39 
walls of the intestine are closely applied against the hermaphrodite 
gland, following its different curvatures (fig. 48, df). In the me- 
dian line a deep longitudinal fold of the intestine always penetrates 
into the texture of this gland and separates the inferior portion into 
its right and left halves. This longitudinal median fold (figs. 47 & 51, if) 
is always very strongly ciliated, as is also the region above the vent- 
ral bloodsinus. In this respect there is again similarity to Neo- 
menia for which v. GRAFF describes a ciliated intestinal furrow both in 
the mediodorsal and medioventral line. Kor£n and DAnIELssEN (16) 
have since expressed the opinion that in Neomenia the whole of 
the intestinal surface is ciliated. Proneomenia would better vorresp- 
ond with v. GrArr’s statements: here too I have vainly sought for 
cilia on the lateral portions of the laminae, whereas on the con- 
trary the curious cells predominate which v. GrAFF first noticed in 
the intestine of Chaetoderma and afterwards again in that of Neo- 
menia. These appear to secrete a slimy substance which , according 
to v. GRAFF is subservient to the digestive function. The secretion 
could be observed in different phases of expulsion in every section. 
Fig. 45 represents some of these cells in which a nucleus is gen- 
erally very distinetly visible. In height and dimensions they cor- 
respond as a rule with the ciliated cells of the dorsal and ventral 
median portions. The globular corpuscles seereted by them often 
partly fill the space between two adjacent laminae. May not these 
secretory cells be regarded as the most primitive form of a not yet 
fully differentiated liver? A separate liver has not as yet been noticed 
in Neomenia; in Chaetoderma Hasen is inclined to regard as such 
a wide coecum of the intestine stretching backwards; in Chiton 
the liver is built more in accordance with the type known for the 
higher Mollusks. v. GRAFF compares the cells above alluded to with 
the „Becherzellen” originally described in other animals by F. E. 
SCHULZE (27). 
It has already been noticed that the spaces behind the intestinal wall 
and enclosed by the duplicatures (fig. 48, sf) which form the transverse 
laminae are generally filled with eireulating fluid. The connective 
tissue is here sparingly distributed, more in the form of threads and 
HUpRrRECHT, Proneomenia sluiteri. ce 
