Key to the Rhinocylapus -group

1. Head distinctly elongated horizontally (Figs. 1, 2 H–R, 3, 16A); labrum often with distinct spines (Figs. 3 B, D, E); antenniferous tubercle distinctly removed from margin of eye (Figs. 3, 16 A–B); labial segment I long, reaching half of forecoxae; hemelytron always deeply and densely punctate (Figs. 1, 2 H–R, 9, 16D); endosoma with several sclerites and sclerotized lobes (Figs. 10 A, 11A, 12A, 13A, 14A, 15B) ............................................................................... 2

- Head declivous, almost vertical (Figs. 5 A, 7A), short as seen from above (Fig. 2 A–G); labrum without any spines; antenniferous tubercle almost contiguous with margin of eye (Fig. 5 A, 7A); labial segment I shorter, barely reaching base of procoxae; hemelytron with deep and dense punctation or with sparsely distributed, shallow punctures (Fig. 2 A–G); endosoma with a single sclerite (Figs. 6 B, 8A–B, F–G) ................................................................................. 3

2. Antennal segment II in males distinctly thickened near base, then distinctly curved (Fig. 2 I, 4B); embolium broad, rounded laterally, covered with sparse punctation (Fig. 2 H–I, 9C, D); sclerotized portion of ductus seminis inside endosoma relatively long (Fig. 10 A) ...................................................................................... Rhinocylapidius Poppius

- Antennal segment II in males bent medially, not thickened near base (Figs. 2 K–M, P, R, 4C–F); embolium narrow, only gently rounded laterally, without any punctures (Figs. 1, 2 J–R, 9A, B); sclerotized portion inside endosoma short (Figs. 11 A, 12A, 13A, 14A, 15B) ...................................................................................... Rhinocylapus Poppius

3. Hemelytron shallowly and sparsely punctate, sometimes rugose, without any punctures (Fig. 2 E–G)......................... .................................................................................................................................................. Mycetocylapus Poppius

- Hemelytron deeply and coarsely punctate (Fig. 2 A–D) ................................................................. Proamblia Bergroth