ZooL.— Vol. II.] RISEN— OLIGOCHMTA. 237 



The geyiital zone, on account of the absence of a clitel- 

 lum, is less developed than in fully matured specimens. The 

 two lunate ridges covering the three somites XVII to XIX 

 are of even thickness throughout their length, and so curved 

 that they enclose between them a zone oval in the center. 

 The specimens not being in the very best condition, it was 

 impossible to observe any of the exterior pores. 



The sctcR are strictly paired and all ventral. Their tips 

 are slightly scalloped. The absence of penial setae brings 

 this species into close relation with Dichogaster Damonis, 

 which species it also resembles on account of its accessory 

 prostates. 



The sfenn-ducts are straight, without the horseshoe-like 

 bend found in D. Crawi. The two sperm-ducts are sepa- 

 rate until they reach somite XVII, where they fuse into one 

 just before entering the male pore, which is intersegmental 

 and not equatorial. 



The absence of sferm-sacs may be due to the immature 

 state of the specimens. 



The sperm-funnels lie immediately behind the testes in X 

 and XI. In line with the testes, but in somite XII, is found 

 a pair of structures resembling ovaries. They are some- 

 what smaller than the regular ovaries in XIII and less 

 divided than the testes. These structures are probably 

 accidental. 



The prostates have the normal structure. There is a 

 long muscular duct and a thicker glandular upper part. 

 The latter, which is confined to one somite, contains two 

 layers of cells, the inner of which is very minute. 



There are no ovisacs developed. The spermathecse are 

 large and sac-like, pointing forward. There are several 

 small wart-like diverticles pointing forward and penetrating 

 the anterior septum, the diverticles thus being on one side 

 of the septum, while the main sac is on the other. The 

 pores are in the intersegmental grooves. 



