What is "valvata"

Valvata \Val*va"ta\, n. [NL.; cf. L. valvatus having folding doors. See Valve.] (Zo["o]l.) A genus of small spiral fresh-water gastropods having an operculum.

Valvata is a genus of very small freshwater snails with an operculum, aquatic gastropod mollusks in the family Valvatidae, the valve snails.