J32 S- GOTO. 



ed on the side turned towards the dorsum, so that when the observer 

 looks at the worm with the suckers turned towards liim he has before 

 him the dorsal side of the body, whereas in other species the ventral 

 side would under the same circumstance be turned towards him. I 

 therefore believe that Tas clien berg was misled in his orientation by 

 the abnormal position of the suckers, and this is the more probable 

 because he seems to have had but little recourse to serial sections. 



In Hexacotijk grossa the origin of the genito-intestinal canal from 

 the oviduct is also near the opening of the yolk-duct a little towards 

 the ovary. Proceeding a very short distance forwards it undergoes 

 a rather sudden and somewhat club-shaped enlargement which, since 

 it contains sperm mass in its interior, may well be called recepta- 

 culiun semim's. From its opposite end arises a much convoluted small 

 canal, which proceeds forwards and towards the right side of the 

 body, and finally opens into the intestine (Pi. XIV, fig. 7). In Hexa- 

 cotijlc acuta the genito-intestinal canal opens into the oviduct side by 

 side with the unpaired yolk-duct, and, in most specimens, was soon 

 enlarged into the reccptaculum scminis, so that the latter was connected 

 with the oviduct by an exceedingly short canal. The general form of 

 the seminal receptacle in this species is similar to that of the other 

 species, but its outline is in most cases irregularly wavy, and the 

 whole organ usually assumes such a position that its long axis is 

 directed obliquely to the long axis of the body. The anterior end of 

 the seminal receptacle gives rise to a small canal of variable length, 

 which, proceeding a little forwards when the receptacle is small or a 

 little backwards when it is large, and making some convolutions on 

 the way, finally opens into the intestine (PI. XIV, fig. 4). In both 

 species of Hcxacotijle the seminal receptacle is situated on the ventral 

 side of the ovary. 



From the abo^'e description it will be evident that the rccepiacuhim 



