the notch at the posterior part of the base ; from eburna by not having the channelled umbilicus, and from buccinum by the small proportion which the length of the aperture bears to the spire. T. maculata, flammea, crenulata, dimidiata, muscaria, subulata, oculata, duplicata, Babylonia, corrugata, Senega- lensis, coerulescens, striatula, chlorata, cerithina, raphanula, cingulifera, myuros, scabrella, strigilata, lanceata, aciculina, granulosa, vittata. COLUMELLARIA. JY*0 canal at the base of the aperture, but a more or less dis- tinct subdorsal notch, and plaits on the columella. COLUMBELLA. Shell oval, spire short. Base of aperture more or less emarginate ; no canal. Columella plaited. Outer lip dilated inter- nally, narrowing the aperture. The shells of this genus are short, small, and of con- siderable thickness, often striated transversely and of various colors. They are distinguished from volutaby the swelling on the inside of the outer lip and by hav- ing an operculum. C. strombiformis, rustica, mercatoria, flavida, semipunc- tata, bizonalis,reticulata, hebraea, pardalina,scripta, ovulata, 9*2 GENERA OF SHELLS. nitida, fulgurans, mendicaria; turturina, punctata, unifascia- lis, zonalis, — labiosa, avara. MITRA. Shell turreted or subfusiform ; spire pointed at summit ; base emarginated, without a canal. Columella with parallel, transverse plaits, the inferior of which are the smallest. Pillar lip thin, adnate. Distinguished from the voluta, by the summit of the spire being quite pointed, and not terminated by a mammella, and by the columellar plaits gradually les- sening towards the base. The columellar lip is some- times visible only near the base of the columella. M. episcopalis, pnpalis, pontificalis, puncticulata, mille- pora, eardinalis, archiepiscopalis, A?ersicolor, sanguinolenta, ferruginea, terebralis, adusta, granulosa, crocata, casta, nex- ilis, olivaria, scabriuscula, gnmatina, crenifera, serpentina, toeniata, piicaria, corrugata, costclluris, lyrata, melongena, cincteHa, vulpecula, cafFra, sanguisuga? stigmataria, filosa, fissurata, lactea, eornicularis, lutescons, striatula, subulata, cornea, tringa, melaniana, scutulata, dactylus, fencstrata, crenulata, texturata, conulus? Urnbtfera, aurantiaca, ampho- rella, coronata, paupcrcula, cucumerina, patriarchalis, iimri- culata, torulosa, ebenus, harpaefbrntis, semifasciata, retusa, microzonias, ficulina, nucleola, unifascialis, bacillurn, conu- lariSj arenosa, clavulus, litterata, Peronii, obliquata, plumbea, larva, pisolina, dermestina, grariulifera, oniscina, tabanula, pediculus. VOLUTA. Shell oval, more or less ventri- cose, summit obtuse or mammilJary, emarginate at base and without a canal. Columella plaited, the inferior folds largest and most ob- lique. No pillar lip. GENERA OF SHELLS. 93 The volutae are distinguished from the mitrse by the lower plaits on the columella being larger than the upper, and by the obtuse and mammellated termination of the spire. (a.) Shell ventricose, inflated. (Cymbiola.) V. nautica, diadema, armata, ducalis, tessellata. JEthi- opica, melo. Neptuni, cymbium, olla, proboscidalis, porcina, scapha, Brasiliana. (b.) Shell oval, spiny or tuberculous. (Muricina.) V. imperialis, pellis serpentis, vespertilio, mitis, nivosa, serpentina. (c.) Shell oval, subtuberculous. (Musicales.) V. hebroea, musica, chlorosina, thiarella, carneola, Guini- aca, laevigata, polyzonalis? fulva, sulcata, nodulosa. (rf.) Shell elongate, ventricose, almost fusiform. (FusoideaJ) V. magnifica, ancilla, Magellanica, Pacifica, fulminata, Junonia, undulata, Lapponica, vexillum, valvacea, festiva. mitraBformis, nucleus. MARGINELLA. Shell ovate oblong, smooth; spire short ; outer lip with a thickened margin. Aperture subemarginate at base. Columella plaited ; folds subequal. The marginellse are smooth, polished shells, and remarkable for the varix on the right lip. They are distinguished from voluta by the equal folds on the columella, by the aperture which occupies almost the whole length of the shell, by the callus on the right lip, and by the scarcely perceptible notch at the base of the aperture. (a.) Spire prominent. M. glabella, radiata, nubeculata, ccerulescens, quinquepli- cata, limbata, rosea, bifasciata, faba, aurantia, bivaricosa, 