1. Neither anal spines nor spiniform chaetae present on Abd. VI (Fig. 51)........................................... 2
- Anal spines or spiniform chaetae present on Abd. VI (Figs 45–50).............................................. 10
2. AIIIO with four papillae (Figs 3, 33)...................................................................... 3
- AIIIO with five papillae (Figs 17, 26, 40)................................................................... 5
3. Th. tergum I with 2+2 pso, VT chaetae as 0+0/6+6/1+1 (see Sun et al. 2010), formula of dorsal pso: 32/233/33343, formula of ventral pso: 11/000/0100.... T. cryptopyga (Denis, 1931) sensu Najt & Weiner, 1997); Neotropics, Pacific islands, Indonesia
- Th. tergum I with 1+1 or without pso, VT chaetae as 1+1/6+6/2+2............................................... 4
4. Formula of dorsal pso: 32/021/33343 (Fig. 31), Abd sterna I–IV without pso (Fig. 37), formula of modified chaetae of MVO: 0,4 l,3 l,4 l,0,0 (Fig. 37)............................................... T. stepensis sp. nov.; Russia: Southern Siberia
- Formula of dorsal pso: 32/122/33343 (Fig. 1), Abd. sterna I–IV with 0 110 pso respectively (Fig. 8), formula of modified chae- tae of MVO: 0,4 l,3 l,2 l,0,0 (Fig. 8)..................................... T. aspinata sp. nov.; Russia: Southern Siberia
5. Th. tergum I without pso or with 1+1 pso................................................................... 6
- Th. tergum I with 2+2 or 3+3 pso......................................................................... 8
6. Formula of dorsal pso: 32/122/33343 (Fig. 38), subcoxa 1 of legs I–III with 2, 2 and 2 pso respectively, MVO present, formula of modified chaetae: 0,4l,4l,0,0,2–4l (Fig. 44)............................. T. weineri sp. nov.; Russia: Southern Siberia
- Formula of dorsal pso: 32/022/33343 (Figs 9, 16), subcoxa 1 of legs I–III with 1, 1 and 1 pso respectively, MVO absent.... 7
7. Pso formula on Abd. sterna I–IV: 0 111 (Fig. 23), subcoxae 1 of first pair of legs with 3 chaetae (Fig. 16).................................................................................. T. sibirica sp. nov.; Russia: Southern Siberia
- Pso formula on Abd. sterna I–IV: 0 110 (Fig. 15), subcoxae 1 of first pair of legs with 2 chaetae (Fig. 9)................................................................................... T. sayana sp. nov.; Russia: Southern Siberia
8. Th. tergum I with 3+3 pso (formula of dorsal pso: 42/333/33332), VT with 4+4 distal chaetae...................................................................................... T. hoguei (Palacios-Vargas & Diaz, 1996); Mexico
- Th. tergum I with 2+2 pso (formula of dorsal pso: 32/233/33343), VT with 6+6 distal chaetae......................... 9
9. Pso formula on Abd. sterna I–IV: 0 112, subcoxae 1 of legs I, II and III with 4, 4, 4 chaetae respectively, MVO absent.............................................................................. T. franzi (Stach, 1946); Austria, Italy
- Pso formula on Abd. sterna I–IV: 0 111 (Fig. 30), subcoxae 1 of legs I, II and III with 3, 3, 3 chaetae respectively (Fig. 24), MVO present, formula of modified chaetae: 0,4 l,4 l,0,0,4 l (Fig. 30).......... T. stebaevae sp. nov.; Russia: Southern Siberia
10. Spiniform chaetae present on Abd VI (Figs 49, 50), pseudocellar formula dorsally: 32/233/33343 and ventrally: 11/000/0112, subcoxae1 of legs I, II and III with 2, 2, 2 pso respectively................................................................................................ T. tovtrensis (Kaprus’ & Weiner, 1994); Ukraine, European part of Russia
- Anal spines present on Abd VI (Figs 45–48)............................................................... 11
11. AIIIO with four papillae............................................................................... 12
- AIIIO with five papillae............................................................................... 15
12. Th. tergum I without pso, posterior cephalic pso 3+3 (pso formula dorsally: 33/033/333(4)43 and ventrally without pso), sub- coxae 1 of legs I, II and III without pso............................... T. biquaternata Sun & Li, 2015 (2015b); China
