Part 28

CONULARIA. Miller. A genus of Orthocerata, described as conical, straight, or nearly so, divided into chambers by imperforate septa; aperture half closed; apex solid, obtuse; external surface finely striated. Resembling Orthoceras, but wanting the siphon. Fig. 449.

CONUS. Auct. ([Greek: Kônos], a cone.) Fam. Enroulées, Lam. Angyostomata, Bl.--Descr. Conical, convolute, with a short spire, consisting of numerous whorls; and narrow lengthened aperture, terminating in a slight emargination at each extremity; outer lip thin; epidermis thin; operculum small, pointed, horny.--Obs. This well-known genus of shells is easily distinguished from any other, by its conical form, its smooth columella, its narrow aperture, and thin outer lip. The form of the spire varies from flat and even partially concave, to a regular pyramidal cone; and the upper edges of the whorls are rounded in some species, angulated in others, and in some are waved or coronated. The variety of marking and the numerous delicate tints of these shells have caused them to be highly appreciated by amateur collectors; and many species, as the C. Ammiralis, or admiral; the C. Gloria Maris, or Glory of the Sea; the C. Cedonulli ("I yield to none"), and others, have always produced good prices in the markets. We give figures of the principal forms, as expressed in the genera proposed by De Montfort, of Rhombus, Hermes, Rollus and Cylinder, in figures 459 to 462. Many new species were brought to this country by Mr. Cuming, and are represented in parts 24, 25, 28, 29; 32, 33, 36, 37; 54, 55, 56, 57; 147, 148; 151 to 158 of the Conchological Illustrations, by G. B. Sowerby, jun. See CORONAXIS, Swainson. The cones are mostly tropical, some are found as far north as the Mediterranean, and south as the Cape of Good Hope. The most beautiful species are from the East and West Indies.

CONVOLUTÆ. (Enroulées, Lam.) A family of the 2nd section of the order Trachelipoda, Lam. the genera of which may be distinguished as follows:--

1. CYPRÆA. Lips thickened, inflected, with teeth; spire hidden, including Cypræovulum, Luponia, Trivia. Fig. 444 to 450.

2. OVULUM. Lips thickened, inflected, with slight crenulations; spire hidden. Fig. 440 to 443.

3. ERATO. Lips thickened, inflected; spire visible; a groove down the back. Fig. 454.

4. TEREBELLUM. Cylindrical, open at the anterior extremity; columella smooth; suture of the spire canaliculated. Fig. 451, 452.

5. OLIVA. Columella plaited, swelled into a varix at the anterior. Fig. 457, 458.

6. ANCILLARIA. The same, but the suture of the spire covered with enamel. Fig. 455, 456.

7. CONUS. Turbinated, numerous whorls; spire flat or short, conical; columella smooth. Fig 459 to 462.

CONVOLUTE. (Con, together; volvo, to revolve). This term can be strictly applied only to symmetrical shells, signifying that the volutions are parallel to each other in a horizontal direction, as in the Ammonites, &c.; but the term is also commonly used in describing such shells as Conus, in which, the direction of the whorls being scarcely oblique, the last whorl almost entirely covers those which precede it. This is the case with Lamarck's family of Enroulées. Fig. 440 to 462.

CORALLIOPHAGA. Bl. CYPRICARDIA Coralliophaga, Lam.--Descr. Oval, elongated, finely striated from the apex to the base, cylindrical, equivalve, very inequilateral; umbones slightly raised and quite anterior; hinge nearly the same in both valves; two small cardinal teeth, one of which is bifid, placed before a kind of lammellated tooth, beneath a very slender external ligament; two small, distant, muscular impressions, united by a striated palleal impression, which is strongly striated posteriorly.--Obs. This shell, which is found in the empty holes of dead Lithodomi, in some instances conforming its shape to its situation, differs from Cypricardia of Lamarck, principally in its cylindrical form. C. Carditoidea, fig. 92. Mediterranean and East Indies.

CORBICULA. Megerle. CYRENA, Lam.

