What is "amnicolidae"

Amnicolidae is a family of small freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the superfamily Rissooidea.

This family is in the clade Littorinimorpha (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). This family was previously considered to be a subfamily of Hydrobiidae.