94 GENERA OF SHELLS. longivaricosa, muscaria, fornicula, eburnea, dentifera, ovu- lata. (b.) Spire not prominent. M. dactylus, bullata, cornea, avellana, persicula, lineata, tessellata, interrupta. VALVARIA. Shell cylindrical, convolute ; spire scarcely exserted. Aperture narrow, as long as the shell. Columella with one or more folds at its inferior part. Distinguished from nrmrginella by having in general, no varix on the outer lip, which is thin and sharp, though sometimes slight traces of a varix are percepti- ble. They are generally small shells. V. monilis, pallida, triticea, oryza, miliacea, bulloides, canaliculata. CONVOLUTA. Shell icithout a canal, but emarginate or effuse at base; whorls large, compressed, turned in such a manner that the last almost entirely envelopes the others. OVULA. Shell inflated, attenuated or sub- acuminated at the two extremities ; mar- gins turned inwards. Aperture longitudinal, narrow, effuse at extremities. Pillar lip, not toothed. The ovulse are closely allied to the cyprsea in form ; are sometimes rostrated at both ends, nearly smooth, and have no spire. They are distinguished from them by the left lip never having any indentations, and from bullse by the turning inwards of the right lip. (a.) Outer lip dentate, with folds. O. oviformis, angulosa, verrucosa, lactea, carnea, triticea, hordacea. GENERA OF SHELLS. 95 (&.) Outer lip smooth. O. gibbosa, acicularis, spelta, birostris, volva. CYPRJEA. Shell oval or oval-oblong, convex, margins turned inwards. Aperture longitu- dinal, narrow, both lips toothed, effuse at both extremities. Spire very small, scarcely ap- parent. The shell assumes a very different appearance at dif- ferent periods of growth. When young the aperture is dilated especially at the lower part, is entirely with- out indentations, and the right lip is short. In the mid- dle stage of growth it acquires the general form of the adult shell, but it has only its first layer of testaceous matter, and the spire, though very small, is not en- tirely covered, and its colors are still wanting. Without attention to the varying form of the shell according to age, we shall be liable to make three distinct species of the same individuals. Sometimes the spire presents a little pit, like an umbilicus ; sometimes both the mar- gins are dilated, sometimes only one and sometimes neither are prominent or inflated. C. cervina, exanthema, argus, testudinaria, Mauritiana, mappa, Arabica, histrio, scurra,rattus, stercoraria, mus, ven- triculus, aurora, tigris, tigrina, talpa, carneola. lurida, vilelius, caput-serpentis, cinerea, zonata, sordida, icterina, miliaris, variolaria, rufa, lynx, adusta , erosa, caurica, isabella, ocellata, cribraria, turdus, olivacea, stolida, hirundo, undata, zigzag, flaveola, sanguinolenta, poraria, ursellus, asellus, moniliaris, stercus-muscarum,cicercula, lota.globulus, ovulata, helvola, arabicula, staphylea, pustulata, nucleus, limacina, moneta, obvelata, annulus, radians, oniscus, pediculus, oryzge, coccinella, australis, albella. 96 GENERA OF SHELLS. TEREBELLUM. Shell convolute, subcylin- drical, summit acute ; aperture longitudinal, narrow above, emarginate at base. Columella smooth, truncated inferiorly. The terebellum has no epidermis ; it is thin, smooth and when we look at its back, appears to be irregularly notched at the base. It most resembles the ancillaria, oliva and conns, and has a slight likeness to the young cypraea. T. subulatum, convolutum, fusiforme. ANCILLARIA. Shell oblong, subcylindrical ; spire short, not channelled at sutures. Aper- ture longitudinal, scarcely emarginated at base, effuse, a callous, oblique varix at base of col- umella. The ancillaria greatly resembles the oliva, but the upper edges of the whorls of the spire rest, each of them, against the preceding whorl and are not separated by a spiral canal, as in oliva. The callous, oblique varix distinguishes this genus from terebellum and buccinum. The aperture is longitudinal, but never extends the whole length of the shell. N. cinnamonea, ventricosa, marginata, Candida. OLIVA. Shell subcylindrical, convolute, smooth ; spire short, sutures channelled. Aperture longitudinal, emarginate at base. Columella obliquely striate. O. porphyria, textilina, erythrostoma, pica, tremulinay angulata, maura, sepulturalis, fulminans, irisans, elegans,. episcopalis, venulata, guttata, leucophaea, reticularis,, flam- GENERA OF SHELLS. 