W. Nicoll 
113 
average O'115 x 0'042 mm. Cuticular spines, of small size, are present 
on the neck as far back as the anterior border of the ventral sucker. 
Behind the sucker the skin is entirely devoid of spines. 
The globular oral sucker has a diameter of 04 to 045 mm. The 
large ventral sucker is funnel shaped and measures 1'2 mm. in diameter 
by 1'6 mm. in length. Its centre lies at a distance of 2'5 to 3'1 mm. 
(average 2'8 mm.) from the anterior end of the body. 
There is a distinct prepharynx about 013 mm. in length, a pharynx 
measuring 0'39 x 0'28 mm. and an oesophagus of 0'84 mm. (075 to 
TO mm.) in length. The diverticula extend to near the posterior end 
of the body. 
The genital aperture lies over the intestinal bifurcation. The 
massive cirrus-pouch is about O'85 mm. long and contains a large, 
slightly constricted vesicula seminalis. The cirrus is of considerable 
length and was found in one specimen exserted to a distance of 2 mm. 
The ovary lies 2'0 mm. (T8 to 2'2 mm.) behind the ventral sucker. 
It is an almost globular body with a diameter of 0'5 mm. Immediately 
behind it lies a large shell-gland. The anterior testis is separated from 
the ovary by a space of 0'8 mm. (0'6 to TO mm.). The two testes 
are contiguous or even overlapping. They are of large size and pecu¬ 
liar shape. They are about equal in size and measure on an average 
1*2 x 0'7 mm. The peculiar shape may be imagined to be due to the 
testes being crushed in the direction of their long axes, so that their out¬ 
line is thrown into twists, or convolutions. The number of these twists 
is practically constant, namely four half-turns. There are thus on 
either side of each testis two deep furrows. The anterior pole of each 
testis is usually directed towards the right side, but it may be reversed. 
The post-testicular space is, on an average, 4'2 mm. in length. 
The yolk glands extend from a short distance in front of the posterior 
border of the ventral sucker to about 0'4 mm. from the tip of the tail. 
They are fairly voluminous in the post-testicular space but do not unite, 
nor do they overlap the testes to any great extent. The uterus 
contains about 100 fairly large eggs measuring O'12 to O'13 x 0'07 to 
0'075 mm. 
This species bears an exceedingly close resemblance to E. austra- 
lasianum Nicoll. The most striking difference, perhaps, is in the shape 
of the testes. In E. sarcinum the elongated testes show a number of 
simple constrictions ; in E. australasianum the testes are much smaller 
and are marked by a simple constriction across their middle. The 
great variation, however, which such a species as E. revolution (Froelich) 
