Bythinella vidinovae — a new species (Mollusca: Gastropoda: Bythinellidae) from the Pirin Mountains, south-western Bulgaria

Abstract
A new species of the genus Bythinella, Bythinella vidinovae sp. nov., is described from a tributary of the Sandanska Bistritsa river, Pirin Mountains, south-western Bulgaria. The new species is an interesting case of a rheophilic species known only from the type locality.