292 
Trematode of Snakes 
The pharynx is contiguous with the oral sucker and measures 
0-15 x 0135 mm. The oesophagus is extremely short and divides 
almost immediately into the diverticula. These pass down along the 
sides of the body but their course is greatly obscured by the uterus. 
Their terminations however are conspicuous, lying between the testes 
and the yolk glands in the posterior third of the body. They curve 
round the posterior borders of the testes and their ends are usually 
turned in towards the middle line, and do not quite reach the tip of 
the tail. 
The genital aperture lies to one side of the oral sucker, on the level 
of its posterior border. Usually it is on the right side but not infre¬ 
quently on the left. The cirrus pouch is a comparatively enormous 
structure stretching from the genital aperture obliquely backwards to 
near the middle of the ventral sucker. Its course is somewhat sinuous 
and its breadth fairly uniform. It contains a large vesicula seminalis, 
a short pars prostatica and a moderately long ductus ejaculatorius. 
The testes are situated in the posterior third of the body, separated 
from the tip of the tail by a space almost equal to their length. They 
lie alongside each other but somewhat oblique, the left being in advance 
of the right. They are elongated oval in shape and of large size, 
measuring 0-23 x 0-135 mm. They are overlapped by the uterus only 
to a very small extent, along their anterior border. , 
The ovary lies on the right side about midway between the ventral 
sucker and the testes, and entirely obscured by the uterus. It is a 
small globular body measuring about 0-075 mm. The yolk glands are 
entirely lateral and confined to the outer side of the intestinal diverticula. 
They extend from the anterior border of the ventral sucker to the ends 
of the intestinal diverticula. The follicles are of moderate size. 
The uterus, as already mentioned, is extremely voluminous. It 
consists of a narrow highly convoluted tube. In younger specimens it 
is thrown into the form of a semicircular festoon surrounding the 
ventral sucker except on its anterior border. The convolutions obscure 
the ovary and intestinal diverticula and overlap the testes to a variable 
extent. In the most mature specimens the uterus increases enormously 
in extent and the individual convolutions become largely obliterated. 
Additional convolutions are thrown down over the testes and in many 
specimens the latter are almost entirely covered. The anterior part 
of the body also becomes filled with the uterus right up to the oral 
sucker with the result that the cirrus pouch is completely obscured. 
The mass of eggs extends up to the genital aperture. In such specimens 
