Part 7

_Shell._ With an epidermis, subequivalve, equilateral, depressed, elongated, truncated anteriorly; the summit median and posterior; no trace of ligament; a long fibro-gelatinous peduncle fixing the shell vertically to submarine bodies; muscular impression multiple. Inhabits the Indian Ocean. One species.

Lingula anatina.

CLASS IV. MOLLUSCA.

Animals soft, inarticulated, furnished with an anterior head, projecting or salient; most frequently with eyes and tentaculæ, or possessing, at their summit, arms disposed in the form of a coronet: their mouth either short, elongated, or tubular, exsertile, and generally armed with hard parts. Mantle diversified, having its edges free on the sides of the body, or the lobes united, forming a sack, which in part envelopes the animal; gills or respiratory organs various, circulation double, one particular, the other general; heart unilocular, sometimes with the auricles divided, and very distant; no medullary cord along the body, but scattered nerves and ganglions. Twenty-two families.

FAMILY I.

PTEROPODA. Six genera.

Some genera of this family are without a testaceous covering, mentioned only to preserve the family entire.

1. Genus _Hyalæa_. Pl. IX.

_Animal._ Body enclosed in a shell, winged before, two opposite wings, somewhat retractile, inserted at the sides of the mouth, head distinct, mouth terminal, placed at the junction of the fins; without eyes.

_Shell._ Symmetrical, very thin and transparent, valves unequal, flat above, convex below, open like a cleft anteriorly, summit truncated and tridentated posteriorly. Inhabits the Mediterranean. Two species.

Hyalæa tridentata. H. cuspidata.

2. Genus _Clio_. Pl. IX.

_Animal._ Body free, naked, more or less elongated, tapering to the rear, head very distinct; provided with six, long, conical, retractile tentaculæ, separated into two groups of three each; mouth altogether terminal and vertical, eyes sessile, rudiment of a foot under the neck.

This is a molluscous animal without any testaceous covering, but is here placed as leading to other genera which have shells. Inhabits the Indian seas. Two species.

Clio borealis. C. Australis.

3. Genus _Cleodora_. Pl. IX.

_Animal._ Body oblong, gelatinous, contractile; a head in front with two wings, and the posterior part enveloped in a shell, head distinct, projecting and round; two eyes; mouth in the form of a small beak; destitute of tentaculæ; two, opposite, membranaceous, pellucid, and cordated wings, placed at the base of the neck.

_Shell._ Pyramidal, triangular, of a gelatinous or cartilaginous substance, very thin and transparent; aperture obliquely truncated. Inhabits the South American seas. Two species.

Cleodora pyramidata. C. caudata.

4. Genus _Limacina_. Pl. IX.

_Animal._ Body soft, oblong, two branchial fins situated at the base of the neck; posterior part of the body spiral, and enveloped in a shell.

_Shell._ Thin, fragile, papyraceous, spiral, the whorls reunited in a planorbis form, and deeply and largely umbilicated on one side; aperture large and entire. Inhabits the North seas. One species.

Limacina helicialis.

5. Genus _Cymbulia_. Pl. IX.

_Animal._ Body oblong, gelatinous, pellucid, enclosing a shell; head sessile; two eyes, and two retractile tentacula; mouth with a retractile proboscis; two, opposite, oblong, ovate, branched wings, connate at their posterior base.

_Shell._ Gelatinous, cartilaginous, very transparent, crystalline, oblong, in shape of a shoe, from which it has derived the name of the slipper, truncated at the summit; aperture lateral and anterior. Inhabits the Mediterranean. One species.

Cymbulia Peronii.

6. Genus _Pneumodermon_. Pl. IX.

A molluscous animal, without any testaceous covering, and much resembling the genus Clio. Inhabits the Indian seas. One species.

Pneumodermon Peronii.

FAMILY II.

PHYLLIDIACEA. Six genera.

1. Genus _Phyllidia_. Pl. IX.

A mollusca similar to the preceding genus, without a shell, but its back covered with a rough or coriaceous skin. Inhabits the Mediterranean. Three species.

