A Conchological Manual by George Brettingham Sowerby (best interesting books to read txt) 📕

   CREPIDULINA. Bl. CRISTELLARIA, Lam. Microscopic.

   CRESEIS. Ranz. _Order_, Pteropoda, Lam.--_Descr._ Thin, fragile,

   transparent, pyramidal, pointed; with a dorsal ridge produced into a

   point at the edge of the aperture.--_Obs._ The species found in the

   Mediterranean is named C. Spinifera (fig. 222), from its resemblance to

   a thorn.

   CREUSIA. Leach. (_Creux_, se. Fr. a cavity.) _Fam._ Balanidea, Bl.

   _Order_, Sessile Cirripedes, Lam.--_Descr._ A depressed cone,

   consisting of four valves, supported upon, and jointed to, a cup-shaped

   cavity formed in the Madrepores, in which it resides. Aperture

   quadrilateral, closed by an operculum of four valves.--_Obs._ This

   genus is distinguished from Pyrgoma, which is supported on the edge of

   a similar cup-shaped cavity, by the paries being composed of four

   valves, whereas in Pyrgoma, it consists of a single piece. Fig. 28, C.

   Gregaria. East Indies.

   CRICOSTOMATA. Bl. The second family of Asiphonibranchiata, Bl. It is

   thus described: "shell equally (with the animal) variable in general

   form, but of which the aperture, always nearly round, is completely

   closed by the shelly or horny operculum; whorls few, and apex

   sublateral." This family agrees in some measure with the family

   Turbinacea of Lamarck, and with the genus Turbo in the system of

   Linnæus. It contains the genera Pleurotomaria, Delphinula, Turritella,

   Proto, Scalaria, Vermetus, Siliquaria, Magilus, Valvata, Cyclostoma,

   and Paludina.

   CRIOCERATITES. A genus composed of species of Ammonites, with

   disconnected whorls. C. Duvallii, fig. 482.

   CRIOPUS. Poli. CRANIA, Auct.

   CRISTACEA. Lam. The third family of Polythalamous Cephalopoda, Lam.

   This family is described as including shells of the following

   characters:--"Multilocular, flattened, nearly reniform; the chambers

   gradually increasing in length, as they approach the outer arched

   margin, and appearing to revolve round an eccentric, more or less

   marginal axis. The Cristacea contain the genera Renulina, Cristellaria,

   and Orbiculina."

   CRISTACEA. Bl. The third family of Polythalamia, Bl. containing the

   genera Crepidulina, (Cristellaria, Lam.) Oreas and Linthuris.

   CRISTARIA. Schum. DIPSAS Plicatus, Leach. ANODON tuberculatus, Fer.

   CRISTELLARIA. Lam. CREPIDULINA, Bl. _Fam._ Cristacea, Lam. and

   Bl.--_Descr._ Semidiscoidal, chambered; whorls contiguous, enlarging

   progressively; spire eccentric, sublateral; septa imperforate.

   Microscopic.

   CRYPTA. Humph. CREPIDULA, Lam.

   CRYPTELLA. Webb. ([Greek: Kruptô], to conceal.) TESTACELLUS Ambiguus of

   Ferrusac. Published in Sowerby's Genera of Shells as PARMACELLA

   calyculata.--_Descr._ A small patelliform shell, with a very short

   papillary spire; and the aperture irregularly expanded. Fig. 256.

   Canary Islands.

   CRYPTOCONCHUS. Bl. A genus composed of species of Chiton, the valves of

   which are covered by the integument, as Chiton porosus of Burrows. Ch.

   amiculatus of Pallas.

   CRYPTODIBRANCHIATA. Bl. The first order of the class Cephalophora, Bl.

   containing families of molluscous animals destitute of shells.

   CRYPTOSTOMA. Bl. Differs from SIGARETUS, Lam. principally in the soft

   parts of the animal. De Blainville remarks that he is acquainted with

   only two species (from the Indies), which he can with decision refer to

   the genus, but he thinks that many of the Lamarckian Sigareti may very

   probably be found to belong to it, as soon as the soft parts shall be

   known. The species which he figures is Cryptostoma Leachii. (Manuel de

   Malacologie, pl. 42. fig. 3.)

   CTENOCONCHA. Gray. Described as having many characters in common with

   the Solens, the teeth like Nucula, but the cartilage entirely external.

   SOLENELLA, Sow.?

   CUCULLÆA. Lam. (_Cucullus_, a hood.) _Fam._ Arcacea, Lam.--_Descr._

   Sub-quadrate, nearly equivalve, sub-equilateral, deep; hinge

   rectilinear, with a series of angular teeth, small near the umbones,

   larger and more oblique towards the extremities; umbones separated by a

   flat external area, on which the ligament is spread. Anterior muscular

   impression produced into a sharp-edged plate or ledge, projecting from

   the side of the shell. Posterior muscular impression flat and

   indistinct.--_Obs._ This genus very much resembles Arca in general

   form, but differs in the oblique, lengthened character of the remote

   teeth, and in the singularly prominent edge of the muscular impression.

