helicinidæ

from The Century Dictionary.

• A family of rhipidoglossate gastropods of the order Streptoneura, having the epipodium without tentacles, branchia absent, mantle-cavity transformed into a pulmonary chamber, heart with a single auricle, not traversed by the rectum, and the operculum without apophysis. It contains the genera Helicina, Hydrocena, and Georissa, all terrestrial and found in warm regions.