See text Bithynia is a genus of small freshwater snails with an operculum, aquatic prosobranch gastropod mollusks in the family Bithyniidae.

[2] The diploid chromosome number of Bithynia sp.

[4] Glöer (2002)[5] recognized four subgenera Bithynia, Codiella, Neumayria and Parafossarulus within European species.

He reassigned two European extinct species of Parafossarulus into a subgenus of the genus Bithynia, but the genus Parafossarulus is generally accepted for the Asian species.

[5] The subgenus Digoniostoma is also recognized for Asian species.