Phyllidia varicosa. P. pustulosa. P. ocellata.

2. Genus _Chitonellus_. Pl. IX.

_Animal._ Body creeping, elongated; middle of the back provided its entire length with a detached, multivalve shell; the alternate pieces for the most part longitudinal; sides naked; branchiæ disposed around the body; foot cleft longitudinally by a deep furrow.

_Shell._ Each valve with striæ radiating from its apex; the margins serrated; the base of the last valve obtuse. The testaceous plates of this genus are never joined like those of the Chiton, so that the animal can move in every direction. Upon the contraction of the animal after death, however, these valves become nearly united. Inhabits the seas of New Holland. Two species.

Chitonellus striatus. C. larvæformis.

3. Genus _Chiton_. Pl. IX.

_Animal._ Body creeping, ovate oblong, convex, round at both extremities; marginated with a coriaceous skin: the back covered by a longitudinal series of testaceous, transverse, imbricated, and moveable plates; head before, sessile, with the mouth placed below, destitute of tentacula or eyes; branchiæ placed round the body, under the margin of the skin; and orifice at the posterior extremity.

_Shell._ Eight imbricated valves, nearly smooth, slightly carinated, and rounded at the margins: summit more or less marked and curved by longitudinal elongations. Inhabits the British and American coasts. Sixty-three species.

Chiton fulvus. C. pisceus. C. ruber. C. lævis. C. spinosus. C. fascicularis. C. marginatus. C. crinitus. C. siculus. C. niger. C. spiniferous. C. coquimbensis. C. lumingii. C. granosus. C. glauco-sinctus. C. disjunctus. C. elegans. C. lineatus. C. sulcatus. C. bicolor. C. cerasimus. C. Magellanicus. C. marmoratus. C. nebulosus. C. olivaceous. C. latus. C. punctatus. C. viridus. C. cinerus. C. tunicatus. C. gigas. C. squamosus. C. Peruvianus. C. tesselatus. C. capensis. C. Carmichaelis. C. echinatus. C. striatus. C. lineolatus. C. chilensis. C. tuberculatus. C. hispidus. C. thalassimus. C. porosus. C. larvaformis. C. undulatus. C. luteolus. C. fuscus. C. minimus. C. cimex. C. ascellus. C. Icelandicus. C. fasciatus. C. setosus. C. variegatus. C. asselloides. C. indus. C. albas. C. castaneus.

· · · · ·

C. Emersonii.* C. fulminatus.* C. amœna.* C. alternata.* C. sagrinatus.*

4. Genus _Patella_. Pl. IX.

_Animal._ Body completely covered by the shell; head with two acute tentaculæ, and the eyes situated at their exterior base; branchiæ placed under the mantle and around the body.

_Shell._ This numerous and beautiful genus of Linnæus has been subdivided into the several distinct genera of Fissurella, Emarginula, Navicella, Umbrella, Pileopsis, Calyptrea, Crepidula, Parmophora, and Ancylus; each of which possesses sufficiently well-defined characters to authorize a separation, by which they may be more easily distinguished from the still widely extended family of Patella. Oval, conic, or a little depressed, outside green or brown, sometimes radiated with various colours; having divergent striæ and concentric wrinkles, inside glossy, iridescent, with yellow or fawn-coloured, purple, blue, or brown radiations. Inhabits almost every coast. Forty-nine species.

Patella safiana. P. testitudinaria. P. cochlear. P. compressa. P. granularis. P. decaurata. P. Magellanica. P. stellifera. P. vulgata. P. mammillaris. P. lineata. P. leucopleura. P. notata. P. Tarentina. P. punctata. P. puncturata. P. Javanica. P. tuberculifera. P. miniata. P. pellucida. P. tricostata. P. Australis. P. apicina. P. granatina. P. oculus. P. Galathia. P. pectinata. P. viridula. P. scutellar. P. radians. P. cærulea. P. plumbia. P. umbrella. P. pyramidata. P. luteola. P. aspera. P. spinifera. P. longicosta. P. barbata. P. angulosa. P. saccharina. P. laciniosa. P. plicata.