97 mulata, granitella, araneosa, litterata, scripta, tricolor, sanguinolenta, mastelina, lugubris, funebralis, glandiformis,- Peruviana, Senegalensis, fusiformis, undata,inflata,bicincta, harpularia, hepatica, ustulata, avellana, tessellata, carneola, ispidula, oriola, Candida, volutella, tigrina, Brasiliana, utricu- lus, auricularia,acuminata, subulata, luteola, testacea, hiatula, obtusaria, Zeilanica, nebulosa, fabagina, conoidalis, unda- tella, eburnea, nana, zonalis, oryza, — mutica. CONUS. Shell turbinate or inversely conic, convolute. Aperture longitudinal, narrow, not toothed, effuse at base. The olivse are distinguished from the cylindrical cones, by the channel which separates the whorls of the spire and by the striae on the columella; from voluta and mitra by the spiral whorls of those shells being separated by simple unchannelled sutures. It has also a prominent callus at the upper end of the columellar lip, which assists in forming the channel of the spire. (1.) Shell crowned. C. marmoreus, bandanus, nocturnus, Nicobaricus, araneosus, zonatus, imperialis, fuscatus, viridulus, regius, cedonulli, aurantius, nebulosus, minimus, sulcatus, hebrgeus, vermicu- latus, arenatus, pulicarius, fastigatus, obesus, varius, tulipa, geographus, punctatus, ta3nia(us, musicus, miliaris, mus, lividus, Barbadensis, roseus, cardinalis, Magellanicus, distans, pontificalis, Caledonicus, sponsalis, puncturatus, Ceylanicus, lamellosus, pusillus, exiguus, asper. (2.) Shell not crowned. C. millepunctatus, litteratus, eburneus, tessellatus, gener- alis, Maldivus, Malacanus, lineatus, monile, centurio, vitu- linus, vulpinus, flavidus, virgo, daucus, pastinaca, capita- neusjclassiarius, vittatus, mustelinus, vexillum, Sumatrensis, 7 98 GENERAOFSHELLS. hyoena, miles, ammiralis, genuanus, papilionaceus, Siamensis, prometheus, glaucus, Suratensis, monachus, ranunculus, anemone, achatinus, cinereus, stramineus, zebra, lacteus, cingulatus, vicarius, mercator, ochraceus, betulinus, figuli- nus, quercinus, proteus, leoninus, .augur, pertusus, nivosus, fulgurans, acuminatus, amadis, Janus, flammeus, litho- glypbus, testudinarius, venulatus, qusestoi, muscosus, narcis- sus, Mozambicus, Guinaicus, Franciscanus, inforrnis, rattus, Jamaicensis, mediterraneus, puncticulatus, Mauritianus, fu- migatus, eques, Luzonicus, catus, verrucosus, acutangulus, mindanus, Japonicus, pusio, columba, Madurensis, nemoca- nus, cancellatus, fusiformis, ccerulescens, aurora, Taitensis, Adansonii, Tinianus, Portoricanus, crocatus, amabilis, Omai- cus, nobilis, aurisiacus, terminus, striatus, gubernator, granulatus, terebra, verulosus, raphanus, magus, spectrum, bullatus, cervus, stercus-muscarurn. Tirnorensis, nimbosus, dux, tendineus, pra3fectus, melancholicus, strigatus, glans. mitratus, nussatella, aulicus, auratus, colubrinus, clavus, auricomus, omaria, rubiginosus, pennaceus, praelatus, panni- culus, archiepiscopus, canonicus, episcopus, abbas, Jegatus textile, pyramidalis, gloria maris, australis. ORDER IV. ~- CEPHALOPODA. The shells of those cephalopoda which are furnished with them, afford but little instruc- tion from their form, as to that of the animals which produced them. To distinguish these shells we can only compare them with one another, and we are as yet ignorant whether the divisions we may thus establish will coin- cide with the principal divisions we should form of the mollusca themselves, if we had the opportunity of being better acquainted with them. GENERA OF SHELLS. 99 SECT. I.