Shell very large and massive, up to 147.5 mm. (5,75 inches) in length, broadly ovate, moderately elevated, and with the apex anterior to the middle. Sculpture heavy and coarse, consisting of 9, 10 or more heavy, foldlike, radial ribs, and numerous secondary ribs of several sizes, the whole imbricated by dense lamellose growth lines; margin deeply and somewhat irregularly scalloped. Colour: exterior dull reddish or rusty-brown; interior porcellanous-white, with a moderately wide border of reddish brown, being the external colour showing through at the thinner margin; spatula not differentiated by colour. Radula: Formula 3 + 1 + (2+1+2) + 1 + 3. Central teeth consisting of a slender, almost vestigial, middle member, flanked by pairs of large, blunt-cusped teeth; lateral massive, with an expanded head, bearing four cusps, the middle pair the stronger; marginals three, narrow and slender, each with a weak cusp. Length 80-150 mm; Width: 70-120 mm; Height: 20-50 mm.

This is the largest of the South African limpets; it somewhat resembles S. kermadecensis but has much more prominent radial sculpture.

South Africa, from Cape Peninsula eastward to Port St. John's. The species inhabits the sub-littoral fringe, and does not occur in dense communities.