84 
Fig. 3. L.ongitudinal section through the hinder part of the pharynx. To the 
left above the antrum masculinum the stylet of the penis is visible. 
An accidental fissure, f, on this section, between the basement membrane 
and muscle wall of the body. It continues into the short unpaired 
anterior branch of the intestine. 
Fig. 4. Longitudinal section through the sexual apparatus. The upper part of 
the vagina, i. e. the part above the shell sac (ss), bends somewhat 
sidewards and consequently does not appear in this section. Only 
one of the two accessory vesicles of the male apparatus is present 
in the section. In the penis the penis canal is visible. Above the 
short anterior gut branch is an accidental fissure. 
Emprosthopharynx opisthoporus Bock 1913, 
Figs. 5 —7. 
Fig. 5. Part of a longitudinal section demonstrating the superficial location 
of the tentacular eyes. It ought further to be observed that the muscle 
layers of the body wall disappear below the very insignificant pro- 
minence corresponding to a rudimentary tentacle. 
Fig. 6. Lateral part of the body showing the nerve-net, Animal made trans¬ 
parent in cedar-wood oil. 
Fig. 7. One of the specimens in alcohol. 
2().V.25. 
