STUDIES OX THE EOTOPARASITIC TREMATODES OF JAPAN. 193 



in front, but apparently continuous behind. Testes occupying a 

 comparatively small area about one-sixth the M'hole length of the 

 body, posterior to tlie ovary; of moderate size and comparatively 

 few in number (about 15). Xo lateral branches on the median side 

 of the intestinal trnulis; tlie left trunk longer than the right. Cauda} 

 disc continuous with the rest of the body, and the sucl'ers occupying 

 nearly one-half the whole lateral borders of the body; suckers 80-33 

 or more on each side; breadth O.O-iG-0.065 mm. 



Habitat — Gill of Ceiitwnotus ruhdosus (Jap. Gimpo). 



Localitij — ]\Iitsugahama. 



Dr^f*:'— August 1889. 



7. JSIicrocotijJe clnn\ n. sp. 



(PI. II, figs, i Sc5: PI. Ill, fig. 5 ; PI. Y, fig. 4.) 

 Bjdii about 4.2 mm. long, symmetrical, slender in the anterior 

 portion where the vitellarium is absent, but the remaining portion 

 much broader, rounded at both ends. Common ijenital opening 

 situated a little in front of the liinder end of the oesophagus; genital 

 atrium with a hemispherical, cup-shaped organ on the dorsal side, the 

 inner surface of which is covered with spines similar in shape to those 

 of i)/. r<:'?/6'»/((/<Y, and about 0.015 mm. long. The front half of the 

 ovarii follows in its course nearly the three sides of an isosceles triangle 

 whose apex is directed backwards ; and the posterior half is many 

 times folded on itself into a close, irregular spiral. Vaginal opening 

 single, median, and dorsal, nearly lialf as far behind the common 

 genital opening as it is before the front end of the ovary. Tiie 

 vaginal canal divides into two at a point which is about half as far 

 from the vaginal opening as from the anterior end of the ovary, and 

 the two canals, after traversing oidy a short distance, become continu- 

 ous with the paired yollc-ducts. These unite a little in front of the 



