ox DIPLOZOON NIPPON ICUM, N. SP. 173 



eel to do in some other Trematodes. Between these fibres is found 

 a muss of connective tissue with conspicuous nuclei. These nuclei 

 are doubtless the remnants of the cells that produced the muscular 

 fibres and the connective tissue of the pharynx. Strong dorso- ventral 

 muscular bundles (Fig. 11, dvm) are closely applied to the wall of 

 tlie |;harynx, and no doubt assist in its action. The total thickness 

 of the pharyngeal wall, the internal membrane inclusive, is about 

 0.02 mm. 



The cavity of the pharynx leads directly into the oesophagus, a 

 simjjle, slender, tubular portion, which is directly continued into the 

 meilian trunk of the intestine. This median trunk sends out in the 

 anterior half of the body, right and left, lateral branches, which rami- 

 fy dichotomously once or twice. Some of these lateral branches are 

 distinctly paired, but I have also observed others which are as dis- 

 tinctly unpaired. Posterior to the place of crossing of the two in- 

 dividuals the lateral branches are absent. Here the median trunk 

 divides into two, one of which retains nearly the median position, 

 while the other proceeds more laterally towards the ovary. Posterior 

 to the testis these two branches unite, and thenceforth the intestine 

 proceeds towards the suckers as a simple unbranched tube, and ends 

 between and a little anterior to the first pair of suckers, where it 

 generally presents a rounded enlargement. '• A l'endroit ou les deux 

 corps s'unissent, les coecums digestifs semblent atrophiés, mais en 

 dessous de l'appareil générateur, dans le bout postérieur du corps, 

 chacpie tube présente de nouveau ses ramifications régulières et com- 

 plètement séparées, comme dans la partie antérieure," says v. Bene- 

 den,^* and I can confirm his observation with my own on the Euro- 

 pean species ; but in 7iipponicum I have found this part of the intestine 

 always sim[)le. The wall of the intestine is destitute of an epitheliinn 



1) P. J. V. Beneden— 1, c. p. 40. 



