Recently, while collecting Hirudinea in the Netherlands we came across the species Trocheta bykowskii GEDROYĆ, 1912 (syn. Blanchardia bykowskii GEDROYĆ, 1916). The genus Trocheta was described by DUTROCHET in 1817. The only European species he mentions is Trocheta subviridis, one of the larger leeches, the length of this animal in rest being 80-140 mm.