30mm. Thick, dull, globose with slightly raised spire, protoconch always eroded. Columella has 4 strong teeth; callus pad is irregularly granulated; outer lip has close-set ridges inside and 2 large teeth at top. Low, spiral ribs and coarse growth lines. Greenish, yellowish brown or blackish, often mottled and dotted; apertural area white with dark rim. callus pad tinged orange. Habitat: intertidal on rocks.