9. Genus Capsa. Pl. [VII].
Animal. As above.
Shell. Transverse, equivalve, valves approximate and close; three primary teeth in the right valve, and a single bifid tooth in the left, inserted into a cavity in the opposite one; no lateral teeth; ligament external and on the short side, as in Donax, from which it was separated by Lamarck, on account of the peculiarity of the hinge, inhabits the Indian Ocean. Three species.
- Capsa levigata.
- C. Braziliensis.
- C. Donaoides.
10. Genus Crassina. Pl. [VII].
Animal. As above.
Shell. Distinguished from the Venus by having only two teeth on each valve, and from the crasatella by the position of the ligament; solid, suborbicular, thick, hinge with two strong diverging primary teeth in the right valve, and two unequal ones on the other; ligament external. Inhabits the Scottish and Devonshire coasts. One species.
- Crassina Danmoniensis.
FAMILY IX.
Conchacea. Seven Genera.
This family is divided into Conchæ Marinæ, and Conchæ Fluviatiles.