   China. Fig. 133, C. Auriculifera.

   CUCUMIS. Klein. MARGINELLA, Auct.

   CULTELLUS. Species of LUTRARIA, Lam. which have the umbones placed near

   the extremity of the shell. _Ex._ L. Solenoides, fig. 78.

   CUMA. Humph. FUSUS and FASCIOLARIA, Lam.

   CUMINGIA. Sow. _Fam._ Mactracea, Lam.--_Descr._ Equivalve,

   inequilateral, transverse, rounded anteriorly, subrostrated

   posteriorly. Hinge with a central spoon-shaped cavity in each valve,

   containing the cartilage; a very small anterior cardinal tooth in each

   valve; two lateral teeth in one valve, none in the other: muscular

   impressions two in each valve, distant; palleal impression with a very

   large posterior sinus.--_Obs._ The species known at present are found

   in sand, in the fissures of rocks in Tropical climates. They resemble

   Erycina in general form and character, but differ in having the

   internal cartilage placed in a prominent spoon-shaped process, while

   that of Erycina is contained in a hollow which sinks under the umbones.

   This genus should be placed near Amphidesma. Cumingia mutica, fig. 87.

   CUNEIFORM. (_Cuneus_, a wedge.) Wedge-shaped, as Donax, fig. 108.

   CUNEUS. Megerle. VENUS Meroe, Linn. and similar species.

   CUNICULA. Sw. A sub-genus of Uniones, thus described:--"Ovate, oblong;

   bosses thick, but depressed; cardinal teeth moderate. C. planulata,

   patula, rubiginosa, secura, purpurascens."

   CURVED. Arched or bent. _Ex._ Dentalium, fig. 2.

   CURVULA. Rafinesque. A fossil imperfectly described as differing from

   Pinna, in being inequivalve.

   CUVIERIA. Ranz. (Baron Cuvier.) _Class_, Pteropoda, Lam.--_Descr._

   Thin, transparent, glassy, cylindrical, rounded and inflated at the

   closed extremity, compressed towards the opening, so as to render it

   oval. This genus differs from Vaginula in being rounded, instead of

   pointed, at the lower extremity. Mediterranean. Fig. 223, C. Columella.

   CYCLAS. Brug. _Fam._ Conques Fluviatiles, Lam. Conchacea, Bl.--_Descr._

   Orbicular, thin, subovate, ventricose, sub-equilateral, equivalve;

   cardinal teeth minute, one more or less complicated in the left valve,

   two diverging in the right; lateral teeth elongated, compressed,

   laminar, acute, doubled in the left valve; ligament external; epidermis

   thin, horny.--_Obs._ The Cyclades are viviparous, and abound in

   ditches, ponds, slow streams, &c. in Europe and North America. The

   genus Pisidium has been separated on account of a difference in the

   animal, and may be known from Cyclas by being less equilateral, and the

   anterior side being the longest. Fig. 111, C. Rivicola.

   CYCLOBRANCHIATA. Bl. The third order of the second section of

   Paracephalophora Monoica, Bl. containing no genera of Testaceous

   Mollusca.

   CYCLOCANTHA. Sw. A genus of "Trochidæ," consisting of Turbo stellaris

   and T. Calcar, and corresponding with the genus Calcar, Montf.

   CYCLONASSA. Sw. A genus of "Nassinæ," Sw. consisting of Nassa

   Neritoidea, and corresponding with the genus Cyclops, Montf.

   CYCLOPHORUS. Montf. A generic name proposed for those species of

   Cyclostoma, Auct. which have an umbilicus. C. Involvulus, fig. 304,

   would be the type of this genus.

   CYCLOPS. Montf. NASSA Neritoidea, Auct. fig. 424.

   CYCLOSTOMA. Auct. ([Greek: kuklos], _cyclos_, round; [Greek: stoma],

   _stoma_, mouth.) _Fam._ Colimacea, Lam. Cricostomata, Bl. A genus of

   land shells varying in shape from that of Pupa to that of a flat orb;

   the aperture is generally circular and the peritreme uninterrupted,

   thickened and sometimes reflected, the operculum is shelly and spiral.

   Two other genera of land shells are provided with opercula, and

   consequently might be confounded with this genus. In Helicina, the

   operculum is concentric and the peritreme is not continuous; while in

   the small genus hitherto almost unknown of Pupina, the peritreme is not

   continuous and there is a glassy enamel over the whole of the external

   surface. In the plates we have represented, C. ferrugineum, fig. 303;

   CYCLOTUS. Guild. A sub-genus of Cyclostoma, consisting of those species

   which are discoidal, as C. Planorbulum. Fig. 530.

   CYLINDER. Montf. CONUS textile, Auct. (fig. 461) and other species

   having a cylindrical form.

