This genus approximates the Crassatella and Ungulina, but is
distinguished from them by the inequality of the valves and the strong
primary tooth.
Shell rather solid, a little irregular and triangular, inequivalve, more
or less inequilateral, rounded and enlarged before, attenuated and
prolonged behind; summits well marked, one projecting behind the other;
hinge anomalous, formed by a large, conical, recurved cardinal tooth,
with a cavity at its base for the reception of the tooth of the other
valve; ligament very small; two muscular impressions little distant.
Corbula Australis.
C. sulcata.
C. erythrodon.
C. ovalina.
C. Taitensis.
C. nucleus.
C. impressa.
C. porcina.
C. semen.
_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.