EXPLANATION OF PLATE XVIIL 



Fig. 23. — Octochaelus castellanus ; penial setae, of two types, a 

 and h ; X about 360, 



., 24. — The same: copulatory setae of segment viii, X about 

 300. 



,, 25. — Octochaetus harkudev.sis ; male genital region of a speci- 

 men showing well-marked copulatory papillae. 



,, 26. — The same ; two spermathecae, a and 5, showing varia- 

 tions in form. 



.. 27. — The same ; portion of shaft of copulatory seta of seg- 

 ment viii. 



„ 28. — Eutyphociis gigtis ; region of male apertures. 



,. 29. — The same ; spermatheca ; the dotted lines indicate the 

 portion of the under surface which is attached to the 

 body-wall. 



,, 30. — The same ; penial seta, the distal end ;X 160. 



,, 31. — Eudichogaster chittagongensis ; genital region. 



,, 32. — The same ; two spermathecae ; .'?, as seen in the dissected 

 specimen ; 6, a second, seen bj^ transparency under 

 the low power. 



,, 33. — The same ; outline of penial setae. 



