This large shell is heavy and inflated its base flat or slightly concave. The margin is an elongate lump each side of upper half of shell. Teeth on outer lip are broad and short; those opposite finer and longer, except for the four lowest ones which are lager and shorter. The color pattern, seen against a white ground color, occurs in two layers: the pattern of the umderlying layer is bluish ray, the upper layer reddish to dark brown. Pattern of both layers comprises crowded and oftenfused spot and blobs. those of the upper layer often surrounded by yellowish orange color.