STEUCTURE OF TWO NEW GENERA OF EARTHWORMS. 249 



On dissecting a specimen of Hyperiodrilus, the only part 

 of the female reproductive system that could be at first detected 

 (fig. 47) was a longish oval spermatheca lying upon the dorsal 

 wall of the gut, in the 13th segment, and directed backwards. 

 After carefully removing the calciferous glands, to which the 

 spermatheca and neighbouriug part of the reproductive organs 

 are closely attached, the spermatheca was seen to divide into 

 two thick-walled tubes; these (see fig. 1) are placed close to the 

 septum which divides the 13tli from the 12th segment, and 

 which is conspicuous on account of its being the last of the 

 specially thickened septa. The two tubes, asinStuhlmannia, 

 completely encircle the gut, and meet below in the small 

 atrium which opens on to the exterior by the median pore 

 already referred to as existing upon the 13th segment. Each 

 of these two tubes is provided on the outer side (fig. 8) with 

 a small prominence, which looks like a diverticulum of it, and 

 which corresponds to the structure termed by Michaelsen 

 " receptaculum ovorum" in Stuhlmannia; close to this 

 arises on either side the oviduct, which passes straight to its 

 opening on the 14th segment. 



The atrium is not furnished with a second diverticulum 

 corresponding to the " spermatheca " of Stuhlmannia. 

 Fig. 47 represents the parts described as seen on the dissection 

 of the worm. In fig. 8 is a more diagrammatic sketch of the 

 same parts, in order to display their mutual relations, and 

 their position with regard to the oesophagus and the dorsal 

 blood-vessel. 



An investigation by means of longitudinal and transverse 

 sections shows that these structures, which are alone clearly 

 visible on a dissection, and which form a continuous whole 

 easily to be separated and mounted on a slide, do not represent 

 the entire female reproductive system. 



The ovaries are paired structures, lying as usual in the 13th 

 segment ; they are very compact bodies, not frayed out into 

 numerous processes. Instead oflying freely in the cavity 

 of the 13th segment, each ovary is enclosed in a special 

 coelomic sac of a globular form; this sac also includes a 



