BIVALVIA. 199 
Cyprina TRIANGULARIS. Twrt. Brit. Biv., p. 136, pl. ui, figs. 19, 20, 1822. 
CYTHEREA MINIMA. Brown. Brit. Conch. Illust., pl. xix, fig. 3, 1827. 
— MINUTA. Id. 5 53 pl. xix, fig. 4, 1827. 
— TRIANGULARIS. Macgil. Moll. Aberd., p. 268, 1843. 
— TRigoNa. Nyst. Coq. Foss. de Belg., p. 172, pl. xu, fig. 4, 1844. 
_ aprcatis. Phil. En. Moll. Sic., vol. i, p. 40, pl. iv, fig. 5, 1536. 
— — Forbes. Mgean Invert. Rep. Brit. Assoc., p. 182, 1843. 
— cyRILuI. Phil. En. Moll. Sic., vol. ii, p. 32, 1844. 
—_ PUSILLA. Bonelli fide Sismonda. 
— LENTICULA. S. Wood. Catalogue, 1840. 
Exouera orpicutata’? suv. Brown. Brit. Conch. Mlust., pl. xx, figs. 19, 20, 1827. 
CiRcE TRIANGULARIS. King. Ann. Nat. Hist., vol. xv, p. 112. 
— minima. Forb. and Hani. Hist. Brit. Moll., vol. i, p. 446, pl. xxvi, figs. 4, 5, 6, 8> 
and Animal, Pl. m, fig. 3, 1848. 
CRASSINA MINIMA. Gray. Aun. of Philos., 1825. 
Spec. Char. Testd parvd, ovato-rotundatd vel subtrigond, subequilaterali, compressa, 
transversim striata, striis levibus, convewis ; lunuld distinctd ; margine iategerrimo. 
Shell small, roundedly ovate, or of a subtrigonal form, nearly equilateral, com- 
pressed, transversely striated, strie rounded and smooth; lunule distinct; margin 
smooth. 
Diameter, ths of an inch. 
Localities. Cor. Crag, Sutton. 
Red Crag, Sutton. 
Recent, Augean, Mediterranean, Britain, Zetland. 
This species, in the Coralline Crag, is very abundant; my cabinet contains only two 
individuals from the Red Crag. In outward form it presents considerable variation, 
some specimens having a longitudinal diameter much greater than its height, while in 
others the height exceeds the length; the prominence in the umbo of some individuals 
gives rather an angularity to the upper part of the shell, but there is no distinct 
triangular variety. 
CoraALLiopHaGa.* De Blainv., 1824. 
cypricarpia (sp.) Lamarck. 
VENERUPIS (sp.) Basterot. 
Gen. Char. Shell transversely ovate or oblong, equivalved, inequilateral, closed ; 
rugged or smooth externally; hinge furnished with two teeth in each valve, or two 
diverging in one valve, with one triangular and interlocking in the other. Two ovate 
muscular impressions ; mantle mark with small indented sinus. Ligament external. 
* Etym. copaA\or, coral, and gayw, to eat. 
