W. Nicoll 
3G9 
The parasite is an elongated, somewhat flattened worm, with oval 
outline and pointed ends. It has a distinctly yellow colour and the 
cuticle is smooth and unarmed. 
The specimens vary in length from T35 to T65 mm. with a maximum 
breadth of 0-55-0-65 mm. which occurs about the middle of the body 
or a little behind it. The oval sucker measures 0-13-0-17 mm. and the 
ventral 0-19-0-21 mm., the latter being situated at a distance of 0-55- 
0-65 mm. from the anterior end. Both suckers are globular. 
There is a distinct prepharynx in most specimens and a large pharynx 
measuring about 0-08 x 0-065 mm. The oeso])hagus is a little shorter 
than the pharynx, while the intestinal diverticula have a somewhat 
irregular course and terminate a short distance from the posterior end 
of the body. 
The excretory vesicle is Y-shaped and consists of a long median 
stem which winds forwards between the testes, immediately in front of 
which it bifurcates into two short limbs, which do not reach the level 
of the ovary. 
The median genital aperture is situated over the intestinal bifurca¬ 
tion. The cirrus-pouch is a comparatively large and conspicuous fusiform 
structure, extending well beyond the middle of the ventral sucker on 
the right side and measuring about 0-5 mm. in length. It contains a 
bipartite vesicula seminahs, the proximal part of which is the larger, 
an exceedingly long straight pars prostatica and a short ductus. The 
pouch is filled with a large number of prostatic cells. 
The testes lie decidedly obliquely in the posterior half of the body, 
the anterior testis being on the left. They are separated from each other 
by a small space through which the excretory vesicle passes. The out¬ 
line of the testes is rounded oval or somewhat cordate and their average 
diameter is about 0-15 mm. The post-testicular space measures about 
0-33 mm. and the anterior testis is separated from the ventral sucker 
by a distance of 0-13 mm. 
The ovary lies on the right side immediately behind the ventral 
sucker, which it overlaps, and the cirrus-pouch. It also overlaps the 
right intestinal diverticulum to a slight extent. It is a large transversely 
oval body, measuring 0-15 x 0-21 mm. Adjoining it there is a large 
oval or pear-shaped receptaculum seminis, of variable size and position. 
It usually lies somewhere in the space between the ovary and testes, but 
not infrequently it is pushed forward nearly to the ventral sucker and it 
may be overlapped to a considerable extent by the ovary. 
