Shell coarsely sculptured, with strong, angular ribs, bearing small scales or spines and pro-jecting strongly at the margin. Shape varies somewhat according to habitat. Exterior white or pale brown; interior white, sometimes with a brownish centre. Maximum length 100 mm.

Powell:
Shell rather large, up to 95 mm. (3,75 inches) in length, of only moderate height and weight in its younger stages but tall and crass in mature examples, narrowly to broadly ovate, with the apex near central. Sculpture variable, but always strongly and coarsely radially ribbed, their terminal points corrugating the margin, sometimes almost as strongly as in longicosta. Radial ribs carinated and of varying strength, from 10 to 20 primaries and 1 to 4 secondaries in the interspaces, the whole rendered noticeably scabrous by close set, lamellose, concentric growth marks. The posterior end of the shell usually has 5 ribs much stronger than the rest. Colour: externally dull-buff to light yellowish brown; internally whitish, often with a narrow, pale-fawn, marginal border; spatula either irregularly blotched with reddish-brown, or callused over with white. A variable species, as shown by the lengthy synonymy. Radula: Formula 3 + 1 + (2+1+2) + 1 + 3, similar to that of both longicosta and cochlear in the form of the massive lateral, which has an expanded head, bearing three cusps, the middle one much the larger, and there is an incipient fourth cusp on the outer side. The five centrals have the middle member small and slender, with a minute vestigial cusp, but the cusps of the outer pairs of centrals, and the middle member of the laterals have broad flat tops, with ridged margins; marginals 3, slender, flexuous, and each with a weak cusp. Length: 72-95 mm; Width: 58-70 mm; Height: 22 – 38 mm.

Inhabits Lithothammon-coated rocks at about low spring-tide level, and in pools and submerged situations down to about 6 m. It forms a weak home-scar, which it vacates to feed at random on any minute encrusting organisms. Juveniles often live temporarily on the shells of other gastropods, and a dwarf form with very convex shell and arched base lives on the solitary ascidian Pyura ('Redbait'). Spawns early in winter.

This is a large, solid, ovate limpet, varying greatly in height, but always strongly radially ridged, resulting in a deeply corrugated margin. The coloration is buff to pale brownish externally and white within, except for the spatula, which is often blotched with reddish brown.
Can be confused with P. pica and P. tabularis, but the presence of a black-spotted foot always characterises it. The occurrence of small scales or spines and the absence of a pinkish external colour and margin further distinguish it from tabularis while the white exterior surface and the nature of the ribbing separates it from pica. The shell is almost invariably covered with algae.

Namibia to Zululand. South Africa, the whole length of the coastline from Fort Nolloth in the west to Umpangazi in the east.