STUDIES OX THE ECTOPAR.VSITIC TREMATODES OF JAPAN. 9 0^l 



ending with :i slight l:iter:il expansion. Anterior eml with u lar^e, 

 not very deep notch. With four priir.s of stich i/ (jhmih on ench side (jf 

 tlie notch. Snclrr circular, snh-hasilar, witli a sliort stalk, with a 

 diameter equal to alxnit one-third the lenii'th of the hodv proper, 

 provided with a marginal memhrane ; every two of the radial spokes 

 lie in a line, and one of the -e pairs coincides with the median line of 

 the body. The marginal membrane as well as the radial spokes car- 

 rying numerous minute cliiliuoiis hoilics on their free surfoce. At the 

 centre of the sucker where the radial spokes all meet together is left 

 a small cup-sliaped hollow area. Hool's large, strongly recurved at the 

 end, and with a sort of conspicuous barb; 0.12 mm. long (curvature 

 not taken into account). Mouth large, at a short distance from the 

 anterior end of the body, with a capacious funnel-slraped cavity. Xo 

 anterior sucker, but with the dorso-ventral musculature around the 

 mouth specially developed and serving as a sucker. Pluinjnx typical- 

 ly egg-shaped, large. Oesophagus exceedingly short. Intestinal trunJis 

 simple, tubular, describing a few windings, and ending just 

 behind the anterior end of the sucker, in the median line, close 

 to each other but separate. Common genital opening about as far 

 behind the posterior end of the pharynx as the total length of the 

 latter ; with a tubular chitinous penis making a single spiral wind- 

 ing, about O.IS mm. long. Oearu situated a little in front of the 

 middle of the whole bod}^, long, l-irge, and globular at its proximal 

 end {i.e. the formative zone) but slender towards its distal end, twice 

 forming a loop, and the more distal loop embracing the intestinal 

 trunk of the right side. The or/J?(6^f proceeds from its origin at first 

 forwards and towards the left, and after receiving tlie yolk-ducts and 

 the vaginal canal, it sharply turns back towards the right, keeping 

 its forward course, and is continued into the ootijp. This with its 

 thick wall is very large and conspicuous, and opens directly into the 