· · · · · P. amœna.* P. alternata.* P. alveus.* P. candida.*

5. Genus _Umbrella_. Pl. IX.

_Animal._ Body very thick and oval, provided with a dorsal shell; foot large, smooth, and flat, surrounded by a border, anteriorly notched, attenuated behind; head indistinct; four tentacula, the two upper ones thick, short, and truncated, the other two thin, and shaped like pedunculated crests; having foliaceous branchiæ.

_Shell._ External, orbicular, subirregular, nearly flat, slightly convex above, white, with apex near the middle; margin acute, internal surface rather concave; having a callous disk, coloured, depressed in the centre, surrounded by a smooth border. Inhabits the Indian Ocean. Two species.

Umbrella Indica. U. Mediterranea.

6. Genus _Pleurobranchus_. Pl. IX.

_Animal._ Body creeping, fleshy; mantle and foot expanded; branchiæ placed on the right side; cloak enveloping the shell; neck short, contracted in some species, with an emarginate front, exhibiting the commencement of the inferior tentacula, the upper ones tubular and cloven; gills at the edge of the dorsal plait, mouth provided with a short, retractile proboscis.

_Shell._ Depressed, oval, oblong, concentrically wrinkled, almost entirely open, rounded and convoluted; the vertex with a single turn. Inhabits the coast of Devonshire in England. Two species.

Pleurobranchus Peronii. P. Laqueare.

FAMILY III.

CALYPTRACEA. Seven genera.

1. Genus _Parmophorus_. Pl. IX.

_Animal._ Body creeping, thick, oblong-ovate, broad behind, obtuse at the extremities; border of the mantle cleft before, and suspended vertically around; head distinct, and slit below; two conical contracted tentacula, at the base of which are placed the eyes, which are somewhat pedunculated; mouth below, funnel-shaped, oblique, truncated, and concealed; branchial cavity opening anteriorly behind the head by a transverse fissure.

_Shell._ Oblong, very depressed, slightly convex above, obtuse at extremities, anteriorly channeled by a slight sinus, and having towards the posterior part a small pointed apex, inclined backwards; the lower surface slightly concave. Inhabits the Australian seas. Four species. One fossil.

Parmophorus Australis. P. brevicula. P. granulata. P. ambigua.

2. Genus _Emarginula_. Pl. IX.

_Animal._ Body creeping, with two, conical, tentacular eyes at the external base; mantle large, partly covering the margin of the shell; foot very large and thick.

_Shell._ Shield-like, conical; summit inclined; the cavity simple, having a notch or hollow cut on its posterior margin; shells of this genus are generally very small. Inhabits the British seas. Five species.

Emarginula Blainvillii. E. Cuvierii. E. fissura. E. rubra. E. marginata.

3. Genus _Fissurella_. Pl. IX.

_Animal._ With the head truncated in front; two conical tentacula, with eyes at their exterior base; mouth simple, terminal, and destitute of jaws; two pectinated branchiæ projecting from the cavity; mantle large, protruding beyond the shell.

_Shell._ Shield-shaped, conical recurved, summit entire, depressed, concave below, perforated at the summit in the form of a key hole, without a spire; the exterior surface ribbed longitudinally. Inhabits the European and American seas. Twenty-two species.

Fissurella Cayennensis. F. lilacina. F. Javanicensis. F. fascicularis. F. rosea. F. Barbadensis. F. radiata. F. nodosa. F. nimbosa. F. crassa. F. Græca. F. picta. F. pustula. F. hiantula. F. viridula. F. depressa. F. Peruviana. F. gibberula. F. minuta. F. plicata.

· · · · ·

F. alternata.* F. redimicula.*

4. Genus _Pileopsis_. Pl. X.

_Animal._ With two conical tentacula, and the eyes at their base; branchiæ formed in a row under the anterior margin of the cavity, near the neck.

