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honeycomb-like arrangement. In the honeycomb-cellulæ only the 
glandular epithelium forms the thick covering. It is evident that 
this type is simpler than the Stylochus-typQ. 
As primitive condition I regard it, where the epithelium carries all 
of the intracapsular granular giands, as in Crytophallus, etc. The 
separation of an extremely low epithelium, having lost all the giand 
cell bodies and thus only pierced by their outlets and the forma¬ 
tion of a subepithelial, intracapsular secretion layer, as in Disco- 
stylochus and Siylochus, musi signify a specialization. 
Thus, containing a very large amount of secretion, the sub¬ 
epithelial layer allows an increase of the capacity of the vesicle. 
We meet with this feature in the vesicles which have attained a 
considerable size. 
A more simple type of vesicula granulorum than that of Lepto- 
stylochus characterizes some other members of the family. In the 
elongated, narrow vesicle of Neostylochiis, the epithelium is unfolded 
and bounded by the muscularis. Having the singular shape of a 
sinuous tube, the exceedingly prolonged vesicle of Limnostylochus 
belongs probably to this kind of vesicles; at least there is nothing 
else suggested by the descriptions and figures. In passing it might 
be mentioned that, in agreement with Neostylochus, the fresh-water 
Polyclad L. borneensis possesses a penis stylet, while the tvo species 
described by Kaburaki (1918) have an unarmed penis. To the 
Neostylochus-typQ I count also the prostatic vesicles of Bergendalia 
diversa. I must here rely on a schematic diagram presented by 
Yeri and Kaburaki, since no details are given in the description. 
The horizontal position with the blind end directed forwards, the 
displacement away from the penis, and the oval shape agree with the type, 
and the low lining in the interior represents probably nothing but 
an epithelium. In Bergendalia diversa the prostatic vesicle has been 
much reduced. Situated above the penis it has a circular outline 
and connects with the penis canal by means of a long efferent 
duet. Laidlaw says that „its wall consists of a very thin layer of 
circular muscle-fibres, lined with a cubical epithelium”, having the 
appearance of an exhausted secretory tissue. The genus Bergendalia 
presents the interesting feature of a duplicate male organ situated 
before or behind the ordinary one, but lacking connection with 
the seminiferous system. Its prostatic vesicle shows similarity to that 
of the ordinary male organ. 
