STUDIES OX THE ECTOPAEASITIC TREMATODES OE JAPAN. 125 



wtirds, but sometimes makes more or less windings (PL II, fig. 5). 

 In M. fusiformis (PI. II, fig. 3) the vagina is but slightly enlarged, 

 but in BL tnmcata it assumes the shape of a goblet with its short neck 

 directed towards the front end of the body (PL II, fig. 1). In the 

 latter species it communicates by an exceedingly short, jjaired canal 

 with either of the paired yolk-ducts; while in most other species the 

 single vaginal canal proceeds backward for a greater or less distance 

 along the median line of the body, and then divides right and left 

 into two branches, the paired vaginal canals, which finally open each 

 into the paired yolk-duct of the corresponding side, just as in Oncho- 

 cotyle. In M. sciaenae the vagina immediately divides into two canals, 

 which, after proceeding backwards for a short distance, unite with 

 each other in the median line of the body between the vas deferens on 

 the dorsal and the uterus on the ventral side, then again separate from 

 each other, and proceed backwards for a short distance, and finally 

 open into the paired yolk-ducts (PL II, fig. 6). In Axine helerocerca 

 also, the vagina divides immediately into the paired canals; but in 

 this species these remain separate throughout their Avhole lengths, and 

 proceeding backwards just on the inner' side of the main trunks of the 

 intestine, finally become continuous with the yolk-ducts '^ (PL Ml, 

 fig. 1). There is in this species another opening a little beliind the 

 vagina (PL VIII, fig. 3, x), which leads into a blind cavity, the 

 internal surface of which is armed with low, conical spines like those 

 of the vagina; but although I have directed special attention to the 

 point I have not been able to observe any connection with the genital 

 organs, and am perfectly at a loss what function to attribute to it. 

 In Axine aberrans the vaginal canal is single throughout its extent, 

 and opens into the fore end of the unpaired yolk-ducts. In Axine 



1). The boundary between the Paginal canal and the yolk-duct is marked in the figure 

 with an asterisk. ' ' 



