DESCRIPTIONS OF GENERA AND SPECIES 613 



The spermiducal glands are long and thick with an irregular sacculation towards 

 the blind end. The distal end of each gland is slightly thicker and sharply marked 

 off from the rest ; it narrows, however, before opening into the median bursa. The 

 sperm-sacs are long (28 mm.) and occupy about twenty segments ; they are fused 

 at the distal extremity. The anterior third or rather more of each sac is, as in other 

 species, a slender tube showing no increase of diameter between the septa. 



The last thick septum bounds segment xi posteriorly. The dorsal vessel suddenly 

 diminishes in calibre in the fourteenth segment ; it is double in segments viii, ix and 

 xii, xiii, and possibly some anterior to the eighth. 



(7) Polytoreutus usindjaensis, MICHAELSEN. 



P. usindjaensis, MICHAELSEN, Thierwelt Ost-Afrik., Regenw., p. 14. 



Definition. Length, 200 mm.; number of segments, 199. Clitellum, XIF-XVII. Sperma- 

 thecal sac divides at first into two, each with a large diverticulum, reuniting afterwards. 

 Hab. Usindja, Bukoba, Mtagata, Antranda, E. Africa. 



The fact that the spermathecal sac is double at first distinguishes this species 

 from all those that have been as yet described ; but it agrees in this with the two 

 following. 



(8) Polytoreutus kirimaensis, MICHAELSEN. 

 P. kirimaensis, MICHAELSEN, loc. cit., p. 16. 



Definition. Length, 140 mm. ; number of segments, 236. Clitellum, XIY-XVII. Sperma- 

 thecal sac as in last species. A pair of large muscular sacs open into bursa copulatrix 

 in common with spermiducal glands. Hab. Kirima, Lake Albert Edward, E. Africa. 



This species is in many respects like the last ; the most noteworthy difference 

 being the presence of the large lateral sacs which open in common with the 

 spermiducal glands. These structures, which also occur in the next species, are 

 possibly to be compared with the muscular sac found in Stuhlmannia. The sperm- 

 sacs on the present species extend back as far as the forty-fifth segment; up to the 

 thirty-sixth segment they are thin and delicate. 



(9) Polytoreutus silvestris, MICHAELSEN. 

 P. silvestris, MICHAELSEN, loc. cit., p. 18. 



Definition. Length, 300 mm. ; number of segments, 300. Clitellum, XIII XVII. Sperma- 

 thecal sac as in last species, but diverticula of much greater length, and sac double from 

 the very first. A pair of large muscular sacs open into bursa copulatrix. Hab. 

 Runssoro Forest. 



