NO. 2263. ifEW AFRICAN EARTHWORMS— SMITH AND GREEN. 15& 



(branches), and then are abruptly enlarged and continue as large, 

 more or less irregular bodies, as far as somite 36. Due to the 

 displacement of the calciferous glands and the pushing backwards 

 of the septa, the place of enlargement of the sperm sacs is really 

 about opposite somite 16, as indicated by external metamerism. Each 

 sac has a more or less definite lumen which is accompanied by a 

 branch of the vascular system, at least as far as 23, which is as far 

 as the sections extend. 



The prostate glands are each about 10 mm. long and slightly less 

 than 1 mm, in diameter. Each is so bent and folded, that it is in- 

 cluded between the septa of 18, although it crowds these outward so 

 as to include most of somites 16-18, as indicated by external met- 

 amerism. Near its outlet each gland has a small diverticulum of 

 about 0.5 mm. in length and height, which receives the corresponding 

 sperm duct. The duct of each prostate is quite short, and opens 

 separately into the dorsal part of the cavity of the muscular bursa, 

 which is located medially on the ventral floor of 17, and opens to the 

 exterior slightly anterior to the middle of that somite. The bursa is 

 in height about one-fourth of the diameter of the worm and its 

 lumen is much folded, and presumably during copulation the organ 

 is everted and forms a penis. 



The female reproductive organs, in general structure and relations, 

 resemble those of other members of the genus. These relations are 

 indicated to some extent in figure 12 but shown in greater detail in 

 figures 16 and 18 in the species description next following. 



Although the female reproductive organs of Polytoreutus are more 

 or less similar to those of certain other African genera, to one 

 familiar only with the earthworms of North America, they present 

 somewhat anomalous conditions. 



Instead of paired spermathecae with pores anterior to the oviducal 

 pores, we have normally in Polytoreutus a more or less fused condi- 

 tion of what was, perhaps, originally a pair of sacs, and also have a 

 single median ventral pore in 18/19 or on 19. The ovarian cells are 

 more commonly found in the ovisacs which are closely related to 

 septum 13/14. There seems to be evidence in support of the view 

 that in some species, at least, these cells are at first related to septum 

 12/13 and are subsequently shifted to the ovisacs. The oviducts 

 open to the exterior in a normal fashion, but internally each one 

 communicates with, the corresponding ovisac and also with the an- 

 terior part of the spermathecal apparatus. A further peculiarity of 

 the oviducts of a number of species, is the presence of one or more 

 chambered diverticula, crowded with matured sperm cells and in- 

 cluded in a thick-walled enlargement of each oviduct, called by 

 Michaelsen, the eitrichterblase. 



