Eutyphoeus Michaelsen, 1900

Updated key to the species of Indian Eutyphoeus Michaelsen, 1900 View in CoL (revised after Julka 1988 and Tiwari et al. 2021)

1. Holandric; seminal vesicles in ix and xii .......................................................................................... 2

– Metandric; seminal vesicles in xii .................................................................................................. 16

2. Spermathecal pores at a or ab........................................................................................................... 3

– Spermathecal pores at b or lateral to b.............................................................................................. 5

– Spermathecal pores at bc.................................................................................................................. 8

3. Spermathecae unidiverticulate ............................ E. manipurensis manipurensis Stephenson, 1921

– Spermathecae bidiverticulate ............................................................................................................ 4

– Spermathecae polydiverticulate ............................................. E. quadripapillatus Michaelsen, 1907

4. Spermathecal pore at a............................ E. mizoramensis Julka, Ramanujam & Lalthanzara, 2005

– Spermathecal pore at ab.................................................................................................................... 9

5. Vestibulate ......................................................................................................................................... 6

– Avestibulate ......................................................................... E. morehensis Tiwari & Yadav sp. nov.

6. Lateral intestinal caecae present ....................................................................................................... 7

– Lateral intestinal caecae absent ....................... E. tawi Tiwari, Lone, Thakur, James & Yadav, 2021

7. Genital markings present ................................................................................................................ 13

– Genital markings absent .......................................................................... E. marmoreus Gates, 1933

8. Spermathecae bidiverticulate .......................................................... E. annandalei Michaelsen, 1907

– Spermathecae polydiverticulate ..................................................... E. incommodus ( Beddard, 1901)

9. Clitellum annular ............................................................................................................................ 10

– Clitellum not annular .......................................................................................................................11

10. Genital marking gland absent, lateral intestinal caeca dorsally directed ............................................ ....................................................... E. phawngpuiensis Tiwari, Lone, Thakur, James & Yadav, 2021

– Genital marking gland present, lateral intestinal caeca ventrally directed ......................................... ........................................................................................... E. lamdengensis Tiwari & Yadav sp. nov.

11. Penial setae present ........................................................................................................................ 12

– Penial setae absent ................................................................ E. shiroensis Tiwari & Yadav sp. nov.

12. Male pore under cuneate wedge-shaped papillae with fimbriated margin at b................................... ........................................................................................... E. kashongensis Tiwari & Yadav sp. nov.

– Male pore on circular porophores centered at b................. E. ukhrulensis Tiwari & Yadav sp. nov.

13. Genital marking gland around spermathecal duct in vii present .................................................... 14

– Genital marking gland around spermathecal duct in vii absent ...................................................... 15

14. Vestibula pentagonal shape, penial setae with blunt tip ...................................................................... ..................................................................................... E. yangoupokpensis Tiwari & Yadav sp. nov.

– Vestibula not-pentagonal shape, penial setae with pointed tip............................................................. ...................................................................................... E. tengnoupalensis Tiwari & Yadav sp. nov.

15. Preclitellar genital marking present ..................................... E. lokchaensis Tiwari & Yadav sp. nov.

– Preclitellar genital marking absent ..................................... E. baronongini Tiwari & Yadav sp. nov.

16. Avestibulate .................................................................................................................................... 17

– Vestibulate ....................................................................................................................................... 30

17. Spermathecae bidiverticulate .......................................................................................................... 18

– Spermathecae polydiverticulate ...................................................................................................... 28

18. Lateral intestinal caecae present ..................................................................................................... 19

– Lateral intestinal caecae absent ...................................................................................................... 24

19. Lateral intestinal caecae dorsally directed ...................................................................................... 20

– Lateral intestinal caecae ventrally directed ..................................................................................... 21

20. Genital marking glands present ........................................................................ E. lippus Gates, 1934

– Genital marking glands absent............. E. rihnimensis Rodingpuia, Lalthanzara, Julka, Chawngthu, Mathipi, Lalfelpuii, Kumar, Gurusubramaniun, Lalchhandama, Vanlalrovi & Chhakchhuak, 2024

