Shell very large, hard, heavy, solid, from massive, with strong knobs on the spire. Spiral the whorl convex, with fine spiral threads and a row of large, conspicuous knobs on the shoulder. Dorsal side of the body whorl with low spiral ribs and 2 or 3 spiral rows of blunt, rather weak knobs that are stronger on the shoulder. Mid-dorsal tubercle of the shoulder not much developed in female specimens. I Ventral side of the shell extensively glazed. Columella and outer lip of the aperture nearly smooth. Outer lip with a well marked stromboid notch and 6 short laterally expanded spines, hollow digitations.