A. villosa.

A. dentata.

A. striata.

A. vitrea.

A. lævis. The smooth Anatifera. Pl. [4], fig. 5.

Five smooth valves; the dorsal one rounded at the sides, and slightly carinated; peduncle long, naked, of a scarlet colour.

8. Pollicipes. Three species.

Easily distinguished by the numerous small valves situated at the base.

Pollicipes cornucopia.

P. mitella.