598 OLIGOCHAETA 



penial setae is very unlike that of the penial setae of the two remaining species 

 they are finely denticulate near to the free extremity. 



(a) Platydrilus lewaensis, Michaelsen. 

 p. lewaensis, Michaelsen, loc. cit., p. ii. 



Definition. Length, -iopmm.; hreadth, 2^ mm.; number of segments, 204. Skin unpigmented. 



Penial setae without sculpturing, sharply 'pointed, at distal extremity. Hab. — Lewa, 



U. Africa. 

 This species is more fully described by Michaelsen than are either of the two 

 remaining species. In addition to the points of specific importance mentioned in the 

 above diagnosis, the following are probably of specific value : the setae are strictly 

 paired ; the interval between the dorsal setae is about half the circumference of the 

 body; the distance between the pairs of setae of a given segment is about equal, in 

 general two or three times as great as that between the two setae of a pair. In 

 the hinder region of the body the setae are larger than the setae of the anterior 

 segments. The septa which separate segments vi/x are strongly thickened. Contrary 

 to what is found in all other Eudrilidae, except Eudriloides, there are dorsal pores 

 present; these commence between segments vi/vii. The nephridiopores open in front 

 of the lateral setae. No receptaculum was found. 



(3) Platydrilus megachaeta, Michaelsen. 

 p. megaehaeta, Michaelsen, loc. cit., p. 14. 



Definition. Length, 1^0 mm. ; breadth, 2-^mm.f number of segments, 182. Penial setae 



without sculpturing, but more slender than in P. lewaensis, and without a pointed 



extremity. Hab. — Makahalla, E. Africa. 



This species differs from the last also in the presence of integumental pigment ; 



the colour is described as being of a clear grey becoming yellowish in front. The 



setae are .strictly paired in the front segments ; behind the clitellum they get further 



apart, and at the same time become longer and thicker. There are no visible dorsal 



pores. The clitellum extends from the middle of the fourteenth to the middle of the 



seventeenth segment. 



Genus Nembrtodbilus, Michaelsen. 



Depinitiow. Setae strictly paired. Clitellum, XIII-XVIII. Male pores upon 

 XVII/XVIII. On XIII a pair of pores leading into interior of that segment. 



