340 
Queensland Trematodes 
usually elongated longitudinally and which has an elongated aperture, 
measures 0'25 mm. in diameter. The ventral sucker which is usually 
transversely elongated measures 0T8 mm. in diameter. The ratio of the 
suckers is therefore considerably less than 3:2. The ventral sucker 
is situated at a distance of 0'57 mm. from the anterior end. 
The pharynx is almost contiguous with the oral sucker and measures 
0 08 mm. in length and breadth. The oesophagus is twice as long as 
the pharynx, and the intestinal diverticula extend a little beyond the 
middle of the body. 
The excretory vesicle extends forward to a short distance behind the 
receptaculum seminis. 
The genital aperture is situated in the middle line a little in front 
of the intestinal bifurcation. The short slender cirrus-pouch reaches 
back to just in front of the ventral sucker. It contains a small vesicula 
seminalis, an almost globular pars prostatica and a long ductus ejacula- 
torius. 
The testes are situated on the level of the ventral sucker and 
overlapping it to some extent. They are rarely symmetrical, the left 
usually being a little in advance of the right. They are irregularly 
rounded bodies measuring about 021 x 0T4 mm. There is considerable 
o 
variation in their position, size and shape. 
The ovary lies on the left side almost immediately behind the left 
testis. It is a large rounded or somewhat heart-shaped body measuring 
O'lo mm. in diameter. On its inner side lies the shell-gland complex with 
a small receptaculum seminis. The yolk glands extend from the oral 
sucker to near the end of the intestinal diverticula. Behind the ventral 
sucker they are confined for the most part to the outer side of the diver¬ 
ticula, but in front of the sucker they spread out, overlapping the 
intestines and in some cases almost uniting dorsally to the oesophagus. 
The uterus is very voluminous and contains a large number of eggs. 
From the ovary it winds back on the left side to the posterior end of 
the body. It returns on the right side but about the middle of the body 
it forms a convolution which extends right across the body. It then con¬ 
tinues up on the right side, crossing the right testis. The eggs measure 
0'033-0'041 x 0’024-0'028 mm., the average being 0 038 x 0'026 mm. 
The species is subject to a number of small variations which chiefly 
affect the position of the genital glands. 
Remark has already been made on the variability of the testes. 
The same applies to the ovary and the receptaculum seminis. The 
yolk glands also vary in extent. In one case they were entirely absent 
