The species has a shell that is swollen and not perfectly symmetrical. It has many closely spaced, bumpy, and ribbed lines that radiate out from its center. The ribs in the front part of the shell are somewhat flattened and point backward, while the ones in the middle are notched. The ribs in the back are spiky. The grooves between the ribs are narrower than the ribs themselves, and there are fine lines on the surface indicating growth. Inside the shell, it is ribbed, except when it’s young. There are two small cardinal teeth per valve, and strong, plate-like lateral teeth. The opening at the back of the shell is very narrow or may not be fully developed.