— POLYTHALAMOUS CEPHALAPODA. Shell multilocular, wholly or partly developed, inserted in the posterior part of the body of the animal , of ten adhering. ORTHOCERATA. Shell straight or nearly so ; no spiral. Most of the shells of this family are unknown except in the fossil state. BELEMNITES. Shell straight, elongated, conical, formed of two distinct and separable parts ; viz. external, a solid sheath, filled at the upper part, with a conical cavity ; internal, a conical nucleus, pointed, chambered trans- versely through its whole length, multilocular ; chambers slightly concave on one side, and convex on the other, and perforated by a central siphon. The belemnites, which are only found fossil and generally empty, or without the nucleus, are merely the sheath of an elongated-conical mass, not adhe- ing, chambered, and furnished with a siphon like the orthocera and hippurites. ORTHOCERA. Shell elongate, straight or slightly arcuated, subconic, striated externally by numerous longitudinal ribs. Chambers formed by transverse partitions perforated by a tube, either central or marginal. O. raphanus, fascia, raphanistrum, obliqua, acicula, legumen, NODOSARTA. Shell elongate, straight, or 100 GENERA OF SHELLS. slightly arcuated, subconic, with smooth nodes. Chambers formed by transverse partitions^ perforated either at the centre or near the margin. N. radicula, dentalina,rsiphunculus. HJPPURITES. Shell tubular, cylindrico-coni- cal, straight or slightly curved, thick, multilo- cular ; septa transverse. An internal, lateral canal, formed by two longitudinal, obtuse, converging edges. The last chamber closed by a thick, solid operculum ; edges of the operculum bevelled, and accurately adjusted to the orifice of the chamber. Fossil. CONOLITES. Shell conical, straight, slightly bent ; sheath thin, distinct from the contained nucleus* Nucleus sub-separable, multilocular, divided by transverse septa. The conolites appears to differ from the helemmteg, principally in not having the upper portion of the sheath, or external shell, elongated and solid, (in con- sequence of the termination of the cavily for the nu- cleus before it reaches the summit) as in those shells. LITUOLATA. Shell partly spiral ; the last whorl straight. SPIRULA. Shell cylindrical, thin, nearly transparent, multilocular; partially turned into a discoid spiral ; whorls- distant ; the last pro- duced into a right line. Partitions transverse, GENERA OF SHELLS. 101 equidistant, concave without, with a lateral, interrupted siphon. Aperture orbicular. S. Peronii, — (Nautilus spirula, Lin.) SPIROLINITES. Shell multilocular, partly twisted into a discoidal spiral; whorls con- tiguous, the last terminating in a straight line. Septa transverse, perforated by a tube. Distinguished from spirula by the contiguity of the whorls. Only known in the fossil state ; very small shells. LITUOLITES. Shell multilocular, partly twisted into a discoidal spiral ; whorls con- tiguous, the last terminating in a straight line. Chambers irregular, septa transverse, simple, (no siphon) ; the last septum pierced with from three to six holes. Small fossil shells ; the septa which form the cham- bers are at unequal distances, and inclined to one another; some species have scarcely one complete turn of the spiral. CRISTATA. Shell semi-discoidal ; spire eccentric. RENULITES. Shell kidney-shaped, flattened, furrowed, multilocular ; chambers linear ; con- tiguous, curved round a marginal axis ; those farthest from the axis the longest. One fossil species. CRISTELLARIA. Shell semidiscoid, multilo- 102 GENERA OF SHELLS. cular ; whorls contiguous, simple, progressive- ly enlarging. Spire eccentric, sublateral, septa im perforate. C. squammula, papillosa, leevis, auricularis, faba, scapha, crepidula, auricula, tuberosa. ORBICULINA. Shell subdiscoidal, multilo- cular ; whorls contiguous and compound ; spire eccentric. Chambers short, very numer- ous ; septa imperforate. O. numismalis, anguJata,uncinata. SPH^ERULATA. Shell globular, spheroidal, or oval ; whorls of the spire en- veloping, or the chambers united under one covering. MILLIOLITES. Shell transverse, oval-glob- ular or elongated, multilocular. Chambers transverse, surrounding the axis, and succes- sively covering one another ; aperture very small, situated at the base of the last whorl, orbicular, or oblong. Lamarck states that he possesses specimens in a recent state, which are found on fuci,'near the Island of Corsica ; but all the species he describes are fossil. The size of these tiny shells scarcely exceeds that of grains of millet, whence their name ; some are globu- lar, inclining to oval, others oblong, or somewhat triangular. MELONITES. Shell subspherical, multilocu- lar ; spire central ; whorls contiguous, en- GENERA OF SHELLS. 