Key to the genera of Ocnerodrilidae (from Fragoso & Rojas, 2009, extended)
1. Esophagus without extramural calciferous glands............................................................ 2
- Esophagus with extramural calciferous glands............................................................... 7
2. Gizzard absent (Hawaii)............................................................ Enicmodrilus Eisen, 1900
- Gizzard present....................................................................................... 3
3. Two gizzards, in VI and VII............................................................................. 4
- One gizzard in VII..................................................................................... 5
4. With dorsal pores and typhlosole; metandric (testes in XI), prostates in XVII, XIX, XX, XXI (India)........................................................................................................ Deccania Gates, 1949
- Without dorsal pores and typhlosole; holandric (testes in X and XI) (Mexico)........... Chacdrilus Fragoso & Rojas, 2009
5. Two pairs of prostates in XVII and XIX or three pairs of prostates in XVII, XIX and XX (India)....... Thatonia Gates, 1942
- One pair of prostates in XVII or two pair of prostates in XVII and XX............................................ 6
6. Holandric, prostates in XVII or XVII and XX (India, China, Myanmar)..................... Malabaria Stephenson, 1924
- Metandric, prostates in XVII (India)............................................... Aphanascus Stephenson, 1924
7. Unpaired segmental calciferous glands.................................................................... 8
- Paired segmental calciferous glands...................................................................... 10
8. Calciferous glands in IX and X (India).................................................... Curgiona Gates, 1941
- Calciferous gland only in IX............................................................................. 9
9. Two pairs of prostatic glands in XVII and XIX; gizzard generally absent (Tropical Africa, Brazil?, some peregrines)...................................................................................... Gordiodrilus Beddard, 1892
- Three pairs of prostatic glands in XVII–XIX (Africa).................................... Nannodrilus Beddard, 1894
10. Calciferous glands in IX and X.......................................................................... 11
- Calciferous glands in VIII or IX or XI.................................................................... 14
11. Metandric (Seychelles Islands)...................................................... Maheina Michaelsen, 1897
- Holandric........................................................................................... 12
12. One pair of prostates in XVII or XVIII.................................................................... 11
- Two pairs of prostates, one pair in XVII and the other in XIX (Brazil).............................. Bauba Righi, 1980
13. Prostates in XVII (Brazil).......................................................... Paulistus Michaelsen, 1926
- Prostates in XVIII (Argentina, Ecuador, Peru)................... Quechuona Gates, 1941 (= Quechua Michaelsen, 1923)
14. Calciferous glands in VIII or XI......................................................................... 15
- Calciferous glands in IX............................................................................... 16
15. Calciferous glands VIII (Brazil)....................................................... Brunodrilus Righi, 1971
- Calciferous glands in XI (Brazil)................................................... Exisdrilus Righi et al., 1978
16. With gizzards........................................................................................ 17
- Without gizzards..................................................................................... 27
17. Two pairs of testes (Holandric).......................................................................... 18
- One pair of testes..................................................................................... 22
18. Two gizzards, one in VI and another in VII (Ecuador).......................................... Xibaro Righi, 1981
- One gizzard......................................................................................... 19
19. Gizzard in V, genital markings as protuberances in AB line (Brazil)............. Brasilisia Hernández-García et al., n. gen.
- Gizzard not in 5, no genital markings as protuberances in AB line.............................................. 20
20. Gizzard in VI (Brazil)................................................... Arraia Hernández-García et al., n. gen.
- Gizzard in VII or VIII................................................................................. 21
21. Gizzard in VII (Brazil).......................................................... Dariodrilus Righi et al. 1978
- Gizzard in VIII (West Africa)........................................................ Dorgiodrilus Gates, 1962
22. Proandric (one pair of testes in X)....................................................................... 23
- Metandric.......................................................................................... 25
23. One pair of spermathecae.............................................................................. 24
- Two pairs of spermathecae (South America, some peregrines)............................. Eukerria Michaelsen, 1935
24. Prostatic and male pores combined (Argentine)........................................... Gatesia Jamieson, 1962
- Prostatic and male pores separated (Argentine, Bolivia, Brazil)............................... Belladrilus Righi, 1984
25. Two gizzards, one in VI, one in VII...................................................................... 26
- Three gizzards, in VI–VIII (Brazil)....................................................... Lourdesia Righi, 1994
26. Solid calciferous glands (without lumen) (Dominican Republic)............................. Temanonegia Gates, 1979
- Calciferous glands with large, central lumen (Central America, Africa, one peregrine)........... Nematogenia Eisen, 1900
27. Proandric........................................................................................... 28
- Holandric........................................................................................... 29
28. One pair of prostates in XVII (Brazil, Paraguay).......................................... Haplodrilus Eisen, 1900
- Two pairs of prostates, one pair in XVII, one pair in XIX (Brazil).......................... Kerriona Michaelsen, 1924
29. One pair of spermathecal pores.......................................................................... 30
- Three pairs of spermathecal pores (in VII–IX) (Equatorial Guinea)...................... Diaphorodrilus Cognetti, 1910
30. Spermathecal pores in 6/7 or 7/8......................................................................... 31
- Spermathecal pores in 8/9 or 9/10........................................................................ 32
31. Spermathecal pores in 6/7 (Ghana)...................................................... Tazelaaria Gates, 1962
- Spermathecal pores in 7/8 (Guyana, Brazil)................................................. Liodrilus Eisen, 1900
32. Trabeculated calciferous glands, complete or only in part (Africa, Mexico, Central and South America, some peregrines)................................................................................... Phoenicodrilus Eisen, 1895
- Calciferous glands with large central lumen................................................................ 33
33. Spermathecae with diverticula (Africa).......................................... Pygmaeodrilus Michaelsen, 1890
- Spermathecae without diverticulum (Central and South America, one peregrine)................ Ocnerodrilus Eisen, 1878