142 DR. W. NICOLL ON TREMATODE 
highly-convoluted vesicula seminalis with a short prostate and 
ductus. The testes lie alongside one another, almost at the 
posterior end of the body. ‘They are slightly asymmetrical, the 
left being a little in advance of the right, and they are separated 
by a narrow fold of the uterus. They are elongated oval in 
outline and measure *35 x22 mm. 
A little in front of the testes les a small round ovary, some- 
what on the right side of the middle line. The shell-gland 
complex is entirely obscured by the uterus. The yolk-glands are 
of restricted extent, being confined to the extreme edges of the 
body and extending only from the ovary to some distance behind 
the ventral sucker. The uterus fills up the whole of the middle 
of the body and sends a small loop down between the testes. The 
eges are thin-walled and very transparent, and the majority of 
them contain a fully developed miracidium, the K-shaped eye- 
spots of which are very conspicuous. The eggs measure ‘095 x 
"056 mm. 
This form evidently belongs to the family Lepodermatide, but 
it is somewhat aberrant. Its most distinctive features are the 
unusual position of the genital glands and the precocious develop- 
ment of the miracidia, together with the large size of the eggs. 
3. OPISTHOGENES INrTERROGATIVUS, gen. et sp.n. (PI. II. fig. 4.) 
Five specimens of this parasite were obtained from the intestine 
of Schott’s Snake (Philodryas schotti). In length they vary from 
4-5 mm. to 6°2 mm. (pressed specimens); the average is 5°-4 mm. 
The greatest breadth across the ventral sucker is 17 mm. The 
outline is almost fusiform, the posterior half being more attenuated 
than the anterior. 
Both suckers are nearly globular, the oral measuring ‘64 mm. 
and the ventral ‘56 mm. In both cases the longitudinal diameter 
is usually slightly greater than the transverse. The ventral 
sucker is situated 1:74 mm. from the anterior end. There isa 
short prepharynx followed by a pharynx measuring °21 x-2 mm. 
The cesophagus is slightly longer than the pharynx, °27 mm. 
The intestinal diverticula terminate some distance (about *6 mm.) 
from the posterior end of the body, but their ends are obscured 
by the dense mass of the uterus. 
The excretory vesicle is long and wide. The median stem runs 
forward to near the ovary before dividing into the two short 
lateral branches. ‘The vesicle, as well as the main collecting 
tubules, are clearly mapped out owing to the pigmented nature 
of their contents. A large number of fine branches are given 
off from the vesicle, and these form an anastomosing network 
througbout the whole body. 
The cirrus-pouch has the shape of an interrogation mark, 
curving over the left posterior quadrant of the ventral sucker. 
Its proximal end lies a short distance behind the sucker, while 
the male genital aperture is 1 mm. behind the sucker and a little 
to the left of the middle line. The female aperture is separated 