_Shell._ Obliquely conical, anteriorly recurved, apex bent, almost spiral; aperture rounded, elliptical, the anterior margin shortest, acute, slightly sinuated; the posterior largest and rounded. One elongated and arched muscular impression, situated under the posterior margin. Inhabits the seas of Europe. Nine species.

Pileopsis intorta. P. subrufa. P. spirirostris. P. retortella. P. ungarica. P. mitula. P. pennata. P. squamæformis. P. depressa.

5. Genus _Calyptrea_. Pl. X.

_Animal._ The same as preceding genus.

_Shell._ This genus derives its common name, “the Cup-and-Saucer Limpit,” by having in the interior cavity a cup-shaped appendage, which is sometimes vertical, and sometimes like a horse-shoe, with a muscular impression of variable form, vertex ending in a small volution; smooth, margin entire, very glossy within, and provided with a laminar plate. Inhabits the Chinese and S. American seas. Nine species.

Calyptrea porcellana. C. equestris. C. fornicata. C. peziza. C. angulata. C. tecum-sinense. C. scutellata. C. poculum.

· · · · ·

C. striata.*

6. Genus _Crepidula_. Pl. X.

_Animal._ Head anteriorly forked, having two conical tentacula, with the eyes placed at their exterior base; mouth simple, destitute of jaws, and situated in the bifurcation of the head; branchiæ with tufts and projecting from the branchial cavity; the mantle never bordering the shell; foot minute, orifice lateral.

_Shell._ Ovate, or oblong; the back almost always convex, concave beneath; the spire very much inclined towards the margin; the aperture partly closed by a horizontal lamina. Inhabits the American seas. Thirteen species.

Crepidula extinctorum. C. aculeata. C. lævigata. C. uguiformis. C. dilata. C. Peruviana. C. gigas.

· · · · ·

C. fornicata.* C. depressa.* C. glauca.* C. plana.* C. intorta.* C. convexa.*

7. Genus _Ancylus_. Pl. X.

_Animal._ Body creeping, enveloped in the shell; two compressed subtruncated tentacular, with eyes situated at their internal base; foot short, elliptical; somewhat narrower than the body.

_Shell._ Thin, obliquely conical; aperture oval, with a pointed apex, which very much inclines backwards; margins simple. This is a fresh water shell, found in the lakes of Europe and rivers of America. Five species.

Ancylus lacustris. A. fluviatilis. A. spinarosæ.

· · · · ·

A. rivularis. A. filosus.

FAMILY IV.

BULLACEA. Three genera.

1. Genus _Acera_.

_Animal._ Body ovate, convex, transversely divided above into two parts; the foot with dilations in the form of wings below; head indistinct; branchiæ situated on the back, greatly behind, and covered by a mantle destitute of a shell. Inhabits the Mediterranean. One species.

Acera carnosa.

2. Genus _Bullæa_. Pl. X.

_Animal._ Body ovate, somewhat convex above, and divided into two parts transversely; lateral lobes of the foot very thick; head indistinct, and without tentacula; branchiæ placed on the back.

_Shell._ Concealed in the mantle, very thin, rolled and spiral on one side; without a columella and spire; aperture very large and wide, dilated at the upper part. Inhabits the British seas. Two species.

Bullæa aperta. B. striata.

3. Genus _Bulla_. Pl. X.

_Animal._ Body oblong-ovate, slight convexity; divided into two portions transverse above, mantle slightly folded posteriorly; visible tentacula; branchiæ dorsal and covered, opening only on the right side.

_Shell._ Univalve, ovate globular, convolute, no columella, spire not projecting but visible, aperture the whole length of the shell, external margin sharp and smooth. Inhabits the British and American seas. Nineteen species.

Bulla physis. B. naucum. B. hydatis. B. rugosa. B. fragilis. B. aplustre. B. ampulla. B. lignaria. B. fasciata. B. striata. B. Wyatii. B. solida. B. cornea. B. lactea.

· · · · ·

B. solitaria.* B. triticea.* B. hiemalis.* B. Gouldii.* B. lineolata.*

FAMILY V.

APLYSIACEA. Two genera.

