Ohridohauffenia drimica was a species of very small freshwater snail with an operculum, an aquatic gastropod mollusk in the family Hydrobiidae, the river snails. This species is now extinct.
Austropyrgus dyerianus is a species of minute freshwater snail with an operculum, an aquatic gastropod mollusk or micromollusk in the Hydrobiidae family. This species is endemic to Australia.
Beddomeia bowryensis is a species of gastropod in the family Hydrobiidae. It is a species of very small freshwater snail that has a gill and an operculum, an aquatic operculate gastropod mollusk in the family Hydrobiidae. This species is endemic to Australia.
Miller's snail, scientific name Cochliopina milleri, is a species of very small freshwater snails that have an operculum, aquatic gastropod mollusks in the family Hydrobiidae, the mud snails. This species is endemic to Mexico.
Marstonia agarhecta, common name Ocmulgee marstonia, is a species of freshwater snail with a gill and an operculum, aquatic gastropod mollusk in the family Hydrobiidae.
Marstonia ogmorhaphe, common names the royal marstonia or royal springsnail, is a minute species of freshwater snail, an aquatic gastropod mollusk or micromollusk in the family Hydrobiidae, the mud snails. This species is endemic to Tennessee in the United States, where it occurs in two streams in Marion County. It is a federally listed endangered species of the United States.
Marstonia olivacea, common name the olive marstonia, was a species of very small freshwater snail, an aquatic gastropod mollusk in the family Hydrobiidae. This species was endemic to Alabama, the United States. Its natural habitat was rivers. This species is now extinct.
Marstonia ozarkensis, common name the Ozark pyrg, was a species of very small or minute freshwater snails with an operculum, aquatic gastropod mollusks in the family Hydrobiidae. This species was endemic to the United States and was presumed extinct by the U.S. Fish and Wildlife Service as of December 2018.
The armored marstonia, scientific name Marstonia pachyta, also known as Pyrgulopsis pachyta, is a species of freshwater snail, an aquatic gastropod mollusk in the family Hydrobiidae.
The reverse pebblesnail, scientific name Somatogyrus alcoviensis, was a species of small freshwater snail with a gill and an operculum, an aquatic gastropod mollusk in the family Hydrobiidae.
The angular pebblesnail, scientific name Somatogyrus biangulatus, is a species of very small freshwater snail with an operculum, an aquatic operculate gastropod mollusk in the Hydrobiidae family. This species is endemic to the United States. Its natural habitat is rivers. This snail is only located in specific freshwater cave environments and has not been extensively studied.
The thick-lipped pebblesnail, scientific name Somatogyrus crassilabris, was a species of freshwater snail with an operculum, an aquatic gastropod mollusk in the family Hydrobiidae, the mud snails. This species was endemic to the United States. Its natural habitat was rivers. It is now extinct.
The Tennessee pebblesnail is a species of very small freshwater snail with an operculum. It is an aquatic gastropod mollusk in the family Hydrobiidae.
The Tallapoosa pebblesnail, scientific name Somatogyrus pilsbryanus, is a species of very small freshwater snail with an operculum, an aquatic gastropod mollusk in the family Hydrobiidae. This species is endemic to the United States. Its natural habitat is rivers. The common name of this pebblesnail refers to the Tallapoosa River, which runs through the states of Georgia and Alabama.
The quadrate pebblesnail, scientific name Somatogyrus quadratus, is a species of small freshwater snail with a gill and an operculum, an aquatic gastropod mollusk in the family Hydrobiidae. This species is endemic to the United States. Its natural habitat is rivers. This species is possibly extinct because there is no recent survey information. It is known to have had a very restricted distribution and there had been a habitat disturbance. This species was endemic to the Tennessee River system and was known to exist from Muscle Shoals and adjacent Shoal Creek, Lauderdale County, Alabama. It has not been reported since the river was impounded. Based on the fact that the species has not been observed since the dams were constructed, it is widely believed that that change in habitat possibly caused the species's extinction.
The Panhandle pebblesnail, scientific name Somatogyrus virginicus, is a species of very small or minute freshwater snail with an operculum, an aquatic gastropod mollusk in the family Hydrobiidae. This species is endemic to the United States. Its natural habitat is rivers, where it prefers areas with the fastest current.
Brune's tryonia, scientific name Tryonia brunei, is a species of very small freshwater snail that has a gill and an operculum, an aquatic gastropod mollusks in the family Hydrobiidae. This species is endemic to the United States (Texas). It was formerly listed as Threatened in 1993/1994 and Data Deficient since 1996 until it was changed to Critically Endangered and possibly extinct in 2012; this is because it is found only in Phantom Lake, Balmorhea Lake, has range of less than 100 km², and was last observed in 1993. A 1991 report by the United States Fish and Wildlife Service also listed it as Endangered and they also later noted the unknown population. It is found in firm substratum and on mud before modification.
Marstonia scalariformis, previously known as Pyrgulopsis scalariformis, common name the moss pyrg, is a species of freshwater snail with a gill and an operculum, aquatic gastropod mollusk in the family Hydrobiidae.
Marstonia is a genus of freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the family Hydrobiidae.
Floridobia is a genus of very small freshwater snails that have an operculum, aquatic gastropod molluscs or micromolluscs in the family Hydrobiidae, the mud snails.
