STUDIES ON THE ECTOPARASITIC TREMA.TODES OF JAPAN. 231 



ending with a slight lateral expansion. Anterior end with a large, 

 not very deep notch. With four pairs of stickij (jlamls on each side of 

 the notch. Sucker circular, sub-basil ar, with a short stalk, with a 

 diameter equal to about one-third the length of the body proper, 

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

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

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

 rying numerous minute cMlinous bodies on their free surface. At the 

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

 a small cup-shaped hollow area. Hooks large, strongly recurved at the 

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

 not taken into account). Mo^ith large, at a short distance from the 

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

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

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

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

 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 fjenital 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 0.18 mm. long. Ovarij situated a little in front of the 

 middle of the whole body, long, large, 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 oviiluct proceeds from its origin at first 

 forwards and towards the left, and after receiving the 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 



