1907. J WORMS OF THE FAMILY EUDRILID.E. 419' 



sperraathecal diveiticula. The slender spermatheca just hi fi'ont 

 of the tei-minal section of the male efferent apparatus divides into 

 two branches, which diverge at right angles and run dorsally, this 

 portion of the spermatheca forming a tube more than 5 mm. in 

 length. Towards the dorsal median line the tube of each side 

 tuiiis back upon itself after emitting a very shoi-t but slightly 

 swollen diverticulum ; the recurrent branch runs alongside of 

 the outgoing branch, the two forming a loop which suggests at 

 first sight a nephridium. It is indeed not very much thicker 

 than the nejohridia. The returning branch then, having arrived 

 at the level of the point whence it departed, dorsaily turns at 

 right angles and joins its fellow a little in front of the external 

 aperture, which is quite inconspicuous. This peculiar origin of 

 the diverticulum on each side is exactly matched in the three 

 species to which the present is evidently allied, viz. Pohjtoreuius 

 usindjaensis, P. kirimaensis, and P. sylvestris. But in all of the 

 three species mentioned the diverticulum itself is of some 

 considerable calibre. Polytoreutus kirimaensis comes nearest to 

 the present species in that the diverticulum is smaller than in the 

 other two. But even in this species it is much larger than in 

 P. ruioenzorii. There is thus no difficulty in discriminating 

 Polytoreutus rtoivenzorii by the structure of the female efiiei'ent 

 and copulatory apparatus. It is very interesting to notice that 

 Polytoreutus rinvenzorii also shows points of resemblance to P. 

 sylvesti'is and P. kirimaensis (but apparently not to P. usindjaensis) 

 in the structure of the male efferent apparatus, which has been 

 already described. There seems to be no doubt that these 

 four species form a little group of Polytoreutus ; but it is not 

 possible in my opinion to separate them off from the other species 

 as a geniis or even a subgenus, at least at present. 



It is clear from the above account that Polytoreutus ritivenzo7'ii 

 comes nearest to P. sylvestris of Michaelsen. It is only, as I think, 

 with this species that we have to reckon in determining the dis- 

 tinctness or otherwise of the Polytoreutus which I regard as new. 



The most plain differences from this species are to be seen in 

 the small size of the spermathecal diverticula and the very 

 reduced length in front of the undivided portion of the posterioi'ly 

 fused spermathecal sacs. It may be thus defined : — 



Polytoreutus rawenzorii. 



Length 70-80 mm. ; hreadjth 4-5 mon. Distance hetiveen setce 

 of ventral ]xcir three times that hetioeen setce of lateral pair. 

 Outer seta of lateral ^«'ir absent on clitellar segments. Clitellum. 

 saddle-shaped. Male pore xvii./xviii.; spermathecal pore xinii./xi.x. 

 JVo genital area behind piores. Spermathecal sac bifurcate for a 

 short distance in front ; posterior diverticida very small ; oviduct 

 between spermathecal sac and receptacidum very long. Right 

 sperm-sac longer than left. Sj^iermiducal glands giving off duct in 

 front of i^roximal end gland, mu^h furrowed. Copulatory chambers 

 present. 



