144 DR. W. NICOLL ON TREMATODE 
In shape it is elongated oval with somewhat pointed ends and 
almost parallel sides. The length is about 1:3 mm. and the 
greatest breadth -46 mm. ‘The cuticle is beset for at least three- 
quarters of the length of the body with minute spines. The oral 
sucker is subterminal and has a diameter of 17 mm. The round 
ventral sucker is much smaller, measuring only -10 mm,, and 
it is situated at a distance of -55 mm. from the anterior end of 
the body. 
There is a short prepharynx, a pharynx measuring ‘06 x '08 mm,, 
and a long cesophagus, twice the length of the pharynx. The 
intestinal diverticula are rather wide, and do not extend more 
than halfway between the ventral sucker and the posterior end 
of the body, The excretory vesicle is dilated and the median 
stem divides a short distance behind the ovary. The paired 
limbs only extend to the ventral sucker. 
The genital aperture lies a short distance behind the intestinal 
bifurcation. The cirrus-pouch is short and plump, reaching only 
a short distance behind the anterior border of the ventral sucker. 
It contains a highly convoluted vesicula seminalis, a short pars 
prostatica, and a short ductus ejaculatorius. The testes lie at the 
level of the end of the intestines. They are tandem or slightly 
oblique, and almost contiguous. They are of very irregular shape, 
and are always broader than long, Their dimensions are about 
"06 x13 mm. The post-testicular space is almost exactly one- 
quarter of the body-length. 
The ovary is contiguous with the ventral sucker on its right 
posterior border. It also touches the right intestinal diverticulum, 
Tts size is ‘08-06 mm, The yolk-glands are extremely scattered 
and imperfectly formed. They consist of small, rather isolated 
follicles extending along the sides of the body from the middle of 
the esophagus to the middle of the post-testicular space. In the 
latter they extend inwards but do not meet in the middle line. 
They overlap the intestinal diverticula only to a very slight 
extent. The uterus is confined between the testes and the ventral 
sucker, and does not overlap the intestinal diverticula, It con- 
tains about two dozen eggs, measuring ‘042 x -021 mm. 
It does not appear likely that this can be the young stage of 
any of the already known species of Opisthioglyphe, for it is 
differentiated from O. rane by the length of the intestinal 
diverticula and the ratio of the suckers. The configuration of the 
excretory vesicle is also different. From O. hystrix it differs in 
the position of the ventral sucker, the length of the intestinal 
diverticula and of the cirrus-pouch, and the extent of the yolk- 
glands. It also differs in several important particulars from the 
more recently described O. locellus Kossack. I am unable to 
compare it with O. siredonis, as Poirier’s paper is not available. 
5, SYYPHLODORA PERSIMILIS, sp.n. (PI. IL. fig. 5.) 
About thirty specimens of this parasite were removed from 
the ureters of an Indian River-Snake (Zropidonotus piscator) 
