in natural history, a genus of vermes, belonging to the order of terebrata. The animal is a limax; the shell is univalve and spiral; the opening is much dilated, and ends in a canal which turns to the left. Gmelin enumerates 53 species; of which only one is peculiar to Britain, the pes pelicanus. The spines are ten; the lip is fingered; the point very sharp; the length two inches.