These small to large chitons are characterized by a broad girdle with erect tufts of up to ten large bristles. The coarsely granular valves of the shell are partially overlapped by the girdle. This girdle is all covered by coarse spines. The articulating flange, or articulamentum, is well developed. The margin of the cephalic plate has about five slits. The lateral insertion plates all have a single notch