39 
occupying more than half the height of the body. Thus the post- 
erior continuation of the main gut becomes flattened, its epithelium 
is lower, and there is no bead-like appearance. In this connection 
it might be mentioned that the female apparatus exerts even a 
stronger influence on the intestine, which becomes still more flattened. 
The normal thickness of intestinal epithelium does not return until 
back of the median uterine duet, 
The penis is wide at its base, but diminishes quickly in width 
near its apex. The antrum masculinum is practically filled up by 
the penis (text-fig. 13). This has a caudal direction, and is unarmed, 
extremely muscular, and covered with an epithelium that becomes 
particularly low near the apex. Next to the thin circular muscular 
layer lying underneath the epithelium is a mueh thicker longitudinal 
one, which is followed by bundles of circular and retractor fibres 
in the thin parenchymatous tissue that surrounds the stout muscular 
coat of the two duets that traverse the penis. 
The fe male apparatus; The female copulatory apparatus 
is of special interest through the development of a ductus genito- 
intestinalis. 
The vagina and its course is clearly seen in text-fig. 13. 
It is better developed than in the genus Stylochus. As in this 