- Th. tergum I with pso, posterior cephalic pso 2+2........................................................... 13
13. Th. tergum I with 2+2 pso, Abd. tergum IV with 4+4 pso (pso formula dorsally: 32/233/33343, pso formula ventrally: 11/000/ 0112), Abd. VI with two median chaetae a0 and m0........................ T. xihuensis Sun & Li, 2015 (2015a); China
- Th. tergum I with 1+1 pso, Abd. tergum IV with 3+3 pso..................................................... 14
14. Formula of dorsal pso: 32/122/22332, ventrally on head 1+1 pso present in anteromedial position, Th. tergum I with 5+5 chae- tae................................................................. T. butrosi (Christiansen, 1956); Lebanon
- Formula of dorsal pso: 32/11(3)1(2)/22(3)2(3)2(3)3, ventrally on head 2+2 pso present, Th. tergum I with 6+6 chaetae......................................................... T. moniezi (Bagnall, 1935) sensu (Salmon 1959); Great Britain
15. Antennal base with four pso............................................................................ 16
- Antennal base with three pso........................................................................... 17
16. Formula of dorsal pso: 43(4)/233/44454 and ventral pso: 11/000/1112, subcoxae 1 of legs I, II and III with 2,2,2 pso respec- tively............................................... T. halophila (Bagnall, 1937) sensu Fjellberg 1998; Palearctic
- Formula of dorsal pso: 42/233/33333 and ventral pso: 10/000/0112, subcoxae 1 of legs I, II and III with 1,1,1 pso respectively....................................................................... T. tamurai (Yue & Yin, 2000); China
17. Posterior cephalic pso 3+3 (formula of dorsal pso: 33/022/33343), PAO with 32 vesicles, size of body 1.7– 2 mm,........................................................ T. alborufescens (Vogler, 1895) sensu Gisin (1957); Western Europe
- Posterior cephalic pso 2+2............................................................................. 18
18. Th. tergum I without pso............................................................................... 19
- Th. tergum I with pso................................................................................. 22
19. Th. terga II and III without pso (formula of dorsal pso: 32/000/32332), unguiculus equals 0.5 inner edge of unguis, Abd. VI with two median chaetae a0 and m0............................ T. lagunensis (Palacios-Vargas & Diaz, 1995); Mexico
- Th. terga II and III with 3+3 or 2+2 pso each, unguiculus at least as long as inner edge of unguis, Abd. VI with median chaetae m0................................................................................................ 20
20. Th. terga II and III with 3+3 pso (formula of dorsal pso: 32/033/33333), formula of ventral pso: 11/000/0001, distal tibiotarsal whorl with 7 chaetae, VT chaetae as 0+0/5–6+5–6/0+0................................... T. lolae Arbea, 2017; Spain
- Th. terga II and III with 2+2 pso each..................................................................... 21
21. Formula of dorsal pso: 32/022/33332, PAO with 30–38 vesicles.............. T. kirgisica (Martynova, 1971); Kyrghyzstan
- Formula of dorsal pso: 32/022/22223, PAO with 20–22 vesicles................. T. bagnalli (Salmon, 1959); Great Britain
22. Th. tergum I with 1+1 pso.............................................................................. 23
- Th. tergum I with 2+2 pso.............................................................................. 32
23. Th. terga II and III with 2+2 pso each (pso formula on Abd. terga I–V: 33343).................................... 24
- Th. terga II and III with 3+3 pso each..................................................................... 26
24. Subcoxae1 of legs I, II and III with 1,1,1 pso respectively, VT with 1+1 anterior chaetae; Abd. ventral pso formula 11/000/ 0 100......................................................... T. reducta Sun, Chen & Deharveng, 2010; China
