30 
the pharynx to the naked eye (fig. 14 and 15). They run down 
towards the intestine as far as the pharynx reaches and are merely 
interrupted in the median line by a short, transverse slit r. This 
slit opens out into a duct which is continued for a short distance 
in the muscular wall of the pharynx; it is coated by the same 
epithelium as the latter and finally leads into the very short me- 
dian cavity in which, on a muscular prominence representing the 
tongue a chitinous structure is again superposed upon the epithelium 
forming an unmistakable radula.. A radula has hitherto not been 
found in Neomenia, nor can I find a trace of it in the specimens I 
examined. In Chaetoderma v.GRAFF(Dd)and Hansen (7) have described 
the simple, tooth-Iike, chitinous body situated in a coecum of. the 
pharynx and no doubt directly homolvgous with a true radula. 
The presence of a radula in Proneomenia is thus of much impor- 
tance in so far as it definitely brings both this genus and its closest 
ally Neomenia amongst the Mollusks. 
As to the exact shape of the radula I hold it to be preferable 
to postpone a definite judgment till it has been possible to 
prepare one out of a freshly caught animal, according to the well- 
known method. For myself I felt no liberty to dispose of my two 
specimens in any other way than by making series of sections that 
could be indefinitely preserred. Under these eircumstances however 
a reconstruction out of the sections of the exact shape and dimen- 
sions of the different parts that compose the radula, is rather a 
dangerous proceeding and can never answer the purpose entirely. 
For that reason I will restrict myself for further reference to the 
three figures of sections through this organ, given in fig.’s 18—21. 
In one of them (fig. 19) a surface view of a portion of the radula 
is obtained, in the other (fig. 21, a few sections further) it is tan- 
gentially, in’ the third (fig. 20) transversely cut. The two latter 
sections show the epithelium very clearly on which the radula 
rests and at the same time they bring the convietion that also in 
Proneomenia KöLLıker’s opinion (15) about the mode of formation of 
the radula, which was combated by SEmPEr (28) and accepted by Kr- 
FERSTEIN (14) is correct. It is here evident that a basal portion b 
