« Shell very small, equivalve, closed, oval or suborbicular; hinge with a well marked anterior lateral tooth and one or two cardinal teeth; non-constant posterior lateral tooth; ligament external; palleal line entire. This family contains shells remarkable for the development of the anterior lateral tooth, which is placed below the cardinal tooth. » – P. Fischer: Manuel de Conchyliologie et de Paléontologie Conchyliologique fasc.11, Paris 1887, p.1022.
 

Margins « channeled within; hinge of right valve emarginate under the apex, and having one pyramidal tooth anteriorly; hinge of left valve with a pit under the apex, and two compressed diverging teeth anteriorly… » – T. A. Conrad: “Descriptions of new Eocene shells from Enterprise, Mississippi”, American Journal of Conchology vol. I, Philadelphia 1865, p.138.
 

Shell inequilateral, tumid, thin, whitish, smooth except minute growth-marks. Beaks prosogyrate; anterodorsal margin small, curved; posterodorsal margin wide, rounded; lunule shallow, heart-shaped.