Bythinella bertrandi Bernasconi, 2000

« Shell cylindroid, very slender, similar to that of B. cebenensis but more turriculate; as a result of which the ratio length/diameter is above 2.5 (while it is below 2.3 in cebenensis and ferussina) […] The spire growths more slowly than in cebenensis, the length of the last whorl of spire being lower than 50% (greater than 50% in cebenensis and ferussina). » – R. Bernasconi: “Révision du genre Bythinella (Moquin-Tandon, 1855) (Gastropoda Prosobranchia Hydrobiidae: Amnicolinae Bythinellini) de la France du Centre-Ouest, du Midi et des Pyrénées”, Documents Malacologiques hors-série 1, p.34. Above: a specimen from type locality. 3,45mm. Altitude ≈ 310m.