103 veloping. Chambers narrow, elongated and numerous ; septa imperforate. RADIOLATA. Shell discoidal, spire central ; chambers elongated, radiating from the centre to the circumference. From the character of the shells of this family, it follows that their spire can have but one turn, and is consequently false or imperfect. ROTALITES. Shell orbicular, spiral, convex or conoidal at the upper part ; flattened, radiating, and tubercular at the lower ; multi- locular. Radii wavy ; aperture marginal, tri- angular, inclined towards the base. The rotalites are very small shells, widest at' the base, with the whorls contiguous and distinct. LENTICULITES. Shell sub-lenticular, spiral, multilocular ; exterior margin of the whorls triplicate, extending over the interior whorls, both above and below, to the centre of the shell. Septa entire, curved, produced on both sides like radii. Aperture narrow, projecting over the penultimate whorl. The lenticulites are distinguished from the rotal- ites and discorbites, by the lateral prolongation of the chambers and septa, and from the nautilus by not having the siphon. They are similar to nummulites, but differ by the prolongation of the chambers and by the projection of the aperture over the penultimate whorl. They are chiefly fossil, but Lamarck tells us 104 GENERA OF SHELLS. that he possesses some species which are found in the sea near Teneriffe, at the depth of 125 feet. PLACENTULA. Shell orbicular, convex above and below, multilocular. Aperture oblong, narrow, disposed as a ray in the inferior disc, or on both discs. P. pulvinata, asterisans. NAUTILACEA. Shell discoidal, spire central, chambers short, not extending from the centre to the circumference. The nautilacea differ from the radiolata, in having the spire composed of several whorls, wherefore the chambers cannot extend from the centre to the cir- cumference ; their spire is also complete, which that of the radiolata never is. DISCORBITES. Shell discoidal, spiral, mul- tilocular ; sides simple. All the whorls visible, naked, contiguous to one another. Septa transverse, frequent, imperforate. The discorbites differs from the nautilus, by having all the whorls of the spire visible and no siphon ; from rotalites, by the aperture not inclining downward to- wards the base, and the spire not rising into a cone. SIDEROLITES. Shell multilocular, discoidal ; whorls contiguous, not visible externally ; disc convex on both sides, and loaded with tuber- cular points ; circumference bordered with unequal, radiating lobes. Septa transverse, imperforate. Aperture distinct, sublateral. GENERA OF SHELLS. POLYSTOMELLA. Shell discoidal, multilocu- lar ; whorls contiguous, not apparent exter- nally, radiated exteriorly by striae or costae running in the direction of the whorls. Aper- ture of many holes variously disposed. These characters are common also to the lenticulites, but the aperture of the latter is simple, whilst that of the polystomella is composed of several holes, differ- ently disposed in different species. P. crispa, costata, planulata, ambigua. VORTICIALIS. Shell discoidal, spiral, multi- locular ; whorls contiguous, not apparent ex- ternally ; septa transverse, imperforate, not extending from the centre to the periphery. Aperture marginal. The vorticialis differs from nummulites chiefly by having a distinct aperture, and from discorbites, by the spiral whorls not being visible externally. Their axis is central and confounded with the summit of .the spire. V. craticulata, strigilata, marginata. NUMMULITES. Shell lenticular, attenuated towards the edges ; spire internal, discoidal, multilocular, covered with several thin plates ; exterior side of the whorls triplicate, extending from both sides to the centre of the shell and uniting. Chambers very numerous, small, al- ternate ; septa imperforate, transverse. 