334 
Entozoa of Fishes 
In the yolk-glands we find the chief distinguishing character of the 
species. In the posterior part of the body they are exclusively marginal 
and rarely extend to the inner side of the intestinal diverticula. In the 
post-testicular space they do not unite and thus leave a vacant space 
behind the posterior testis. There is however occasionally a certain 
amount of proliferation. In no case do they ovexlap the testes or ovary. 
They are always continuous at the level of the ventral sucker and immedi¬ 
ately in front begin to proliferate to such an extent that they extend right 
across the body. This extension however is entirely under the dorsal 
surface. They thus form a dorsal layer which extends from over the 
ventral sucker to well in front of the intestinal bifurcation. The 
anterior limit of the marginal follicles is about the level of the middle 
of the pharynx. Sometimes they barely reach the pharynx. 
The uterus is confined in the same way as in L. varia and never 
contains more than 20 ova. The latter are a trifle shorter and broader 
but have otherwise the same shape. They measure 0’081—0'088 mm. 
in length by 0 - 041—0‘054 mm. in breadth: average 0’083 x 0'049 mm. 
To sum up the differences between the two foregoing species we 
find that the yolk-glands are differently disposed, that the ventral 
sucker is nearer the middle of the body in L. alacris and that the 
suckers are proportionally somewhat larger. The testes and post- 
testicular space are somewhat smaller and the oesophagus is longer. Iu 
addition L. alacris is a much smaller species than L. varia and begins 
to produce ova at a considerably smaller size (0'8 mm. as contrasted 
with T25 mm. in the case of L. varia). 
With the addition of these two species the original definition 
(1909 a, p. 450) of the genus Lebouria requires slight modification as 
follows: Genital aperture slightly displaced from the middle line 
towards the left. Testes usually oblique, the anterior one being to 
the left. Ova measuring 0'065—0 09 x 0 - 035—0 05 mm. 
Genus iii. Podocotyle (Duj.) Odhner 1904. 
Species 1 . Podocotyle atomon (Rud.) 1802. 
This species has already been exhaustively described by Odhner 
(1904, p. 320), Lebour (1907, p. 36) and myself (1907, p. 73, 1909 a, 
p. 451, 1909 6, p. 6). It is the commonest parasite of inshore fishes. 
At Millport it was found in Gottus scorpius, Cottus bubalis, Pholis 
gunnellus, Gadus pollachius, Gadus virens, Pleuronectes limanda and 
Pleuronectes platessa. 
