EN
Spinturnix helvetiae DEUNFF, KELLER, AELLEN, 1986 (Acari: Mesostigmata: Spinturnicidae) is ascertained in the Polish fauna for the first time. The checklist of Spinturnicidae mites observed on bats of Poland is supplemented with the newly discovered species and it contains now 8 species of mites (including one with two subspecies). A number of new morphological features differentiating Spinturnix helvetiae infesting Nyctalus leisleri from closely related Spinturnix acuminatus (KOCH, 1836) infesting Nyctalus noctula are described.