106 GENERA OF SHELLS. NAUTILUS. Shell discoidal, spiral, multilo- cular ; parietes simple ; whorls contiguous, the last enveloping the others. Chambers numer- ous. Septa transverse, concave without ; disc perforated by a tube ; margins quite simple. N. pompilius, umbilicatus. AMMONEATA. Septa sinuous, loled and indented at the circumference, united at the inner surface of the shell and articulating with it by means of indented sutures. AMMONITES. Shell discoidal, spiral, whorls contiguous, and all of them visible ; the inte- rior parietes articulated by sinuous sutures. Septa transverse, lobed and indented at the circumference ; their discs without any siphon, but perforated by a sort of marginal tube. The ammonites differ essentially from the nautili by the sinuous sutures of the internal parietes and by the similarly sinuous form of the septa ; from the or- bulites, by all the whorls being distinctly visible. They are only found in a fossil state. ORBULITES. Shell sub-discoidal, spiral, whorls contiguous, the last enveloping the rest ; internal parietes articulated by sinuous sutures. Septa transverse, lobed at the cir- cumference, and perforated by a marginal tube. AMMONOCERATITES. Shell horn shaped, GENERA OF SHELLS. 107 nearly semicircular ; parietes articulated by sinuous, branch-like, indented sutures. Septa transverse, sinuous, lobed and indented at the circumference. Tube or siphon marginal, not perforating the septa. TURRILITES. Shell spiral, turreted, multi- locular, whorls contiguous, all visible ; parietes articulated by sinuous sutures. Septa trans- verse, lobed and indented at the circumference. Aperture rounded. The turrilites, instead of being discoidal, or simply arched, are elongated, straight, and form a very ele- vated spiral, which it seems, must terminate in a point like the turritella. BACULITES. Shell straight, cylindrical, sometimes slightly compressed, rather conical; parietes articulated by sinuous sutures. Septa transverse, near together ; disc of the septa imperforate, lobed and indented at the circum- ference. The chambers of these shells are transverse and narrower than those of the turrilites. SECT. II.— MONOTHALAMOUS CEPHALOPODA. Shell unilocular, wholly external and envelojring the animal. ARGONAUTA. Shell univalve, unilocular, involute, very thin ; spire bicarinate, tubercu- lous, re-entering the aperture. A. argo, tuberculosa, nitida. 108 GENERA OF SHELLS. SECT. III.— NAKED CEPHALOPODA . The, animals of this section have no shell either internal or external, but the greater number of them contain a solid, free, cretaceous or horny substance in the interior of their body. SEPIARTA. The sepiaria are marine animals, none of them have any true shell ; they always live in the sea, some crawl- ing at the bottom, as the octopus ; others, as the sepia and loligo, swimming freely in the water, by means of membranes or fins with which their sac is furnished. This family contains four genera, OCTOPUS, LOLIGOPSIS, LOLIGO, SEPIA. ORDER V. — HETEROPODA. The body is gelatinous and transparent and the shell of some of them resembles that of the argonauta. CARINARIA. Shell univalve, conical, com- pressed at the sides, unilocular, very thin, hyaline ; apex spiral ; back sometimes with a dentated carina. Aperture oblong, entire. C, vitrea, fragilis, cymbium. PTEROTRACHEA and PHYLLIROE, have no shell. GLOSSARY. ABBREVIATED, shortened Abrupt, terminating suddenly Accessory (valves), small addi- tional ones Acute, sharp pointed, or edged Adherent, fixed to rocks and other solid bodies Adnate, growing firmly together Alveolate, having large cells Annulate, marked with rings Area, or Anterior Flope, that on which the ligament is placed Areola, or Posterior £lope, the side of the beaks opposite to the liga- ment Apex, or Vertex, the point at which the shell commences Apophysis, an excrescence, a pro- jection Approximate, approaching near each other Arcuated, simply curved like an arch Arenaceous, of a sandy consistence Attenuated, tapering to a point Auricular, or Auriculated, with ear-like appendages BASE, the extremity opposite the apex Beaks, the summit of bivalves Bifid and Bipartite, divided at the tip Body, the last and largest whorl of a univalve Byssus, filaments by which the animal adheres to foreign bodies CALCAREOUS, of the nature of lime Callus, or Callosity, an elevation of the enamel above the surface, about the aperture Cardinal (teeth) under the apex or beaks Carinate, like the keel of a vessel