Part 27

5. POTAMOPHILA. Two thick cardinal teeth. Fig 115.

Marine.

1. CYPRINA. Two cardinal teeth, and one remote lateral tooth. Fig. 116.

2. VENUS. Three cardinal, no lateral teeth; including Artemis. Fig. 118, 119, 119a.

3. CYTHEREA. Several cardinal teeth; one very short lateral tooth. Fig. 117, 117a, 117b, 117c, 117d.

4. PULLASTRA. Cardinal teeth notched, otherwise like Venus. Fig. 120.

5. ASTARTE. Three cardinal teeth; ligament short. Fig. 110.

VENERICARDIA belongs to the Cardiacea.

CONCHIFERA. Lam. The 11th class of Invertebrata, consisting of all those animals which have bivalve shells. Lamarck divides the class into Dimyaria, which have two adductor muscles; and Monomyaria, which have but one.

CONCHOLEPAS. Montf. (CONCHA, a shell; lepas, a stone or rock.) Fam. Purpurifera, Lam. Entomostomata, Bl.--Descr. Oval, imbricated, thick; with a very short spire and large oval patelliform aperture, terminating anteriorly in a slight emargination; outer lip crenated, with two produced points or teeth towards the anterior, inner lip smooth, nearly flat, reflected over the last whorl, so as nearly or entirely to cover it; operculum horny. Marine, only one species known, from Peru.--Obs. This shell is placed near Patella by Lamarck, on account of its large open aperture; but having a horny operculum, and resembling Purpurea in other respects. Fig. 418. Concholepas Peruviana.

CONCHOTRYA. Gray. (Concha, a shell; [Greek: Truo], (tryo) to bore.) Order, Pedunculated Cirripedes, Lam.--Descr. Five pieces, two pairs ventral, one single; shaped like Pentelasmis. Found in holes.

CONCHYLIOMORPHITE. A term used by De Blainville to designate the cast or model of a fossil shell, formed by a siliceous substance which has entered or surrounded it when in a liquid state, and subsequently become hardened into flint. The shell has afterwards decomposed or fallen off by accident, leaving its external or internal characters to be conjectured from the monumental impressions that remain.

CONCHYTA. Hupsch Mus. CALCEOLA, Lam.

CONE. A common name for shells of the genus Conus.

CONE. This mathematical term is used by conchologists in its utmost latitude of signification to express a body, which in its formation, commences in a small point, called the apex, and increases in width towards the conclusion or base. It is applied to all shells, whether the increase in width be gradual or sudden; or whether in its growth, it takes a straight, oblique, curved, or spirally-twisted course. In this sense, a bivalve would be described as a pair of rapidly enlarging, oblique cones, and the aperture of every spiral shell would be its base. But this phraseology being in disuse, it is only mentioned here that it may be understood when occasionally met with.

CONELLA. Sw. A genus composed of species of the genus Columbella, Lam. which have a conical form, and which, on that account, are considered by Swainson as belonging to his family of Coninæ. Swains. Lardner. Cyclop. Malac. described at p. 312. C. picata, Sw. fig. 17, a. p. 151.

CONFLUENT. A term applied to two parts of a shell when they gradually flow into each other, as, for instance, the inner and outer lips of Univalves when they pass into each other at the anterior extremity, without the intervention of a notch or angle.

CONIA. Leach. Fam. Balanidea. Order, Sessile Cirripedes, Lam.--Descr. Four rather irregular valves, of porous structure, placed side by side, so as to form a circular cone, supported at the base on a shelly plate, and closed at the aperture by an operculum consisting of four valves in pairs. Distinguished from Creusia by its porous structure and by its flat support; that of Creusia being cup-shaped. Fig. 21, Conia porosa.

CONICAL. A term applied in the ordinary sense, and not as explained above, under the word CONE.

CONIDEA. Sw. A genus separated from Columbella, Lam. thus described, "Mitra shaped, fusiform; spire equal or longer than the aperture; the whorls tumid; outer lip slightly gibbous above, contracted below; margin not inflected; striated within; inner lip terminating in an elevated ridge, but with the teeth obsolete. C. semipunctata, (Columbella, Lam.) Mart. 44. fig. 465, 466." Africa.

CONILITES. Fam. Orthocerata, Lam. & Bl.--Descr. "Conical, straight or slightly curved; having a thin external covering, independent of the nut or alveole, which it contains. Alveole transversely chambered, sub-separable." (Translated from Lam.)--Obs. The difference between Belemnites and Conilites is that the external sheath of the latter is thin, and not filled up with solid matter, from the point of the alveole to the apex, as in the former. De Blainville places in this genus the genera Thalamulus, Achelois and Antimomus, Montf. two of which are figured, Knor. Sup. Fab. iv. fig. 1. 1. 8. 9. Conilites Pyramidatus, fig. 470.

CONILITHES. Sw. A sub-genus of Coronaxis, Sw. (Coni, with coronated whorls) thus described, "Conic; spire considerably elevated; the aperture linear, C. antediluvianus, Sow. Gen. f. 1."

CONOHELIX. Sw. (Conus and Helix.) The generic name given to those species of Mitra which are conical in form. Fig. 432, C. marmorata.

CONOPLÆA. Say. Order, Sessile Cirripedes, Lam. A genus composed of Balani, attached to the stems of Gorgonia, having their bases elongated. Ex. fig. 27, Balanus Galeatus.

CONORBIS. Sw. A genus composed of species of CONUS, such as C. dormitor, (Sowerby, gen. fig. 8) which have elevated spires and the upper part of the outer lip deeply sinuated. Mr. Swainson considers these fossil species as analogous to the Pleurotomæ. Sw. Lard. Cyclop. Malac. p. 312.

CONOVULUM. A genus proposed by Lamarck, to include the small, conical species of Auricula, which have the outer lip simple. This genus was afterwards abandoned by the author. Ex. fig. 298, Auricula coniformis.

CONTIGUOUS. (Contingo, to touch.) A term applied to the whorls of spiral shells when they rest upon, or touch each other. This is the case in a great majority of instances. When, on the contrary, there is a space between the whorls, they are said to be non-contiguous, detached, or free. Examples of non-contiguous whorls are to be seen in Scalaria, fig. 351 (in this case, the distance between the whorls is small), and in Crioceratites, fig. 482. A "Columella contiguous to the axis," is when in the centre of the shell and takes the place of the imaginary line which forms its axis.

CONTINUOUS. Carried on without interruption, as the siphon in Spirula, the varices in Ranella, fig. 394, which, occurring in a corresponding part of each whorl, form a continuous ridge.