Key to the known species of Ceratorchestes
(revised after Ermilov & Kalúz 2012)
1. Epimeres III + IV normal, not remarkable longitudinally elongated (distance between sejugal apodeme and anterior margin of genital aperture shorter than length of genital plate); all or some setae of epimere IV inserted lateral to genital aperture and comparatively close to epimeral border IV.............. 2 ( Ceratorchestes (Paraceratorchestes) Ermilov & Kalúz, 2012).
- Epimeres III + IV remarkable longitudinally elongated (distance between sejugal apodeme and anterior margin of genital aperture longer than length of genital plate); all setae of epimere IV inserted anterior to genital aperture and distinctly removed from epimeral border IV.............................. 4 ( Ceratorchestes (Ceratorchestes) Balogh & Mahunka, 1969).
2. Lamellar cusp with strong outer tooth and small inner tooth; translamella located posterior to lamellar cusps; anterior notogastral margin protruding medially; body length: 448–531................. C. (P.) melzeri Ermilov, 2016 (in Ermilov et al. 2016).
- Lamellar cusp truncate; translamella located between lamellar cusps; anterior notogastral margin broadly rounded medially.. ................................................................................................... 3
3. Rostrum truncate; translamella absent; body length: 500–627.................................................................... C. (P.) globosus Balogh & Mahunka, 1969 (in Balogh & Mahunka 1969b; see also Ermilov et al. 2016).
- Rostrum with deep medial indentation; translamella present; body length: 481–813..................................................................................................... C. (P.) variabilis Ermilov & Kalúz, 2012 .
4. Lamellar cusp truncate................................................................................. 5
- Lamellar cusp with outer tooth........................................................................... 7
5. Rostrum tripartite; translamella present; epimeral seta 3a inserted anteromedial to 4a; body length: 465–555.............................................................................................. C. (C.) truncatus sp. nov.
- Rostrum pointed; translamella absent; epimeral seta 3a inserted posterolateral to 2a ................................. 6
6. Interlamellar seta distinctly longer than lamellar seta; body length: 461–488.............................................................................................. C. (C.) baloghi Mahunka, 1983 (see also Mahunka 1982).
- Interlamellar and lamellar setae similar in length; body length: 358–372................. C. (C.) cornutus Mahunka, 1982 .
7. Epimeral seta 3c short, setiform; leg trochanter IV rounded dorsoanteriorly....................................... 8
- Epimeral seta 3c medium-sized, thickened; leg trochanter IV with small tooth or large triangular process dorsoanteriorly... 9
8. Lamellar cusp oblique medially; translamella absent; epimeral seta 3a inserted anteromedial to 4a; body length: 375–390................................................................................ C. (C.) duocornutus sp. nov.
- Lamellar cusp rounded medially; translamella present; epimeral seta 3a inserted posterolateral to 2a; body length: 390–450................................................................................. C. (C.) tripartitus sp. nov.
9. Leg trochanter IV with large triangular process dorsoanteriorly; rostral parts of tripartite rostrum similar in length; lateral tooth of prodorsum strong; insertion of rostral seta covered by tutorial tooth; body length: 365–415................................................................................ C. (C.) processus Ermilov, 2016 (in Ermilov et al. 2016).
- Leg trochanter IV with small tooth dorsoanteriorly; lateral parts of tripartite rostrum longer than medial part; lateral tooth of prodorsum minute; insertion of rostral seta not covered by tutorial tooth; body length: 328–348.......................................... C. (C.) setosus Balogh & Mahunka, 1969 (in Balogh & Mahunka 1969 a; see also Ermilov et al. 2016).