Shell sculptured with strong spiral ribs; shoulders strongly nodulose. Ribs at the shoulder and below usually alternating large and small. Shoulder nodules crossed by two large bifid ribs and a riblet between. Outer lip thickened, strongly toothed within. Columella smooth, with one tooth posteriorly; umbilicus nearly closed by columellar callus. Anterior canal open, short. Rib coloration fawn, intervening grooves brown, interior and columella white. Shell covered by a thin, smooth yellowish-brown periostracum when alive. Operculum oval. Size: Up to 180 mm, commonly 80 mm, in length.
Distribution: Australia and New Zealand. In Australia, from Caloundra, Qld, to Albany, WA, including Tasmania. Habitat: Among rocks and cunjevoi on exposed rocky shores, intertidally and down to 80 m. Common.
This is the most common large gastropod on rocky shores around Sydney. It can readily be found among cunjevoi, which is its main food, at dead low tide level, and is very common as a beach shell. Its reproduction and early life history are described by Anderson (1959).