i[§g s. GOTO. 



These unite with eacli otlier at the level of tlie front end of the 

 posterior S-shaped portion of the ovary, and the single yolk-duct opens 

 into the oviduct at a little distance from the beginning of the ootyp. 

 The genito-iiitcstinal canal opens into the oviduct about midway between 

 the origin of the latter and the beginning of the ootyp. The vitellaria 

 of the two sides are entirely distinct both in front and behind ; 

 they end anteriorly near the point of bifurcation of the alimentary 

 canal, and posteriorly with the body proper, not extending into the 

 caudal disc, but leaving the posterior portion of the intestinal trunks 

 naked. Testes occupying a little less than one-fifth the whole length 

 of the body, posterior to the ovary ; of rather small size, about 40 

 in number. The two trimks of the intestine sending out only a few 

 short branches towards the median side ; the left \Qg Linger than the 

 rio-ht, and both extendino; for a certain distance into the caudal disc. 

 This occupies about 3 the whole length of the body. Posterior suckers 

 about 29 on each side ; breadth 0.068-0.128 mm. 



Habitat — Gill of Sehastes sp. sp. (Jap. Ma-zoi and Nagara-zoi). 



Localitij — Hakodate. 



Da^e— August 1890. 



3. Microcotijlc elegans, n. sp. 



(PI. I, fig. 4; Pl.Y, fig. 2.) 

 Bodij about 4 mm. long, slender, symmetrical. Anterior sucker 

 with a septum. Common genital opening a little in front of 

 the beginning of the intestinal trurds:s; atrial spines conical, about 

 0.005 mm. in length; a few spines being also present on the posterior 

 wall. Orarg in the anterior half of the bod}^, its hinder end being 

 nearly at the middle of the whole lengtli. Its anterior half is inter- 

 mediate in form between the corresponding portions of M. caulata and 

 M, sehastis; the posterior half is S-shaped, and the terminal portion is 