CORBIS. Cuv. (A basket.) Fam. Nymphacea, Lam.--Descr. Transverse, oval, thick, ventricose, equivalve, sub-equilateral, free, cancellated, with denticulated internal margins; hinge with two cardinal and two lateral teeth in each valve; of the latter, one near and one remote from the umbones; muscular impressions lunulate, two in each valve, united by an entire palleal impression, without a sinus.--Obs. This genus, of which only two or three recent species are known, resembles many species of Venus and Cytherea in general form; but differs in having lateral teeth, and in the palleal impressions which in all the Veneres, &c. is sinuated. From Lucina it may be known, not only by its oval form, but also by the muscular impressions, which, in Lucina are produced into an elongated point; it will also be distinguished from Tellina, by the want of a posterior fold in the valve, for which that genus is remarkable. C. Fimbriata, fig. 101, is an inhabitant of the Indian Ocean. Several fossil species are found in the recent formations, above the chalk, at Grignon and Hauteville.

CORBULA. Brug. (A little basket.) Fam. Corbulacea, Lam. Conchacea, Bl.--Descr. Inequivalve, sub-equilateral, transverse, gibbose, not gaping; cardinal tooth in each valve, conical, curved, prominent, inserting its extremity into a pit in the opposite hinge; cartilage attached to the tooth of the smaller valve, and the pit in the larger; muscular impressions, two in each valve, distant, rather irregular; palleal impression posteriorly angulated.--Obs. The shells composing this genus were placed in Mya by Linnæus, but differ from the true Myæ in having a sinus in the palleal impression, and a prominent ligamentiferous tooth in each valve, whereas the Myæ have but one. The Corbulæ are marine, some species inhabiting the British coasts. Fossil species occur abundantly in green sand, London clay, crag, and corresponding formations. Fig. 89. C. Nucleus.

CORBULACEA. (Corbulées, Lam.) A family of the order Conchifera Dimyaria, Lam., containing the genera--

1. CORBULA, with a prominent curved tooth. The Fresh-water species has been separated under the name Potamomya. Fig. 89.

2. PANDORA. Thin, pearly, no teeth. Fig. 90.

CORDIFORM. (Cor, a heart.) Heart-shaped, a term applied generally to any shell which may be fancied to resemble a heart in shape, as Isocardia, fig. 126, and Cardium Dionæum, fig. 122.

CORIACEOUS. (Corium, leather.) Of the substance of leather. Ex., the integument into which the valves of Chitones are inserted.

CORIOCELLA. Bl. The animal designated by this name is described by De Blainville as being without any traces of shell, either internal or external. This must have arisen from the imperfection of the specimen described, probably deprived by accident of its shell. The testaceous appendage of the Coriocella is now well known to naturalists. It is a milky white, transparent shell, shaped like Sigaretus.

CORNEA, and PISUM, Megerle. CYCLAS, Lam.

CORNEO-CALCAREOUS. A term used to express the mixture of horny and shelly matter which enters into the composition of some shells, Aplysia, for instance. It is also applied to those Opercula, which are horny on one side, and testaceous on the other, as that of Turbo.

CORNEUS. Horny. A species of Patella has had the specific name corneus given to it, because its texture more nearly resembles that of a horn than that of a shell. The epidermis of fresh-water shells is of a similar composition.

CORNUCOPIA. Humph. LEPAS, Linn.

CORONALES. See CORONULAR MULTIVALVES.

CORONATED. (Corona, a crown.) Applied to shells when ornamented with a series of points, tubercles, &c., round the upper edges of the volutions. Ex. Conus Nocturnus, fig. 459.

CORONAXIS. One of the two genera into which Swainson divides the genus Conus, consisting of those species which have a row of tubercles on the upper edge of the whorls, an arrangement by which he would in many instances, not only separate between two individuals of the same species, but also between two parts of the same shell; for instances occur in which the earlier whorls are coronated, while the body whorl and the penultimate are perfectly plain.