Shell thick, solid, oblong-ovate, medium-sized and relatively compressed; elliptical- ovate in outline, distinctly longer than high with thick umbones towards the anterior part, low and rounded. Escutcheon very long and narrow. Outer sculpture rather coarse, with strong, nodulous radial riblets. Radial ribs of the posterior slope strongly diverging and somewhat recurved in the dorsal direction, with moderately wide interstices. Strong hinge plate with 3 cardinal teeth at each valve; anterolateral teeth well developed. Narrow heart- shaped lunule. Inner margin crenulated. Colour: exterior off-white to buff, generally with brown blotches or spots upon the radial ribs. Internally porcelaneous-white with purplish-brown blotches in umbonal, ligament stained with violet.