612 OLIGOCHAETA 



This species is also a very distinct form which cannot be confused with any 

 other species. Its colour appears to be not unlike that of P. violaceus, but paler. 

 The setae seem to be, to some extent, defective upon the segments which bear the 

 genital pores. The single median papilla lying behind the clitellum projects somewhat ; 

 it has no definite boundary like that which marks the papilla of P. violaceus. The 

 male pore is placed a little further back than this aperture in other species ; it opens 

 between segments xvii/xviii; the female pore is on the eighteenth. There are six 

 specially thickened septa, the first of which divides segments v/vi. The sperm-sacs 

 differ from those of other species in that the anterior slender region of the sac is 

 confined to the eleventh and twelfth segments ; they reach to about the twenty- 

 seventh. In an immature example of this species I found the sperm-sac to show 

 the same characters as those which have been described ; this, of course, increases 

 the probability of that description being of a normal worm ; but in this specimen 

 the two sacs were fused at their posterior extremity; this individual was furthermore 

 remarkable for the fact that the dorsal vessel was double in segments viii-xii. It 

 may, therefore, be conceivably a distinct species. 



(6) Polytoreutus gregorianus (NEW SPECIES). 



Definition. Length, 212 mm. ; diameter, 7 mm.; number of segments, 440. Clitellum. 



XIII-XVIII. Spermathecal pore XVII/XVIII. Male pore, XIX. On fifteen segments 



following male pore a ventral median glandular thickening. Spermathecal sac with two 



long diverticula at anterior end and two shorter ones at posterior end. Had. Giriama, 



near Fuladoya, E. Africa. 



Of this species there is a single example in the British Museum, which was collected 

 by Dr. J. W. Gregory at the above-mentioned locality. The ventral glandular 

 thickening on segments xx-xxxv, resembles that of Polytoreutus. The glandular 

 patches, which are of a deeper brown than the surrounding integument, occupy not 

 quite all the space between the two outermost of the ventral seta couples ; they are 

 sharply divided by the intersegmental furrows. As to internal characters the species 

 is distinguished from others by the form of the spermathecal sac. The median part 

 of the sac is wide, but shows no external traces of division into two. Anteriorly 

 it divides in the usual way into two large lateral diverticula which almost meet 

 on the dorsal surface of the intestine. The ovarian canal springs from near the root 

 of this diverticulum ; the ovarian sac, the receptaculum ovorum and the oviduct are 

 quite as in other species. Close to the external orifice of the spermathecal sac are 

 two smaller diverticula. one on each side. 



