Shell: thin, fragile, subquadrate; inequilateral, posterior end much longer; sculpture of irregular, slightly wavy commarginal striae, and fine, dense punctae; ventral margin with sparse, broad, low radial undulations; periostracum thin, light beige, silky; hinge plate narrow; right valve with one short anterior cardinal tooth, one elongate posterior lateral tooth; left valve with two minute anterior cardinal teeth, one elongate posterior lateral tooth. Mantle: large, reflected, covering most of outer shell surface when fully extended, including umbones; two anterior and two posterior tentacles, short, slightly extending past shell margins. Foot: large, translucent, exceeding the length of the shell when fully extended, spathate, with distinct pointed heel. |