- Subcoxae1 of legs I, II and III with 2, 2, 2 pso respectively, VT without anterior chaetae, Abd. ventral pso formula another. 25
25. Abd. VI with two median chaetae a0 and m0, 3+3 axial chaetae on Abd. terga I–III, 3+3 chaetae between posterior inner pso on head, unguiculus equals 0.4 inner edge of unguis and with inner basal lamella................................................................................................... T. bapen Sun, Chen & Deharveng, 2010; China
- Abd. VI with one median chaetae m0, 2+2 axial chaetae on Abd. terga I–III, 4+4 chaetae between posterior pso on head, basal chaetae on ventral tube as 2+2, unguiculus equals 0.7 inner edge of unguis and without inner basal lamella............................................................................ T. guangdongensis Sun & Li, 2015 (2015a); China
26. Chaetae d0 absent on head............................................................................. 27
- Chaetae d0 present on head............................................................................. 28
27. Abd. sternum IV with 2+2 pso (pso formula on Abd. sterna I–IV: 0112), pso formula on Abd. terga I–V: 33334, subcoxae1 of legs I, II and III with 1,1,1 pso respectively........................ T. jailolonis (Yoshii & Suhardjono, 1992); Indonesia
- Abd. sternum IV without pso or 1+1 pso (pso formula on Abd. sterna I–IV: 0001), pso formula on Abd. terga I–V: 33343, subcoxae1 of legs I, II and III with 2,2,2 pso respectively............. T. problematica Sun, Deharveng & Wu, 2013; China
28. Distal tibiotarsal whorl with 7 chaetae, pso formula ventrally: 10/000/0112, subcoxae1 of legs I, II and III with 1,1,1 pso respectively....................................... T. petaloides (Rusek, 1981); Irak, New Caledonia, Hawaii, China
- Distal tibiotarsal whorl with 9 chaetae, ventral pso formula another............................................. 29
29. Subcoxae1 of legs I, II and III with 2, 2, 2 pso respectively, VT without anterior chaetae, pso formula on Abd. sterna I–IV: 0 111.......................................................... T. grandis Sun, Chen & Deharveng, 2010; China
- Subcoxae1 of legs I, II and III with 1, 1, 1 pso respectively, VT with 1+1 anterior chaetae, pso formula on Abd. sterna I–IV another............................................................................................. 30
30. Abd. sternum IV without pso (ventral pso formula: 11/000/0000), labial papillae of AC type....................................................................... T. thalassophila (Bagnall,1937) after Sun et al., 2010; Northern Europe
- Abd. sternum IV with 1+1 or 2+2 pso.................................................................... 31
31. Formula of ventral pso: 11/000/0001, pso formula on Abd. terga I–V: 33343, Abd. VI with one median chaetae a0, unguiculus reduced to small blunt process..................................... T. brevisetosa Sun, Gao & Potapov, 2014; China
- Formula of ventral pso: 11/000/0001(2), pso formula on Abd. terga I–V: 3,3–4,3,4–6,3–4, Abd. VI with two median chaetae a0 and m0, unguiculus equals 0.5 inner edge of unguis.......................................................................................... T. debilis (Moniez, 1890) after Sun et al., 2010, (form a); Western and northern Europe
32. Abd. tergum IV with 3+3 pso (formula of dorsal pso: 32/233/33333)............................................ 33
- Abd. tergum IV with more than 3+3 pso................................................................... 37
33. PAO with about 45 vesicles, Abd. tergum I with 9+9 chaetae, AS equals 0.4 unguis, formula of modified chaetae of MVO: 14 s,0,0,0,0,0................................................................ T. ishikawai (Yosii, 1956); Japan
- PAO with not more than 30 vesicles, Abd tergum I with less chaetae, AS more than 0.7 length of unguis............... 34
34. Unguiculus with basal lamella, approximately as long as inner edge of unguis, VT chaetae as 1+1/6+6/1+1..................................................................................... T. guineaensis (Salmon, 1965); Guinea