1. Genus _Dolabella_. Pl. X.

_Animal._ Body creeping, oblong, narrowed in front; and posteriorly widened; area round, sloping, and truncated obliquely; margins folded over the back; four tubular tentacula, disposed in pairs; bronchial operculum inclosing a shell; orifice dorsal, near the branchiæ.

_Shell._ Oblong, slightly arcuated, thick, callous, and somewhat spiral on both sides, singular in formation, and its characteristic unlike most other shells. Inhabits the Isle of France. Two species.

Dolabella Rumphii. D. fragilis.

2. Genus _Aplysia_. Pl. X.

_Animal._ Body creeping, oblong, convex above; bordered on each side by a broad mantle, which covers the back when the animal is in repose; head and neck elevated, with four tentacula, the two upper ones ear-shaped, eyes situated near the mouth; dorsal shield semicircular, subcartilaginous, adhering on one side, and covering the branchial cavity.

_Shell._ Nearly round, left margin somewhat reflected; outer lip acute; yellowish horn colored, with brown radiations, and two concentric bands. Inhabits the Indian seas. Thirty-seven species.

Aplysia depilans. A. teremida. A. gigas. A. hassetlii. A. punctata. A. marmorata. A. dolabrifera. A. ascifera. A. petalifera. A. unguifera. A. Limacina. A. Jeachii. A. saviguana. A. fasciata. A. bresili. A. dactycomela. A. protea. A. sorex. A. tigrina. A. maculauta. A. longicauda. A. Kerandrenii. A. lessonii. A. camelus. A. alba. A. Napolitana. A. viridis. A. longicornis. A. ecaudata. A. virescens. A. poliana. A. fusca. A. pleii. A. citrini. A. undata. A. rosea. A. Ferrusacii.

FAMILY VI.

LIMACINA. Five genera.

1. Genus _Limax_. Pl. X.

_Animal._ Cuvier merely mentions that the animal is “furnished with a coriaceous, subrogose shield, with a flat, longitudinal disk beneath; four tentacula retractile, eyes at the tips; orifice for respiration on the right side.”

_Shell._ Ovate oblong, both margins reflected; very thin, diaphanous, slightly wrinkled, of a pale yellow colour. Inhabits the gardens in Britain and France. Five species.

Limax rufus. L. cinerus. L. albus. L. agrestis. L. punctata.

2. Genus _Vitrina_. Pl. X.

_Animal._ Body creeping, elongated, snail shaped, nearly straight; posteriorly separated from the foot, and spirally wound into a shell.

_Shell._ Small, very thin, depressed, terminated above by a very short spire, the last whorl very large; aperture large, rounded oval; the left margin arched, slightly involute. Inhabits dry places of Europe. Three species.

Vitrina parilis. V. dentilis. V. pellucida.

3. Genus _Testacella_. Pl. X.

_Animal._ Body creeping, elongated, snail shaped, having a shell placed on the posterior extremity; four tentacula, the two longest with their eyes at their tips; respiratory organs behind.

_Shell._ Very small, external, ear-shaped, apex absolutely spiral, aperture very large and oval, left edge sharp and rolled inward behind. Inhabits the middle provinces of France. Two species.

Testacella Haliotidea. T. Neritoidea.

4. Genus _Parmacella_. Pl. X.

_Animal._ Body creeping oblong; middle of the back moderately convex, and shield-shaped; hind part in form of a tail, laterally compressed, acute above; shield ovate, fleshy, adhering at its posterior part, free before, enveloping a shell, with a notch in the centre of its right margin; four tentacula, two posterior largest; respiratory organs, under the notch of the shield, placed between the two tentacula of the right side.

_Shell._ Ovate, left margin broad and reflected; right margin reflected at top and acute beneath; very thin and pellucid, of a pale yellowish-brown. Inhabits the gardens of Europe. Two species.

Parmacella Olivieri. P. Cuvierii.

5. Genus _Onchidium_. Pl. X.

_Animal._ Body oblong, creeping, marginated on all sides; head projecting, the lower part with a prominent margin, two retractile, cylindrical tentacula; two auriform appendages, nearly lateral; mouth beneath, destitute of maxillary processes; respiratory orifices distinct, under the extremity of the body.

