^Og s. GOTO. 



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

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

 apposed to each otlier ; 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 tlie body. Vitcllaria 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). 



Local itij — Hagi and Misaki. 



D^i/6'— August 1889 (Hagi), Dec. 1889 (Mis.). 



I believe there is no doubt that th3 species above described arc 

 new, although they inhal)it the same host as O. scombri (^Knltii). I 

 at first suspected that the two species niiglit have been confounded 

 with eacli other and described as a single s[)ecies by European 

 writers, the contradictory statements of v. ]]eneden and Hesse'* on 

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

 penis spines of 0. scomhri seeming in some degree to fivour such a view. 

 But the hooks at the ])Osterior end of the body of both the species 

 here described are entirelv different in form from those of (>. scombri. 



iadividual, that reproseuted Ijy fi^^. 12, I found the diameter of the central bull) to be only 

 0.035 mm. 



1). P. J. T. Beneden and Hesse state them as beiur? ten in uumljor (Recherches sur les 

 Bdellodos et les Trematodes marins, p. 97), while according to St.-liemy they are twelve 

 (Synopsis des Trematodes monogénèses, p. 32). 



