Length 52 mm, height 33 mm, breadth 30 mm. Shell thick, solid, elongated quadrate in outline. Beaks more anterior than the central. Hinge line straight. Antero-ventral margin sharply sloping. Ventral margin barely convex, continuous to roundish posterior margin. Surface white, with 28-30 weakly granulated radial ribs. Ligamental area broad with numerous chevron striations. Interior grayish white. Caridnal taxodont, teeth become bigger anteriorly and posteriorly. Ventral margin crenulated. Both valves tightly closed.
Distribution:
Taxas, Louisiana, Misissippi to Brazil via Suriname. Shelf to slope.
Remarks:
The posteriorly sloping antero-ventral corner is very characteristic.