OLIGOCHATA OF TROPICAL EASTERN AFRICA. 219 
These cells are in places partly covered by isolated groups of 
cells much smaller than themselves. These cells lie to a great 
extent loose in the cavity of the spermatotheca; only here 
and there are they congregated into little heaps covering the 
epidermic lining of the pouch. Presently the covering of 
peritoneal cells gets to be closer, and coincidently with this 
the cells which they cover diminish in height, though they are 
still clearly separated from each other; indeed, the separation 
is usually marked by a darkly staining but structureless layer, 
which seems to be thrown off by the epidermic cells. The 
peritoneal cells which cover the subjacent epidermis are long 
and filamentous cells, which proliferate freely at their free 
extremity. The whole structure of the spermatothecal sac of 
this species seems, asin the case of Eudriloides Cotterilli, 
which it greatly resembles, to indicate that it is formed out of a 
peritoneal sac into which an epidermic invagination has grown. 
The fact that there seems to be no external pore is very 
remarkable and unintelligible. It is a further point of agree- 
ment with the other species of this genus described in the 
present paper, and also with Stuhlmannia. All the worms 
that I examined were sexually mature, but in no one of them 
were there any bodies of any sort within the spermatothecal 
sac, except the detached cells evidently derived from the lining 
peritoneal epithelium. In no one of them was there any pore 
leading to the exterior. It is, of course, possible that at stated 
seasons there is a pore which is at other times blocked; but 
this is only supposition, and I have no facts which suggest 
any interpretation of the use of these sacs. In front of and 
behind the point where the external aperture of the sper- 
matothece ought to be, were it visible, is a glandular mass 
lying upon the bursa. This mass reaches down on either side, 
thus forming two rings, one anterior and one posterior, nearly 
enclosing the spermatothecal sac. These two ring-shaped 
glands are composed of small nucleated cells, which above the 
spermatotheca are arranged in a continuous mass. As the 
gland comes to lie at the sides of the sac its cells become 
arranged in a series of columns, which anastomose here and 
