Shell is solid, laterally compressed, and sub-rectangular in shape. Body surface is decussate, which means it is marked with a network of ridges and grooves. Periostracum is fibrous, hinge is minutely curved and short.
The teeth are horizontally arranged, meaning they are arranged in a row along the hinge.
The outer surface is dark brown, often with 2 or 3 pale bands radiating from the umbones.