- Unguiculus without basal lamella, approximately equals 0.7 of inner edge of unguis................................ 35
35. Abd. sternum IV without pso (formula of ventral pso: 11/000/1120), Th. tergum I with 7+7 chaetae, VT chaetae as 1+1/6+6/ 2+2............................................................... T. yodai (Yosii, 1966); Nepal, China, Japan
- Abd. sternum IV with 2+2 pso, Th. tergum I with less chaetae................................................. 36
36. Formula of ventral pso: 10/000/1112, subcoxae1 of legs I, II and III with 2,2,2 pso respectively, chaetae on VT as 0+0/6+6/2+2...................................................................... T. yolandae (Izarra, 1971); Venezuella
- Formula of ventral pso: 10/000/0112, subcoxae1 of legs I, II and III with 1,2,2 pso respectively, VT chaetae as 1+1/5+5/2– 3+2–3................................................................. T. tamdaona (Nguyen, 1995); Vietnam
37. Abd. tergum V with 2+2 pso,........................................................................... 38
- Abd. tergum V with 3+3 or 4+4 pso...................................................................... 39
38. Formula of ventral pso: 11/000/0001, formula of dorsal pso: 32/233/3333(4)2, AS equals 0.5 unguis............................................................................................... H. orientalis (Stach, 1964); China
- Formula of ventral pso: 10/111/0000, formula of dorsal pso: 32/233/33342, AS equals 0.7 unguis................................................................................................ T. ghatensis (Prabhoo, 1971); India
39. Subcoxae 1 of legs I, II and III with 1,1,1 pso respectively, formula of dorsal pso: 32/233/3,3–4,3,4–6,3–4, formula of ventral pso: 11/000/0111(2)......................... T. debilis (Moniez, 1890) after Sun et al., 2010, (form b); Northern Europe
- Subcoxae 1 of legs I, II and III with 2(1),2,2 pso respectively, formula of dorsal pso: 32/233/33343.................... 40
40. Abd. sternum IV with 1+1 pso.......................................................................... 41
- Abd. sternum IV with 2+2 pso.......................................................................... 43
41. Formula of ventral pso: 11/000/0001, Abd. VI with two median chaetae a0 and m0, unguiculus equals 0.3 of inner edge of unguis....................................... T. sensilata (Thibaud & Massoud, 1979); Caribbean Islands, Mexico
- Formula of ventral pso: 11/000/0111..................................................................... 42
42. Th. tergum I with 5+5 chaetae, Abd. VI with one median chaetae a0, chaetae on VT as 1+1/6+6/1+1, AS equals 0.2 unguis.............................................................. T. pomorskii Sun, Chen & Deharveng, 2010; China
- Th. tergum I with 7–8+7–8 chaetae, Abd. VI with one median chaetae m0, chaetae on VT as 1+1/6–8+6–8/2+2, AS equals 0.7 unguis..................... T. duplopunctata (Strenzke, 1954) after Sun et al. (2013); Holarctic (arctic and boreal areas)
43. Ventrally on head 1+1 pso present, ungiuculus less than 0.2 of inner edge of unguis, AS equals 0.9 unguis................................................................................... T. thaibinhensis (Nguyen, 2001); Vietnam
- Ventrally on head 2+2 pso present, ungiuculus equals or bigger than 0.5 of inner edge of unguis...................... 44
44. Distal tibiotarsal whorl with 7 chaetae, ungiuculus equal 0.5 of inner edge of unguis, with basal lamella, AS equals 0.7 unguis.......................................................... T. tibiotarsalis Sun, Chen & Deharveng, 2010; China
- Distal tibiotarsal whorl with 9 chaetae.................................................................... 45
45. Abd. sternum I with 1+1 pso (pso formula on Abd. sterna I–IV: 1112), Th. tergum I with 7+7 chaetae, ungiuculus equals 0.7 of inner edge of unguis, without basal lamella, Abd. VI with one median chaetae m0... T. kwona (Thibaud & Lee, 1994); Korea
