1	1111 coxal pores	Lithobius (Monotarsobius) monoforaminis Ma, Pei, Wu, Lin, Gai, 2012
–	At least 1222 coxal pores	2
2	4–6 coxal pores	3
–	At most 3 coxal pores.	5
3	8–11 ocelli on each side of cephalic fig Lithobius (Monotarsobius) crassipes L. Koch, 1862
–	5–6 ocelli on each side of cephalic fig	4
4	5555 coxal pores, 3+3, 4+4, 3+4 spurs of female gonopods	Lithobius (Monotarsobius) ramulosus (Takakuwa, 1941)
–	3343 or 4564 coxal pores, 2+2 spurs of female gonopods	Lithobius (Monotarsobius) mroczkowskii Matic, 1970
5	Four ocelli on each side of cephalic fig, 17+17 antennal articles	Lithobius (Monotarsobius) crassus (Loksa, 1965)
–	Five or more ocelli on each side of cephalic fig, antennal not less than 18+18 articles	6
6	Tömösváry’s organ smaller than adjoining ocellus	7
–	Tömösváry’s organ larger than adjoining ocellus or about same in size	8
7	With anterior spine on prefemur on legs 14–15	Lithobius (Monotarsobius) zhangi sp. n.
–	Without anterior spine on prefemur on legs 14–15	Lithobius (Monotarsobius) songi Pei, Ma, Shi, Wu, Zhou, 2011
8	male legs 15 presence secondary sexual characters, the terminal claw of the female gonopods tridentate	9
–	male legs 15 absence secondary sexual characters, the terminal claw of the female gonopods not tridentate	10
9	Ventral plectrotaxy 01210, dorsal plectrotaxy 10200 in the 14th legs	Lithobius (Monotarsobius) riedeli Matic, 1970
–	Ventral plectrotaxy 01321, dorsal plectrotaxy 10310 in the 14th legs	Lithobius (Monotarsobius) dziadoszi Matic, 1970
10	Tömösváry’s organ larger than the biggest ocellus	Lithobius (Monotarsobius) holstii (Pocock, 1895)
–	Tömösváry’s organ smaller than the biggest ocellus	11
11	With one protuberance at the end of the dorsal of tibia of 15 legs in male	Lithobius (Monotarsobius) ferganensis (Trotzina, 1894)
–	Without protuberance at the end of the dorsal of tibia of 15 legs in male	12
12	With posterior spine on prefemur on legs 11–13	Lithobius (Monotarsobius) obtusus (Takakuwa, 1941)
–	Without posterior spine on prefemur on legs 11–13	Lithobius (Monotarsobius) subspinipes Ma, Pei, Zhu, Zhang, Liu, 2009