416 ME. F. E. BEDDARD ON NEW [Apr. 23, 



the individual setfe of the lateral pair. I have endeavoured 

 to make an exact study of the distribution of the setse upon 

 the clitellar segments, concerning which there is some but 

 not exhaustive information, of some other species of the genus 

 already described ; for this character seems to be one of probably 

 systematic value. On these segments I could only find one of the 

 tw^o setfe of the lateral pair, and the seta present Avas the inner- 

 most. I ought to mention that these statements depend upon a 

 microscopic examination of the entire cuticle stripped froin the 

 body, and not merely upon an inspection of the entire worm with 

 a lens. The apertures through which the sette are protruded are 

 so obvious that the failure to find one is strong evidence of its 

 absence. The ventral setfe, on the other hand, were present apon 

 the clitellar segments with the exception of the xviith, where only 

 the outer seta of the pair was present. Ventrally the clitellum is 

 not so strongly developed as it is laterally and dorsally, which facts 

 may be related to the presence or absence of setfe. 



The clitellum of Poly tor eidus noioenzorii is, like that of Poly- 

 toreutus sylvestris and some, but not all, other species, best 

 developed laterally and dorsally. Ventrally it is not so well- 

 developed, and here the intersegmental furrows are plainer than 

 laterally. It embraces segments xiii. to xvii., which is the usual 

 extent of the clitellum in this genus. 



The nepliridiojjores lie in front of the lateral pair of setfe, in 

 front of each pair, and not in front of any one seta of the pair 

 more particularly. They commence apparently in the foui'th 

 segment. A notable fact with reference to these pores is that 

 when the cuticle is stripped off — and I have mapped the pores by 

 this means — a considerable strip of the (as it would therefore 

 appear) chitinous lining of the duct of the nephridium is also 

 stripped off and protrudes from each aperture. I have not 

 noticed anything of this kind in other Oligochfeta. 



The oviduccd pores are quite conspicuous and lie upon the xivth 

 segment behind and to the outside of the nephridial row and 

 the lateral seta of that segment. The single onale pore is on the 

 border of segments xvii./xviii. and the spermathecal pore behind it 

 upon the interval xviii./xix. 



The internal anatomy of this species, so far as concerns the 

 alimentary and circulfitory organs, seems to agree with that of the 

 next species to be described and with the members of this genus 

 generally. 



The sperm-sacs are like those of Polytoreutus generally (but not 

 P. hettonianus) in being exceedingly long, and at their commence- 

 ment and for a long way back of much less diameter than they 

 are more posteriorly. The sacs extend for more than 30 segments 

 back from theu^ point of origin. That of the right side is fifteen 

 segments longer than the shorter sperm-sac of the left side. The 

 difierence in length in this species is more pronounced than in 

 that next to be described. The dilated chambers at the beginning 

 of the sperm duct immediately after it leaves the funnel are 



