Hydrobiidae, commonly known as mud snails, is a large cosmopolitan family of very small freshwater and brackish water snails with an operculum; they are in the order Littorinimorpha.
Bithynia is a genus of small freshwater snails with an operculum, aquatic prosobranch gastropod mollusks in the family Bithyniidae.
Bythinella is a genus of very small freshwater snails, an aquatic gastropod mollusk in the family Bythinellidae.
Platyla is a genus of very small land snails with an operculum, terrestrial gastropod mollusks or micromollusks in the family Aciculidae.
Pseudamnicola is a genus of small brackish water snails with an operculum, aquatic gastropod mollusks in the subfamily Pseudamnicolinae of the family Hydrobiidae.
Mercuria is a genus of small brackish water snails or freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the family Hydrobiidae.
Acicula is a genus of very small land snails with an operculum, terrestrial gastropod mollusks in the family Aciculidae.
Horatia is a genus of gastropod molluscs, comprising a small group of minute stygobiont freshwater snails with valvatoid shells, belonging to the subfamily Horatiinae of the family Hydrobiidae.
