18 Nils Hj. Odhner 
feeble muscular dissepiments as seen in the sections. Its epithe- 
lium is secretory all round except in the dorsal median line 
(beneath the septum of the gonads) where there runs a furrow 
lined with ciliated cells and bounded with a string of elevated — 
cells at each side (fig. 12). In the rear end of the body be- | 
neath the pericardium, the ciliated epithelium is extended to the 
whole dorsal wall and in the rectum, which is as usual narrow 
and lacks the diverticula, the epithelium is constituted of ciliated 
cells only. 
In the genital organs mature spermatids as well as ova were 
simultaneously present; the former were secreted along the outer 
walls, the latter on the interior one. The male products are 
formed in folliculi, which, however, do not correspond to those 
of the intestine and are irregular in size; each opens by means 
of a central rupture into the main genital duct. The median 
septum is relatively thick, even and perpendicular, and contains in 
its basal as well as its dorsal part the chief trunks of the dorsal 
blood vessel (fig. 12), and narrow communications between them 
within the septum. No folds rise from the septum, and the ova 
are formed in a single series along each of its sides. The eggs 
develop from single cells and are covered with a thin membrana 
vitellina, thus lacking follicle epithelium. 
The coelomoducts (fig. 2) are composed each of a dorsal or 
proximal and a ventral or distal leg. The former is lined with 
a low ciliated epithelium. In its median part dilated, it forms 
at its foremost end a new sac-like widening to the upper and 
hind portion of which are attached three small vesiculae (fig. 2, 
v.s.). From this sac, which is lined with high ciliated cells, the 
distal portion or shell gland issues. Its walls are smooth and 
consist of elevated vacuolated celis which are deeply dyed with 
haematoxylin and contain large masses of granula which are 
emptied into the lumen of this part of the shell gland. The two 
distal legs widen backward and are joined medially to an unpai- 
red pouch with thick folded walls lined with high cells contai- 
ning a basal nucleus and a vacuole, and for the rest masses of 
granula arranged in rows along the walls; these granula had 
been imbued with red colour by eosin. Between these cells there 
are slender ones with a lengthened nucleus situated more medially. 
This terminal portion opens through a narrow duct into the cloa- 
cal cavity. Beneath its aperture there debouches on each side a 