   CYLINDRELLA. Sw. A genus of the family "Ovulinæ," Sw. composed of

   cylindrical species of Ovulum? The wood-cut illustrating this genus has

   the appearance of a Bulla.

   CYLINDRICAL. ([Greek: kulindros], a cylinder.) This like other

   mathematical terms is used with great latitude by Conchologists, and

   applied to any shell the sides of which are nearly parallel, with the

   extremities either rounded, flat, or conical. _Ex._ Oliva, fig. 457.

   CYLLENE. Gray. _Fam._ Purpurifera, Lam.--_Descr._ Oval, thick, with a

   short acute spire; an oval aperture terminating anteriorly in a slight

   emargination, posteriorly in a short canal; a fold at the lower end of

   the body whorl; outer lip thick, striated within; angle of the whorls

   tuberculated.--_Obs._ This genus of small marine shells resembles

   Voluta in general character, but differs in having a smooth columella

   without folds. Recent, Pacific Ocean; Fosil, London clay. Fig. 425.

   CYMBA. Brod. (_Cymba_, a boat or skiff.) _Fam._ Columellaria,

   Lam.--_Descr._ Smooth, ventricose, with a very short, mammillated, rude

   spire; and a very large, wide aperture, terminated anteriorly in a deep

   emargination; posteriorly in a flat ledge, which separates the outer

   lip from the body whorl; columella with three or four oblique, laminar,

   projecting folds, terminating in a point; outer lip thin, with its edge

   sharp; epidermis smooth, brown, covered partly or entirely by the

   glassy enamel, which, commencing with the outer lip, spreads over the

   body of the shell.--_Obs._ These very elegant shells, found in Africa,

   are distinguished from the true Volutes by the shapeless, mammillated

   apex of the short spire, by the large size of the aperture, and by the

   horizontal ledge which separates the outer lip from the body whorl. The

   genus Melo, also separated by Mr. Broderip from the Volutes, agrees

   with Cymba in some respects, but differs in the regularity of the

   spire. Fig. 434, C. Porcina.

   CYMBIOLA. Sw. The generic name for a group of Volutes, described as

   "armed with spinous tubercules, sometimes smooth, but never ribbed;

   spiral whorls gradually diminishing in size, but not distorted; apex

   thick and obtuse; pillar with four plaits." Mr. Swainson remarks that

   this genus is chiefly distinguished by the obtuse, but not irregular

   spire. The typical species are stated to be V. Rutila and V.

   Vespertilio, fig. 433. Tropical.

   CYMBULIA. (Dim. from _Cymba_.) _Fam._ Pteropoda, Lam. An extremely

   light, cartilaginous covering of a molluscous animal, so named from its

   similarity in shape to a boat. We mention it here on account of its

   similarity to the shelly or glassy covering of other Pteropods, to

   which, although membranaceous, it is evidently analogous. The Cymbuliæ

   are found in the Mediterranean.

   CYPRÆA. Auct. _Fam._ Enroulées, Lam. Angyostomata, Bl.--_Descr._ Oval

   or oblong, ventricose, convolute, covered by an enamel, generally

   smooth and shining. Spire short, nearly hid. Aperture long, narrow,

   terminating in a short canal at both extremities. Outer lip dentated,

   thickened, inflected. Inner lip dentated, thickened, reflected over

   part of the body whorl.--_Obs._ These shells are so distinguished by

   the two rows of teeth arranged on each side of the aperture; the

   thickened front formed by the inner and outer lips; and the enamel

   deposited over the back of the shell from the mantle of the animal

   which envelopes it, that there is no danger of confounding them with

   any other genus, except in a young state. Before they have arrived at

   the full growth, the front is not thickened, and the outer lip is thin,

   not inflected, nor are the teeth formed. In this state the shell

   resembles, in some degree, an Oliva. Some species are striated, ribbed,

   or tuberculated, but the generality are smooth. Most species belong to

   tropical climates, only one to Great Britain. The C. Moneta is current

   as money in some parts of Africa, and many species are worn as

   ornaments by the South Sea Islanders. The colouring in most species is

   exceedingly rich, and arranged in every variety of spots, patches,

   rings, lines, bands and clouds. The species most esteemed by collectors

   are C. Mappa, C. Testudinaria, C. Pustulata, C. Aurora, C. Princeps, of

   which only two specimens are known, C. Leucodon, &c. See also

   Cypræovulum, Trivea and Luponia. The fossil species are principally

   from the Calc-grossier, the London Clay, Crag, &c. Fig. 445 to 450. The

   latest revision of this genus has been effected by Mr. G. B. Sowerby,

   sen., who has published a complete catalogue in his son's Conchological

   Illustrations. This catalogue enumerates 130 species, the whole of

   which are figured in parts 1 to 8, 101 to 131 of the above mentioned

   work.

   CYPRÆCASSIS. Stutch. (Cypræa and Cassis.)--_Descr._ Shell, when young,

   striated,