C. nucleus. The kernel Corbula.

Strong, sub-triangular, under valve larger than the upper one; transversely striated; covered with a thick brownish epidermis.

C. ovalina. The ovate Corbula. Pl. [6], fig. 6.

Regular species.

C. Australis. The Australian Corbula.

Irregular species, living in stone.

2. Pandora. Two species.

Closely allied to the Corbula.

Pandora rostrata.

Pandora obtusa.