234 Transactions of the Royal Society of South Africa. 
central lumen, with granular protoplasm and a large basally situated 
nucleus. 
{h) As in the case of the spermathecal ducts in Astacopsidrilus, &c., 
there is a well-developed circular musculature. 
(c) The outermost layer, which is greatly exaggerated in the figure, 
consists of a flattened and indistinct coelomic epithelium. 
The duct on approaching the spermatheca becomes confluent at first 
with a horn given off from the antero-ventral portion of the spermathecal 
chamber. It pushes itself into the ventral side of this horn as represented 
in the figures so that it and the crescentic horn become encased in a 
common circular musculature. Eventually the duct becomes free in the 
cavity of the horn, but is now devoid of a musculature, consisting solely 
of cuneate granular cells. It ceases at the line of junction between the 
horn and main part of the spermatheca. 
The horn thus envelops the duct as a sheath. 
The wall of the horn consists of a lining layer of epithelial cells which 
are loosely arranged, pyriform or lobose, and a distinct outer circular 
musculature which is confluent with that of the spermathecal duct. 
The epithelium of large lobose cells is continued over the interior of 
the anterior and ventral wall of the main part of the spermatheca. 
These cells are very large at the commencement of the spermatheca. 
This strong epithelium withers away posteriorly, especially along the 
dorsal wall of the chamber, to such an extent that with a fairly high 
objective it is difiicult to decipher whether this very thin dorsal wall is 
constituted by a very much flattened epithelium or by a basement 
membrane from which the epithelial cells found in the anterior and 
ventral regions have dropped away. This latter idea is suggested by the 
loose nature of the large lobate cells in the anterior region of the sac and 
in the horn of the same, and would seem to be the most satisfactory way 
of explaining the histological differences between the different regions of 
the spermatheca, and between the spermatheca in part in Gondwanaedrilus 
and that of other Phreodrilidae such as Phreodrilus and Astacopsi- 
drilus. 
The circular musculature found external to the epithelium of the 
spermathecal duct and spermathecal horn extends for a very short 
distance external to the epithelium of the anterior part of the chamber, 
but soon dies out. 
In this region also both dorsally and ventrally there are the remains 
of a loose epithelium, represented by pear-shaped cells, isolated, and much 
smaller than the lining epithelial cells. 
The spermiducal gland is a sigmoid structure, being made up by an 
axial portion directed antero-dorsally and postero-ventrally, an anterior 
part running ventrally from the anterior extremity of this, and an 
