Shell small, thin-walled, whitish, often lengthened, with an aperture constricted posteriorly, expanded anteriorly. « At present time gizzard plates morphology only may be used for separating genera. » – E. M. Chaban: “Some materials for revision of opisthobranchs of the family Retusidae (Mollusca: Cephalaspidea)”, Annual Reports of the Zoological Institute RAS, Moscow 2000.
 

Shell often pear-shaped, with 3 small corneous gizzard plates, almost « triangular in shape, slightly curved, light brown coloured with darker tubercles… » – Tringalli & Oliverio: “The recent Mediterranean species of the genus Pyrunculus Pilsbry 1895 (Opisthobranchia; Cephalaspidea, Retusidae)”, Bollettino Malacologico vol.37, Milano 2001, p.153.   Two tubercles per plate.
 

Shell cylindrical or subcylindrical, with a spire very low, sometimes sunken. Gizzard plates corneous, lobate, 3 in number; many tubercles, smaller than in Pyrunculus, on each plate.