Conical smooth shell to 30 mm; whorls & base more rounded than C. montereyi but not as rounded as C. brunnea. Inner edge of aperture a flange that separates it from open umbilicus (arrow); base of shell & inner lip of aperture smooth, lacking ridge, notch or tooth (inset). Side of foot black with faint pale lines & pale margin.
Very abundant, on rocks, low-lying algae, & giant kelp. Herbivorous.
Geo Range: Sitka Alaska to Baja
Synonyms: Tegula pulligo
Similar species: Chlorostoma brunnea is more round, lacks open umbilicus; Chlorostoma montereyi has fine spiral striations on shell & edge of open umbilicus spirals upward toward apex.
Image: Garnotia adunca (on shell).