Potamolithus is a genus of small freshwater snails that have an operculum, aquatic gastropod mollusks in the family Tateidae.
Potamolithus was traditionally classified within the Hydrobiidae. However, anatomical study of Potamolithus by Davis & Pons da Silva (1984) showed its relationship with Lithoglyphus, and it is then placed within the family Lithoglyphidae.
The first appearance of the name Potamolithus was in November 1896 as a nomen nudum (a bare name with no description or illustration). The genus was formally defined by Pilsbry in December 1896.
Potamolithus is the only genus of the family Tateidae in South America. Distribution of Potamolithus includes Argentina (22 species, 11 species are endemic to Argentina), Uruguay (17 species) and Brazil. Potamolithus is the largest genus (i.e. the one with the highest species richness) of recent freshwater snails in Argentina and in Uruguay.
Species within the genus Potamolithus include:
Potamolithus agapetus Pilsbry, 1911Potamolithus bushii (Frauenfeld, 1865)Potamolithus callosus Pilsbry, 1925Potamolithus carinifer Pilsbry, 1911Potamolithus catharinae Pilsbry, 1911Potamolithus concordianus Parodiz, 1966Potamolithus conicus (Brot, 1867)Potamolithus dinochilus Pilsbry, 1896Potamolithus doeringi Pilsbry, 1911Potamolithus felipponei Ihering, 1910Potamolithus hidalgoi Pilsbry, 1896 - synonyms: Potamolithus microthauma Pilsbry, 1896; Potamolithus dinochilus Pilsbry, 1896; Potamolithus hatcheri Pilsbry, 1911Potamolithus iheringi Pilsbry, 1896Potamolithus karsticus Simone & Moracchioli, 1994Potamolithus lapidum (d'Orbigny, 1835) - synonyms: Potamolithus lapidum supersulcatus Pilsbry, 1896; Potamolithus paysanduanus Ihering, 1910; Potamolithus lapidum var. elatior Pilsbry, 1911; Potamolithus callosus Pilsbry, 1926Potamolithus microthauma Pilsbry, 1896Potamolithus orbignyi Pilsbry, 1896Potamolithus paranensis Pilsbry, 1911Potamolithus peristomatus (d'Orbigny, 1835)Potamolithus petitianus (d'Orbigny, 1840)Potamolithus petitianus sykesii Pilsbry, 1896 - synonyms: Potamolithus bisinuatus bisinuatus Pilsbry, 1896; Potamolithus bisinuatus obsoletus Pilsbry, 1896; Potamolithus gracilis gracilis Pilsbry, 1896; Potamolithus gracilis viridis Pilsbry, 1896Potamolithus philipianus Pilsbry, 1911Potamolithus quadratus Pilsbry & Ihering, 1911Potamolithus rushii Pilsbry, 1896 - type genusPotamolithus ribeirensis Pilsbry, 1911Potamolithus simplex Pilsbry, 1911Potamolithus tricostatus (Brot, 1867)Potamolithus troglobius Simone & Moracchioli, 1994Potamolithus valchetensis Miquel, 1998Potamolithus species live in streams. Some species are subterranean, living in caves (for example Potamolithus troglobius and Potamolithus karsticus).
