STUDIES OX THE ECTOPARASITIC TEEMATODES OF JAPAN. 249 



the pharynx, at about the plane of the middle of the whole length of 

 the latter. Penis short and thick, Omnj at the hinder end of the an- 

 terior third of the body proper, ovoid, being longer from right to 

 left, not lobed. Ociduct arising at the front end of the ovary in the 

 median line, thence proceeding forwards with a slight winding or two, 

 and continued into the ootyp. Uterus not very long, opening into 

 the genital atrium near its bottom. Vitellariwn mainly confined to the 

 lateral regions and the anterior lobe of the body, and only accompany- 

 ing the intestinal branches into the median region. Faired yolk-ducts, 

 yolk-reservoir, and impaired yolk-duct as in the preceding species. Testes 

 small, globular, numerous, confined to the median region between the 

 intestinal trunks. Vaginal opening a little behind the common genital 

 opening ; vaginal canal ]5roceeding as usual backwards and towards the 

 median line, and after forming a capacious, globular receptaculum 

 seininis, opening finally into the yolk-reservoir. 



Hahitat — Gill of an undetermined species of fish the Japanese 

 name of which is Hazara. 



Loca lity — Misaki. 



i'rtfe— August 1891. 



5. Tristomum Nozaicae,''^ n. sp. 

 (PL XXV, figs. 1-3.) 

 Body elongated-ovate, about 12 mm. long by 7 mm. broad, with 

 the truncate anterior border perfectly straight, with the anterior 

 lobe of the body sep.arated from the lateral borders only by a 

 shallow constriction ; lateral margin entire, destitute of any chitin- 

 ous corpuscle ; with a large notch at the posterior end of the body 



1). Dedicated to Shunjiro Xozawa, Nogakushi, Naturalist to the Fisheries Bureau 

 of the Hokkaido Cho, to whom as well as to Kazutakalto Esqr., the then Director of the 

 Fisheries Bureau, are due my best thanks for giving me numerous facilities for collection 

 during my stay in Hakodate. 



