Rissooidea, originally named Rissoacea by Gray, 1847, is a taxonomic superfamily of small and minute marine snails, belonging to the clade Littorinimorpha.
Ancylus is a genus of very small, freshwater, air-breathing limpets. They are aquatic pulmonate gastropod mollusks in the tribe Ancylini within the family Planorbidae, the ram's horn snails and their allies.
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.
Helicidae is a large, diverse family of small to large, air-breathing land snails, sometimes called the "typical snails."
Bithynia is a genus of small freshwater snails with an operculum, aquatic prosobranch gastropod mollusks in the family Bithyniidae.
Viviparus, common name the river snails, is a genus of large, freshwater snails with an operculum, aquatic gastropod mollusks.
Gyraulus is a genus of small, mostly air-breathing, freshwater snails, aquatic pulmonate gastropod mollusks in the family Planorbidae, the ram's horn snails.
Radix is a genus of air-breathing freshwater snails, aquatic pulmonate gastropods in the family Lymnaeidae, the pond snails.
Ferrissia is a genus of small, air-breathing freshwater limpets, aquatic gastropod mollusks in the family Planorbidae, the ram's horn snails and their allies.
Hydrobia is a genus of very small brackish water snails with a gill and an operculum, aquatic gastropod mollusks in the family Hydrobiidae.
Melanopsis is a genus of freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the family Melanopsidae.
Pseudamnicola is a genus of small brackish water snails with an operculum, aquatic gastropod mollusks in the subfamily Pseudamnicolinae of the family Hydrobiidae.
Theodoxus is a genus of nerites, small water snails with an operculum, some of which live in freshwater, and some in both freshwater and brackish water, aquatic gastropod mollusks in the family Neritidae, the nerites.
Valvata is a genus of very small freshwater snails with an operculum, aquatic gastropod mollusks in the family Valvatidae, the valve snails.
Melanopsidae, common name melanopsids, is a family of freshwater gastropods in the clade Sorbeoconcha. Species in this family are native to southern and eastern Europe, northern Africa, parts of the Middle East, New Zealand, and freshwater streams of some large South Pacific islands.
Tanousia is an extinct genus of freshwater snails with gills and an operculum, a gastropod mollusk in the family Lithoglyphidae.
Pyrgula is a genus of freshwater snail with a gill and an operculum, an aquatic gastropod mollusk in the family Hydrobiidae.
Lithoglyphus is a genus of freshwater snails with gills and an operculum, a gastropod mollusk in the family Lithoglyphidae.
Potomida is a genus of bivalves belonging to the subfamily Gonideinae of the family Unionidae.
Congeria is a genus of bivalves belonging to the family Dreissenidae.
