RIIINODRILUS TENKATEI. 103 



dular developmeut , but aloug the edge of the ventral 

 side between the dorsal and ventral series of setae a glan- 

 dular ridge occurs, consisting of 7 tubercula pubertatis. 

 In Perrier's Rhiiwdrilus paradoxus the clitellum enteuds 

 from the 19th — 21st segment and is also characterized by 

 a ridge-shaped thickening on each side of the ventral sur- 

 face. In the 26*1' segment each ventral pair of setae is 

 surrounded by a glandular wall and the setae themselves 

 are modified in penial setae; therefore I suppose this seg- 

 ment contains the male genital orifices , though I was 

 unable to recognize them with certainty and though in R. 

 parddoxus these pores are situated much more forward , 

 between the 19tii and 20*^ ring. The penial setae (fig. la) are 

 not only longer, but also straighter than the other ones ; the 

 usual thickening does not lie in the middle of the bristles , 

 but in their inferior third and they have a length of 0.9 

 m.m., whereas the ventral setae are 0.6 m ra., and the dorsal 

 ones only 0.42 m.m. in length. The distal end of each penial 

 seta is peculiarly provided with semi-lunate excavations ; in 

 the ordinary setae (fig. 76) these are not so apparent and only 

 faint lines are visible. In one specimen the ventral setae 

 of the 17*11, X'^Va. and 19*11 segment were also replaced by 

 a fascicle of four bristles , quite similar to the penial setae. 

 As was demonstrated by Hering') and Beddard^) in 

 Lumhricus and Acanthodrilus the modification of the setae 

 is neither always confined to the setae in the neighbour- 

 hood of the genital orifices. 



In dissecting our worm ^) I was surprized by the enor- 

 mous development of the nephridia in the anterior seg- 

 ments of the body (fig. 5) ; the fifst pair of them , belonging to 

 the third segment, is the largest and consists of two vast 

 glands , situated at the inferior side of the oesophagus and 

 entending into the 9tli ring. The six following pairs of 



1) Zeitschr. wissensch. Zoölogie. Bd. VIII, p. 418. 



2) Proc. Zool. Soc. 1886, p. 173. 



3) A more detailed account of the anatomy of this species will be published 

 elsewhere. 



I*3^otes from the Ley den IMuseuEn , Vol. IX. 



