1902.] NEW SPECIES OP EARTHWORMS. 195 



forward than the xviith segment. This, as will be seen from a 

 comparison of the drawings exhibited (c/. text-figs. 46 and 48, 

 p. 192), is a striking difference between Polytoreutus montis- 

 kenycB and P. Jcenyaensis. The male orifice itself is not so con- 

 spicuous as in P. kenyaensis, and the female pore is much less so ; 

 it lies between segments xviii./xix. 



The outline of the perigenital ridge is not so complete as in the 

 last species. , Antei'iorly it is oval in contour, leaving a, consider- 

 able ventral area of that shape between the two sides. The riglit 

 and left folds apjDroach each other gradually, and about the xxiiird 

 segment are in practical contact, a furi'ow only being left between 

 them. The shape of the genital area is thus more like a racquet 

 than a violin. As I have already explained in the case of 

 P. kenyaensis, the perigenital lidges of the present species are 

 subject to some variation in their extent. But the mean about 

 which the variation plays is a segment further back than in 

 P. kenyaensis. In 26 individuals the ridges ended either upon 

 segment xxv. or upon segment xxvi. Ten of these I refer to the 

 latter category ; bvit it is a little difficult to be accurate in drawing 

 a hard and fixed line, since the groove sometimes ended upon the 

 middle of the xxvith segment. I found no (mature) individual 

 in which the genital area was of less extent ; but in one specimen 

 only it reached to the end of segment xxvii. 



Text-fiff. 49. 



Ventral view of genital segments of Folytoreutus montis-lcenyw. 

 JP, white cushion-like thickening. 



The only other external character to which I have to call 

 attention, is the very occasional presence of a white cushion-like 

 thickening of limited extent in the ventral median line of seg- 

 ments XX. and xxi. I only observed this character to l^e well 



13* 



