608 



OLIGOCHAETA 



Fig. 49. 



Genus POLYTOREUTUS, MICHAELSEN. 



DEFINITION. Setae paired, those of ventral pairs further apart than those of dorsal. 

 Clitellum complete, XIII-XVIII. Male pore on XVII/XVIII. Calciferous 

 glands in XIII, ventral pouches in IX, X, XI. On XIX aperture of sperma- 

 thecal sac, which is large and complicated, on XVIIJ/XIX. Ovaries enclosed 

 by an extension forwards of the spermathecal sac. No penial setae. 

 The genus is remarkable in the family for the fact that the spermathecal pore is 



placed behind the male pore ; in all the other genera it lies in front of the male pore. 



,. o The sac into which the aper- 



ture of segment xix opens is 

 unusually complicated ; it is 

 evidently a coelomic pouch as in 

 other Eudrilids. Anteriorly the 

 ovaries are each enclosed in a 

 small sac ; this is appended to 

 the septum between segments 

 xii/xiii ; this ovarian sac com- 

 municates by a narrow duct with 

 the spermathecal sac; the sper- 

 mathecal sac shows traces of 

 being double. In P. coeruleus, 

 P.violoMeus, P. kilindinensis, and 

 P. elongatus, the two tubes fuse 

 altogether, but in P. magilensis 

 (woodcut 50, fig. B) they remain 

 separate, for the most part being 

 connected by transverse tubes of 

 smaller calibre forming a ladder- 

 like arrangement. In P. silvestris 

 and its immediate allies the two 

 sacs are separate posteriorly only. 

 Near to the external opening 

 in P. coeruleus four long diver- 



ticula arise from the spermathecal sac ; the two posterior of these are the longest ; 



in P. niagilensis these two posterior diverticula after a very short course unite to 



form one stout tube ; in P. violaceus there are a series of lateral diverticula, a pair 



GENERATIVE ORGANS 

 OF POLYTOBEUTUS 

 MAGILENSIS. 



i, 7. Sperm-sacs. 2. Sperm- 

 ducts. 3. Calciferons glands. 

 4. Oviducts. 5. Spermiducal 

 glands. 6. Spermathecal 

 sac. 



FEMALE GENERATIVE ORGANS 

 OF THE SAME MORE HIGHLY 

 MAGNIFIED. 



Fig. A. i. Duct leading from egg-sac (5) 

 to spermathecal sac (3). 2. Ovarian sac. 

 4. Oviduct. 



Fig. B. i egg-sac. 2. sperm-duct. 3. 

 Bursa copulatrix. 4. Spermiducal 

 gland. 5, 6. Spermathecal sac. 9 

 External opening of same. 



