Solid, oval, triangular shell. Symmetrical valves, with serrated concentric ribs, some wider than others. Hinge with three cardinal teeth on each valve. Pallial sinus short and pointed. Valve edge finely toothed. Whitish, greyish or brown coloration, decorated with zigzag patterns and lighter radial bands; whitish interior, with purplish spots. Up to 3 cm in length.