21. Female pore single, on left side ...................................................................................................... 22

– Female pore paired ......................................................................................................................... 23

22. Penial setae ornamented, with tapering tip ............................................... E. gigas Stephenson, 1917

– Penial setae without ornamentation, with spoon shaped tip ............................................................... .......................................................................... E. serei Tiwari, Lone, Thakur, James & Yadav, 2021

23. Penial setae shaft slightly curved, tip thickened, pointed and claw-shaped ....................................... ............................................................................................................ E. turaensis Stephenson, 1920

– Penial setae serpentine, tip spoon-shaped with a small bulbous end .................................................. ................................................................................................ E. kwathensis Tiwari & Yadav sp. nov

24. Spermathecal pores at ab................................................................................................................ 25

– Spermathecal pores lateral to b....................................................................................................... 26

25. Genital markings preclitellar, segmental ...................................... E. comillahnus Michaelsen, 1907

– Genital markings postclitellar, intersegmental .............................................. E. festivus Gates, 1938

26. Genital markings paired, segmental on xvi .................................................................................... 27

– Genital markings unpaired, intersegmental on xv/xvi ....................... E. scutarius Michaelsen, 1907

27. Sessile genital marking glands present ............................................................................................... ............................................................. E. dhubriensis Ahmed, Julka, Banerjee & Marimuthu, 2023

– Sessile genital marking glands absent .......................................... E. assamensis Stephenson, 1926 *

28. Seminal vesicles in xii very long, extending posteriorly into xxxiii .................................................. ................................................................................................... E. pharpingianus Michaelsen, 1907

– Seminal vesicles in xii shorter, at the most extending into xx ........................................................ 29

29. Genital marking intraclitellar, on xvi ................................................ E. nainianus Michaelsen, 1907

– Genital marking intra and post-clitellar, on xiv–xv, xviii/xix–xxi/xxii ............................................... .......................................................................................................... E. nepalensis Michaelsen, 1907

30. Univestibulate ................................................................................................................................. 31

– Bivestibulate ................................................................................................................................... 32

31. Spermathecal pores at ab; penes conical .......................................................... E. kherai Julka, 1978

– Spermathecal pores at median half of bc; penes annular ...................... E. gammiei ( Beddard, 1888)

32. Penes annular .................................................................................................................................. 33

– Penes elongate ................................................................................................................................ 35

33. Genital markings present on xv, usually also on xvi ........................... E. orientalis ( Beddard, 1883)

– Genital markings present on xv–xvi absent .................................................................................... 34

34. Genital markings preclitellar on ix/x ................................................ E. aborianus Stephenson, 1914

– Genital markings pre- and post-clitellar on x/xi–xii/xiii, xviii/xix–xxi/xxii ....................................... ....................................................................................................................... E. callosus Gates, 1938

35. Spermathecal pores at ab................................................................... E. nicholsoni ( Beddard, 1901)

– Spermathecal pores at bc................................................................................................................ 36

36. Spermathecae bidiverticulate; genital markings pre-, intra- and post-clitellar .................................... ............................................................................................................... E. waltoni Michaelsen, 1907

– Spermathecae polydiverticulate; genital markings post clitellar or absent ......................................... ................................................................................................................. E. kempi Stephenson, 1914

* This study confirms that Eutyphoeus assamensis is an avestibulate and apenile species showing features that were previously unrecorded or unclear in earlier taxonomic descriptions ( Gates 1972; Julka 1988). While Julka (1988) provided a valuable categorization of the species based on the presence or absence of a vestibule, our examination of a mature, clitellate specimen of E. assamensis from our collection unequivocally confirms its avestibulate and apenile nature. This observation directly contrasts with potential ambiguities arising from Julka’s (1988) description, which may have been influenced by his reliance on aclitellate specimens where the full development of male genitalia, including the vestibule and penis, was incomplete. Consequently, our findings provide a crucial refinement of the existing taxonomic framework for the species, highlighting the importance of examining fully mature specimens for accurate species characterization, particularly concerning key reproductive structures like the vestibule and penis.