Original description, by Conrad (1870, p. 72):
"Hinge Character - Right valve - three diverging cardinal teeth, posterior one bifid; cardinal plate broad, deeply channelled anteriorly, with a compressed lateral tooth in the middle of the channel; plate deeply channeled posteriorly. Left valve with three diverging cardinal teeth, the anterior one v-shaped, oblique ; one distant anterior lateral tooth with a channel above, parallel with the cardinal margin; nympha crenulated on the upper margin; a distant narrow channel on the posterior hinge plate; pallial sinus deep, reaching to a point in a line with the posterior extremity of the posterior cardinal tooth; rounded and somewhat ascending.
This genus is nearly related to the Eocene genus Isodoma, Desh. It differs in having three teeth in the right valve instead of two bifid teeth, and in having no lateral tooth posteriorly on the left valve, but a narrow pit in place of a tooth. It has also a much wider hinge plate and a crenulated nympha. The v-shaped tooth on the left valve is a very peculiar and distinctive character."