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.