This is a very common species washed ashore and living on and under calcareous rocks to depths of more than 60 metres. Lindberg & Vermeij (1985) were the first to refer this species to the Patelloida profunda group, "a Tethyan clade that appears to be specialised for life on calcareous substrata".
The shell has a low to medium high profile, with a conspicuous sculpture of weak radial ribs and concentric growth lines. Its colour is always dull white, often with pale reddish markings, usually as radiating rows of small dots or solid bands.

Patelloida pustulata (Helbling, 1779) Spotted Limpet
Distribution: Florida, Texas; West Indies; Bermuda. Size: 13 to 25 mm.
Description: Color chalk white, sometimes flecked with red spots and bars, interior glossy white; shell sculpture thick with thick axial ribs crossed by concentric threads giving a knobby appearance; shell relatively short, no fissure present; apex somewhat pointed and closed.
Habitat: Attached to hard surfaces. In Texas found at the FGB. Depth range 0 to 60 m (197 ft).
Remarks: A smaller form lives on turtle grass, has a narrow shell, and is rose-colored or opaque white with brown rays on either side and sometimes flecked with red (forma pulcherrima Petit, 1856). See Warmke and Abbott (1961); Lipka (1974). Synonym: Acmaea pustulata (Helbling, 1779).