The shell is coiled dextrally (i.e. clockwise). The thin, double-walled keel of the shell extends outward from the last shell whorl. The apex of the shell is found on the right side, the umbilicus on the left side. The shell and keel can be calcareous (genus "Atlanta"), or composed exclusively of conchiolin (genus Oxygyrus), or the shell can be calcareous and its keel composed of conchiolin (genus "Protatlanta"). The snails of this family can retract into their shell and close it off with a cartilaginous, flexible operculum.