206 ^- GOTO. 



of the accessory bulb 0.032 mm. Ooanj long, U-shaped, with the 

 open end directed forwards, and with the two arms of the U closely 

 apposed to each other ; the end containing the young ova once more 

 bent on itself ; the larger arm situated on the left side of the smaller, 

 and occupying nearly the median line of the body. Vitelhria of 

 the two sides nearly distinct both in front and behind. Relative 

 disposition of the genital ducts same as in 0. major. Testes more 

 numerous than in 0. major '; the anterior ones extending as far an- 

 teriorly as the front end of the ovary, and arranged in a single row 

 on its left side ; the posterior ones extending about two-thirds the 

 distance between the posterior end of the ovary and the foremost 

 pair of suckers. 



Habitat — Gill of Scomber colias (Jap, Saba). 



Locality — Hagi and Misaki. 



Da^e— August 1889 (Hagi), Dec. 1889 (Mis.). 



I believe there is no doubt that ths species above described are 

 new, although they inhabit the same host as 0. scombri (Kuhi). I 

 at first suspected that the two species might have been confounded 

 with each other and described as a single species by European 

 writers, the contradictory statements of v. Beneden and Hesse '^ on 

 the one hand and St.-Remy on the other as to the number of the 

 l^enis spines of 0, scombri seeming in some degree to favour such a view. 

 But the hooks at the posterior end of the body of both the species 

 here described are entirely different in form from those of 0. scombri, 



iadmdual, that represented by fig. 12, I found the diameter of the central bulb to be only 

 0.035 mm. 



1). P. J. \. Beneden and Hesse state them as being ten in number (Eecherclies sur les 

 Bdellodes et les Trematodes marius, p. 97), while accordiog to St.-Eemy they are twelve 

 (Synopsis des Trematodes monogeneses, p. 32). 



