1892] 



SPECIES OF EARTHWORMS. 



669 



be (woodcut, fig. 1) ; these setse are also absent from the xviith and 

 from the xixth segments, or rather they are there replaced by the 

 penial setae. In all the species of Acanthodrilus, on the other hand, 

 which I have been able to examine, the ventral setse are not missing 

 from the xviiith segment, though they are not present on the xviith 



Fig. 1. 



Ai Al 



Segments bearing atrial and sperm-duct pores in a number of Acantbodrilids. 



A. Octochcetus antarcticus ; B. Acantliodrilios capensis ; C. Benhamia (any 

 species); D . Acanthodrilus smithi ; E. Acanthodrilus novm-zelandice. 



At. atrial pores ; J , sperm-duct pores ; the groove connecting the atrial pores 

 and the setse is indicated ; penial setse are omitted in D and E. The 

 segments are numbered. 



and xixth segments, being there replaced by the penial setae ; this 

 is also the case with the genus Octochcetus; in two of the species 

 of that genus at any rate, viz. 0. multiporus and 0. antarcticus 

 (woodcut, fig. 1), the ventral pair of setse of segment xviii. are 

 Proc. Zool. Soc— 1892, No. XLV. 45 



