STUDIES ON THE ECTOPAEASITIC TREMATODES OF JAPAN. 247 



about midway on its whole course, and finally opening into the yolk- 

 reservoir. Testes small, numerous, confined to the median region 

 enclosed by the intestinal trunks, mostly behind the ovary. Vas 

 deferens taking the usual course up to the anterior end of the ovary ; 

 the loop which it forms at this level is placed perfectly transversely 

 to the length of the body, with the closed end directed as usual 

 towards the right ; after this the vas deferens proceeds forwards, 

 making numerous convolutions on the way, and reaching the 

 front end of the ootyp turns backwards, and enters the penis at a 

 short distance from its base, and describing some convolutions 

 within it finally opens into its cavity about midway ifs whole 

 length ; the calibre of the vas deferens being very small in the latter 

 part of its course. 



Like T. sinuatum this species has a light flesh-red colour of 

 its own. 



Habitat — Gill of Xiphias gladius (Jap. Meknjiki). 



Locality — Misaki. 



Dflte— August 1891. 



This species is evidently very closely related to T. coccineiim, with 

 which I have at first suspected it to be identical. And even now I 

 find myself unable to give up this suspicion, although there are some 

 small but positive differences between the two species if Taschen- 

 berg's figures'^ are perfectly accurate. In the first place the form of 

 the hooks is different, being in T. coccineum simply obliquely hollowed 

 out at the two ends ; and in the second place the transverse rows of 

 minute chitinous bodies on the lateral margins of the body are in 

 T. rotundum wholly absent on the concavity at the posterior end of 

 the body, whereas in T. coccineum the rows of both sides are, accord- 



1). Tasohenberg— Beitriige etc. 