Destitute of a shell. Inhabits the gardens of Europe. Two species.

Onchidium Typhæ. O. Peronii.

FAMILY VII.

COLIMACEA. Eleven genera.

1. Genus _Helix_. Pl. X.

_Animal._ Of a slightly variable form, the mantle forming at its free edge a kind of ring or thick collar, especially in front, and faintly divided into two lips; foot oval, plane, smooth beneath, inflated and granular below, joined to the visceral club by a narrow peduncle; head sufficiently distinct; anterior tentacula very evident and inflated at top, the posterior very long; the mouth a vertical cleft provided with two labial lobes, a sort of marginal tooth, with a small, oval, lingual club.

_Shell._ The name Helix was given to this genus from the spiral shape of the shell, which varies much in form, but generally globular, and ventricose, conoid but never turriculated; summit generally obtuse, aperture varying much in size, sometimes very large, sometimes small, always regulated by the turn of the spire; oval, semilunar, more wide than long, edges disunited, entering little into the interior; right lip or margin thickened or reflected inwards. Inhabits the groves and woods both of America and Europe. Two hundred and three species.

Helix vesicalis. H. gigantea. H. polyzonalis. H. monozonalis. H. pulla. H. lineolata. H. mutata. H. pomatia. H. aspersa. H. vermiculata. H. Alonensis. H. vesicolor. H. naticoides. H. picta. H. galactites. H. cepa. H. heteroclites. H. discolor. H. lactea. H. zonaria. H. guttata. H. Madagascarensis. H. Javanica. H. Peruviana. H. simplex. H. cidaris. H. citrina. H. algira. H. verticellus. H. olivetorum. H. hæmastoma. H. melanotragus. H. extensa. H. lucana. H. globulus. H. melanostoma. H. cœlatura. H. microstoma. H. maculsa. H. Richardi. H. Bonplandii. H. planulata. H. labrella. H. unguina. H. pellis-serpentis. H. senegalensis. H. unidentata. H. fructicum. H. neglecta. H. crespitum. H. ericetorum. H. intersecta. H. Carthusianella. H. diaphana. H. concolor. H. velutina. H. obvuluta. H. Cookiana. H. pileus. H. papilla. H. punctifera. H. plicatula. H. planorbella. H. scabra. H. cariosa. H. crenulata. H. planorbula. H. macularia. H. planospira. H. Barbadensis. H. sinuata. H. hippocastanum. H. bidentalis. H. argilacea. H. vittata. H. arbustorum. H. candidissima. H. memoralis. H. Hortensis. H. sylvatica. H. pisana. H. splendida. H. serpentina. H. niciensis. H. variabilis. H. auriculata. H. turgidula. H. helicella. H. zonula. H. tridentata. H. septemvalva. H. monodan. H. fraterna. H. coniformis. H. concamerata. H. nigrescens. H. Tripolitana. H. Sayii. H. globulosa. H. Caffra. H. conformis. H. prunum. H. Pouzolzii. H. contusa. H. bicarinata. H. vitrinoides. H. maritima. H. strigata. H. muralis. H. rugosa. H. cornea. H. liquifera. H. incarnata. H. cinctella. H. cellaria. H. Gaymardii. H. nitidia. H. plebuim. H. personata. H. hispidia. H. rotundata. H. apicina. H. striata. H. conspurcata. H. conica. H. conoidea. H. pulchella. H. formosa. H. orbiculata. H. squamosa. H. tectiformis. H. Madeirensis. H. unbeculata. H. deformis. H. Nicæensis. H. meridionalis. H. melitensis. H. circumornata. H. gronosa. H. Lima. H. dentiens. H. parilis. H. imperator. H. zodiaca. H. concisa. H. pellicuta. H. strobilus. H. alanda. H. carina. H. Bulverii. H. pileolus. H. vipartita. H. sinistrorsa. H. fibula. H. supplicata. H. Porto-santara. H. punctulata. H. exalbida.

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