Family Crassatellidae

Shell size to 50 mm; shell heavy, wedge-like, thick, shell is 30% longer than high. Sculpture of 50-60 closely arranged concentric ribs. Posterior ridge present. Hinge large, cardinal teeth forming angle, well-developed. Color orange with bands of lighter color. Periostracum brown.

Shell size to 8 mm; shell small, narrow, triangular, very compressed. Sculpture of at least 15-17, concentric, coarse ribs. Umbo sub-central, displaced toward anterior region. Color whitish or pinkish. Interior of valves mostly brown.