- Abd. sternum I without pso............................................................................. 46
46. Dorsally on head 3+3 chaetae between two posterior inner pso (Fig. 1).......................................... 47
- Dorsally on head 4+4 chaetae between two posterior inner pso................................................. 56
47. Th. tergum I with 5+5 chaetae........................................................................... 48
- Th. tergum I with more than 5+5 chaetae.................................................................. 51
48. Abd. VI with two median chaetae a0 and m0............................................................... 49
- Abd. VI with one median chaetae a0..................................................................... 50
49. Ungiuculus with inner basal lamella, AS equals unguis on distinct papillae, S-chaetae differentiated, their formula dorsally: 11/ 0 1 1/ 221120...................................................... T. tiani Sun, Chen & Deharveng, 2010; China
- Unguiculus without inner basal lamella, AS equals 0.6 unguis on indistinct papillae, S-chaetae not differentiated............................................................................ T. linzhiensis Sun & Li, 2015 (2015a); China
50. AS equals 0.7 unguis, S-chaetae on body not differentiated, size of body 0.9–1.4 mm.......................................................................... T. zschokkei (Handschin, 1919) sensu Pomorski, 1998; Europe, Israel, Iran
- AS equals 0.3 unguis, S-chaetae on body differentiated, size of body 0.6–0.8 mm................................................................................................... T. hainamica Sun, Gao & Potapov, 2014; China
51. Abd. VI with two median chaetae a0 and m0............................................................... 52
- Abd. VI with one median chaetae a0 or m0................................................................ 55
52. Th. tergum I with 6+6 chaetae........................................................................... 53
- Th. tergum I with 7(8)+7(8) chaetae...................................................................... 54
53. Chaetae on VT as 0+0/6–7+6–7/0+0, 7 labial proximal chaetae present, inner basal lamella on unguiculus absent, body size 1.2–1.7, formula of modified chaetae of: 0,6–12 l,7–10 l,0,0,0.................. T. qixiaensis Yan, Shi & Chen, 2006; China
- Chaetae on VT as 1+1/7+7/2+2, 6 labial proximal chaetae present, inner basal lamella on unguiculus present, body size 0.6– 0.85, formula of modified chaetae of MVO: 2 ih,0,0,0,0,0.............................. T. petiti Sun & Wu, 2013; China
54. Labial type AC, inner basal lamella on unguiculus absent, Abd. tergum IV without median chaetae, S-chaetae on body differentiated, formula of modified chaetae of MVO: 2 ih,0,0,0,0,0......................... T. bisetosa Sun & Wu, 2013; China
- Labial type A, inner basal lamella on unguiculus present, Abd. tergum IV with median chaetae m0, S-chaetae on body not differentiated, males unknown (parthenogenetic species)...... T. encarpata (Denis, 1931) sensu Fjellberg, 1998; Cosmopolitan
55. AS equals 0.4 unguis, VT with 5+5 distal chaetae, Abd. VI with one median chaetae a0, MVO absent.................. T............................................................... tenuis Babenko, 2007; Russia (Middle Siberia)
- AS equals 1.1 unguis, VT with 6+6 distal chaetae, Abd. VI with one median chaetae m0, formula of modified chaetae of MVO: 5 st,0,0,0,0,0...................................... T. macrospinata Sun & Wu, 2012; China, Russia (Far East)
56. Th. tergum I with 5+5 chaetae, chaetae on VT as 1+1/6+6/2+2, AS equals 0.5 unguis, MVO absent....................................................................... T. lifouensis (Thibaud & Weiner, 1997); New Caledonia, China
- Th. tergum I with 7(8)+7(8) chaetae, chaetae on VT as 1+1/7+7/2+2, AS equals 0.9–1.0 unguis, formula of modified chaetae of MVO: 2 ih,0,0,0,0,0................................................... T. qinlingensis Sun & Wu, 2013; China