The shell is medium to large in size, longer than wide, thick, elongate, and more or less flat. The shell is inequivalve, meaning that the two valves are not the same size. The outer surface of the shell has coarse and widely spaced concentric lamellae, which are ridges that go around the shell in a circle. The interior of the shell is smooth, with a large muscle scar near the center. The hinge teeth are absent, meaning that there are no teeth on the hinge that allow the two valves to lock together. The margins of the shell are smooth. The color of the shell is white, cream, or pale brown on the outside, and white on the inside