Shell small, inflated dorsally, irregularly triangular; inequivalve, usually right valve more convex, inequilateral. Ears lacking, ventral margins crenulated. Six radial folds distinct on the exterior ventral side. Ligament internal. Two prominent cardinal teeth with long, narrow chondrophore on the hinges. A large muscle scar towards posterior. Colour: outside of shell creamy-white with red blotches; interior glossy white with hazel muscle scar and submetallic hue on the ventral margin.