Shell oval-wedge shaped, rather stout, beaks subterminal. Ventral margin straight to very weakly convex. Postero- dorsal margin markedly convex. Ligament plate slightly arched in anterior part, straighter in posterior part. Exterior smooth, with pronounced irregular growth lines. Periostracum dark brown and rather glossy. Anterior byssus retractor scar on anterior part of the umbonal cavity, in front of the beaks. Anterior part of posterior byssus retractor muscle scar under the posterior third of the ligament, near the end. Animal with large gills. Mantle lobes on anterior half of ventral side separate. Valvular siphonal membrane short.
CAVANAUGH C. M., WIRSEN C.O. & H.W. JANNASCH (1992) Appl. Environ. Microbiol. 58: 3799-3803.