EN
Thinobius flagellatus LOHSE, 1984 (Coleoptera: Staphylinidae), a staphylinid beetle new to the Polish fauna, was found (24 specimens) on a sandy bank of the river Bug on 17 V 2001. Locality: Kamieńczyk near Wyszków (Mazovian Lowland, Central Poland). Figures of penis and spermatheca of T. flagellatus are presented.