10. A. exoleta, Linn.—(Venus) Cytherea e., Pectunculus capillaceus.—Sandy ground, on Brit. co. generally, low-water to 80 fath., C. Compressed; striæ coarse.
11. A. lincta, Pult.—(Venus) V. sinuata, Cytherea sinuata.—Various Brit, loc., C. Dorsal edge sloping; striæ fine.
Venus.
12. V. casina, Linn.—V. reflexa, V. lactea, V. discina.—Northumberland, S. Devon, Man, Bantry, Skye, etc., Mc. Concentrically laminated.
13. V. verrucosa, Linn.—V. erycina, V. cancellata, etc.—Devon, Cornwall, Channel Isls., etc., C. Ventricose, warted.
14. V. fasciata, Donov.—Various southern Brit, loc., C. Round, with thick ribs.
15. V. ovata, Pennant.—Brit. co. generally, C. Oval, radiately ribbed.
16. V. striata, Donov.—V. gallina, V. Pennantii, V. rugosa.—Brit. co. generally. Shores and deep water, C.
Astarte.
17. A. triangularis, Mont.—Mactra and Goodallia, minutissima and triangularis.—Northern parts of Britain, 15 to 20 fathoms, C. Minute, triangular.