STUDIES OX THE ECTOPARASITIC TREMATODES OF JAPAN. 947 



about midway on its wliole 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. ]'as 

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

 the loop whicli it f(3rms at this level is placed perfectly transversely 

 to the len^-th of the b<3dv, Avith the closed end directed as usual 

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

 makinc numerous convolutions on the wav, 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 

 leno'th : the c:dibre of the vas deferens Ijeino- very small in the latter 

 part of its course. 



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

 its own. 



Hahitat — Gill of Xiphias fjladiiis ('Tap. ]\Iekajiki). 



Localitij — Misaki. 



Drtf6'— August 1891. 



This species is evidently very closely related to T. coccineum, Avith 

 whicli 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 difi:erences between the two species if Taschen - 

 berg's figures'^ are perfectly accurate. lu 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 m;u'gins of the body are in 

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

 the body, Avhereas in T. coccineum the rows of 1)oth sides are, accord- 



1). Taschenberg — Beiträge etc. 



