Shell oblong, equivalve, inequilateral with the summits in subcentral-anterior position; valves slightly gaping at least posteriorly; main sculpture concentric; ligament external; hinge with two small cardinal teeth on the left valve; no laterals. Pallial sinus large.
 

« Shell oblong or almost orbicular, slightly gaping, folded in front. Hinge: in the left valve two cardinal teeth that are very little divergent; the anterior deeply divided; the posterior simple and little compressed. In the right valve, a sub-lobed cardinal tooth, more thinned at the base; on each side a fossa with callous edge. » – C. F. Schumacher: Essai d’un nouveau système des habitations des vers testacés, Copenghagen 1817, p.44.