CYPRINA. 441 



The Cyprinfc live in gravelly sand or mud, and are not 

 remarkable for beauty, though often of considerable size. 

 They are chiefly found in moderately deep water. An- 

 ciently they were much more abundant than now, and 

 within our own area several well marked species lived at 

 the commencement of the cretaceous epoch, apparently 

 having similar habits with their existing congeners. The 

 absence of the pallial sinus in the casts serves readily to 

 distinguish between fossil species of Cyprina and Venus 

 otherwise very nearly alike. 



C. IsLANDicA, Linnseus. 



Plate XXIX, and (animal) Plate M. Fig. 4. 



Venus Islandica, Linn. Syst. Nat. ed. 12, p. 1131 (not of 0. Fabr. Fauna Groen- 

 landica, p. 411). — Pulteney, Hutchins, Dorset p. 33. — 

 DoNov. Brit. Shells, vol. iii. pi. 77. — Mont. Test. Brit. p. 

 114. — Linn. Trans, vol. viii. p. 83. — Dorset Catalog, p. 3.5, 

 pi. 6, f. 5. — TuRT. Conch. Diction, p. 238. — Chemn. Conch. 

 Cab. vol. vi. p. 340, pi. 32, f. 341, 342. — Muller, Zool. 

 Dan. pi. 28. — Dillvv. Recent Shells, vol. i. p. 176.— Index 

 Testaceolog. pi. 7, f. 41. 

 Venus mercenaria, (not of Linn.) Penn. Brit. Zool. ed. 4, vol. iv. p. 94, pi. 53, 



f. 47. 

 Pectunculus crassus, Da Costa, Brit. Conch, p. 183, pi. 14, f. 5. 

 C'yprina hlandica. Lam. Anira. s. Vert. (ed. Desh.) vol. vi. p. 290. — Turt. 

 Dithyra Brit. p. 135. — Flem. Brit. Anim. p. 443. — 

 Macgilliv. Moll. Aberd. p. 257. — Brit. Marine Conch, 

 p. 81. — Crouch, Introd. Conch, pi. 7, f. 2. — Blainv. 

 Man. Malacol. pi. 70, bis, f. 5. — Deshayes, Elem. Conch, 

 pi. 18, f. 8, 9, 10.— Gould, Invert. Massach. p. 82. — 

 Hanl. Recent Shells, vol. i. p. 95. 

 Cyprina ruhjaris, Sowerby, Genera Shells. — Brown, 111. Conch. G. B. p. 93, 

 pi. 37, f. 1, and pi. 38, f. 11.— Sow. Conch. Manual, f. 

 116. — Reeve, Conchol. Systemat. pi. 65. 

 Ci/princ d' Islande, Chenu, Traite Elem. p. 68, f. 243 (hingo). 



The general form is suborbicular and somewhat heart- 

 shaped; the valves are solid, often ponderous, moderately 

 inequilatei'al, and ventricose ; the convexity being chiefl}' 



VOL. I. 3 L 



