Marine bivalve mollusc up to 90 mm, generally smaller, of thin and fragile shell; valves are different, since the left valve is more convex than the right valve. The dorsal part is equilateral, and in this part has more or less equal wings. The anterior one of the right valve is slightly bigger than the posterior one, and overlaps that existing in the left valve. Has a clear fold along the line of the hinge under which appears an area until the finely toothed lunula at the edge. The ventral part is semicircular. The sculpture is formed by 20 radial ribs and concentric lines, with the phases of growth not well known. The margin is very crenulate. Variable color, from light pink to brown, orange or yellowish, usually with bands, zigzags, stripes and speckles lighter or darker. The right valve is usually paler than the left.