Caudate, or Caudiform, a tail like process Cicatrix, impressions where the muscle is fixed Clavate, club shaped Columella, the pillar or axis Connate, parts soldered together Contorted, twisted Connivent, converging or ap- proaching Convoluted, rolled upon itself Cordate, or Cordiform, heart shaped Corselet, the depression anterior to the beaks Coriaceous, of leather-like con- sistence Corneous, resembling horn Crenate, or Crenulate, scolloped at the margin Cretaceous, chalky Crustaceous, like the shell of a lobster Cuneiform, wedge shaped DECORTICATED, with the outer skin removed Decussated, crossing at right angles Deltoid, like a triangle Dentated, toothed Denuded, destitute of covering Diaphanous, transparent Diaphragm, an interior transverse division Diffuse, spreading Digitate, like fingers Discoidal, like a wheel or pulley Disc, convex part of bivalves be- tween the umbones and margin Divaricate, or Divergent, spread- ing like a fan Dorsal, on the back ECHIPIATED, set with spines Effuse, the lips separated by a gutter 110 GLOSSARY. Emarginate, notched Epidermis, the membranous cov- ering of a shell Equilateral, the sides equal Equivalve, the valves equal and similar Escutcheon, vide Corselet Eroded, appearing as if gnawed Exserted, protruded FACET, the flat summit of the in- ferior valve Falciform, sickle shaped Fixed, attached — vide Adherent Flexuous, alternately bent and nearly straight Fluviatile, inhabiting rivers or fresh water Foramen, a hole or opening Foliaceous, resembling leaves Fossa, a cavity to receive a tooth Fusiform, spindle shaped GIBBOUS, bulging out Geminate, in pairs HYALINE, transparent like glass IMBRICATE, one over another, like tiles In, (in composition) has a nega- tive power Involute, rolled inwards LABIUM, the columellar lip Labrum, the outer lip Lamella, or Lamina, a thin layer or scale Lenticular, like a lens Ligament, the substance which connects the valves Limbus, circumference of the valves Linear, with parallel sides Lunated, crescent shaped Lunule, or Anus, the depression behind the beaks MAMMILLA, a nipple-like protuber- ance ' Multilocular, with many cells or chambers Multivalve, with more than two valves NACRE, like pearl Nates, vide IJmbo Nucleus, the layer of the shell, first formed Nymphae, or Labia, the ridges to which the ligament is attached OBSOLETE, indistinct, worn away by age Operculum, the lid which closes the aperture Osseous, like bone PARIETES, the walls or sides Patulous, spreading open, gaping Papyraceous, like paper Pectinated, like the teeth of a comb Pedicle, or reduncle, the fleshy support of the Lepas Penultimate, the last but one Posterior slope, vide Areola Pyriform, pear shaped QUADRATE, somewhat square RINGENT, saping Rostrum, the elongated canal of univalves SECURIFORM, hatchet shaped Septum, a partition Sessile, fixed, without a pedicle Sinus, an excavation or gutter Sinuate, indented, irregular mar- gin Siphon, a tube passing through the chambers of Nautilus, &c. Squamose, scaly Striae, thread-like lines Sub, (in composition) means ap- proaching to, nearly Subulate, awl shaped Sulcus, a groove or furrow Summit, the tip or apex Suture, the lines between the whorls TESTACEOUS, of the materials which form shells Tortuous, twisted, winding Tridentate, three toothed Truncated, cut off square Tubercle, a small eminence Turbinated, shaped like a top nearly conic UMBILICUS, perforation in the cen- tre of a univalve, visible under- neath Umbo, the most prominent part near the beak Univalve, with one valve VA RICES, prominences, at the stages of growth Ventricose, swelling in the middle Vertex, the tip of the spire or umbo WHORL, a revolution of the spire ERRATA. — Page 68, 4 lines from top, for spine read spire. " 94, for Valvaria read Volvaria. RETURN TO the circulation desk ot any University of California Library or to the NORTHERN REGIONAL LIBRARY FACILITY Bldg. 400, Richmond Field Station University of California Richmond, CA 94804-4698 ALL BOOKS MAY BE RECALLED AFTER 7 DAYS • 2-month loans may be renewed by calling (510)642-6753 • 1-year loans may be recharged by bringing books to NRLF • Renewals and recharges may be made 4 days prior to due date. DUE AS STAMPED BELOW JAN 2 2 1997 HETUKNtD MAR *