Key to the European species of Helicopsychidae

1 Dorsal head capsule with more than 17 pairs of primary setae (Figs. 30, 31); propleuron with sharply-angled dorsal outline, its anterior process cuneiform, straight dorsally, and strongly tapering (Fig. 32); submentum broadly triangular, with rounded posterior edge (Fig. 33)................................................................... Helicopsyche bacescui

- Dorsal head capsule with only 17 pairs of primary setae (Figs. 1, 22, 34); propleuron with sharply-angled or rounded dorsal outline; submentum trapezoidal (Figs. 24, 40) or triangular (Figs. 4, 37)...........................................

2 Propleuron in lateral view with sharply-angled dorsal outline (Figs. 27, 39); submentum trapezoidal (Figs. 24, 40)........ 3

- Propleuron in lateral view rounded dorsally (Fig. 9); submentum triangular (Figs. 4, 37)............................ 4

3 Propleural anterior process long, nearly straight, and digitate (Fig. 39); submentum posterior edge nearly straight and only slightly narrower than anterior edge; anterior edge straight (Fig. 40)........................... Helicopsyche lusitanica

- Propleural anterior process short, curved anterad, and apically acute (Fig. 27); submentum posterior edge rounded and much narrower than anterior edge; anterior edge convex (Fig. 24)................................... Helicopsyche revelieri

4 Propleural anterior process straight and tapering only apically (Fig. 36); submentum broadly triangular, with blunt posterior tip (Fig. 37)............................................................................. Helicopsyche sperata

- Propleural anterior process curved anterad and gradually tapering throughout its length (Fig. 9, black arrow); submentum heart-shaped, with pointed posterior tip (Fig. 4)......................................... Helicopsyche megalochari