1 With 4 mesonotal and 6 metanotal sclerites (Fig. 27); pronotum with low central hump covered with spines (Fig. 28, dotted oval)....................................................................... Goera pilosa (Fabricius 1775)
- With 6 mesonotal and 8 metanotal sclerites (Fig. 7); pronotum without central hump or with larger central hump........ 2
2 Dorsal humps are lacking at the pronotum (Fig. 29)..........................................................3
- Pronotum with 1 or 3 dorsal humps (Figs. 6, 30).............................................................5
3 In dorsal view, distal section of each mesepisternum tapering to blunt apex (Figs. 7 m, 25)............................ 4
- In dorsal view, distal section of each mesepisternum parallel-sided and apically rounded (Fig. 31, arrow)............................................................................................ Lithax obscurus (Hagen 1859)
4 Without posterior face setae at the proximal half of the fore femur (Fig. 32); pronotal muscle attachment spots bordered by black dots (Fig. 33)............................................................. Silo nigricornis (Pictet 1834)
- With posterior face setae at the proximal half of the fore femur (Fig. 34); pronotal muscle attachment spots not bordered by black dots (Fig. 35)................................................................ Silo piceus (Brauer 1857)
5 Pronotum with one central hump only (Figs. 6, 22)...........................................................7
- Pronotum with one central and two lateral humps (Figs. 30, 36)................................................ 6
6 Pronotum with one large central hump reaching the posterior pronotal margin (Fig. 30a) and two smaller lateral humps (Fig. 30b)............................................................................ Silo graellsii Pictet 1865
- Pronotum with three small pale-colored dorsal humps of equal size, central hump never reaching posterior pronotal margin (Fig. 36)..................................................................... Silo pallipes (Fabricius 1781)
7 Pronotal hump noselike (Fig. 6 n), descending stepwise to pronotal surface distinctly anterior of posterior pronotal border (Fig. 6, arrow)................................................................... Silo chrisiammos Malicky 1984
- Pronotal hump ridge-like (Fig. 21), gently and gradually descending to pronotal surface immediately at posterior pronotal bor- der (Fig. 22, arrow)........................................................... Lithax musaca Malicky 1972