Thiele, 1931
External shell rather frail, able to accommodate the animal during defensive retraction; several whorls; operculum usually absent.
Cephalic shield bearing rounded or pointed postero-lateral tentacular processes, often concealing the front of the shell. Without conspicuous external posterior pallial lobe. Gizzard plates present (Retusa ) or absent (Rhizorus ). Radula absent.
Source: Thompson, 1988.
The following subtaxa of this family occur in the region:
Genus Retusa
Genus Volvulella
Retusa obtusa
Retusa truncatula
Retusa umbilicata
Volvulella acuminata