346 
Entozoa of Fishes 
level of the posterior end of the cirrus-pouch. They cover the intestinal 
diverticula and overlap the testes to a slight extent. The variation in 
the anterior limit of the yolk-glands is very small and they never 
reach the ventral sucker as is shown in Miss Lebour’s figure of 
Pharyngora retractilis. 
The uterus occupies the space between the ovary and the ventral 
sucker but it is poorly developed. It consists of only a few small 
convolutions and the ova lie freely in them. The ova rarely exceed 50 
in number. They are of regular shape, with uniform shell slightly 
thickened at the anopercular pole. They vary greatly in size, the 
limits in length being 0072—0091 mm. and in breadth 0042— 
0053 mm. The average dimensions are about 0 - 0Sl x 0 047 mm. 
The larva of this species was obtained from some material bi’ought 
in by a coarse-meshed tow-net at Plymouth in August. It was quite 
free when found and there was no evidence to show that it had escaped 
from any of the numerous Copepods and larval Crustacea included in 
the haul. A number of them were examined but no cysts could be 
found. The specimen measured about 0'4 mm. and there could be no 
mistake as to its identity. The peculiarly shaped oral sucker, the 
conspicuous pigment patches, the long oesophageal tube and the large 
excretory vesicle, extending well in front of the ventral sucker, all 
combine to render its identity practically certain. 
From the foregoing it is evident that Miss Lebour’s original definition 
of the genus Pharyngora requires modification in certain important 
points. The changes and additions which require to be made are as 
follows: 
Lepocreadiinae of delicate structure and elongated body; pigment 
patches alongside the pharynx, persisting in the adult; prepharynx 
comparatively short, pharynx small, oesophagus short but continued by 
a long pseudo-oesophagus lined with intestinal epithelium; excretory 
vesicle greatly elongated; genital aperture on the left anterior border 
of the ventral sucker; genital sinus capacious, ovoid in shape; vesicula 
seminalis externa lying free in the parenchyma and not surrounded by 
any specialized membrane or glands; cirrus-pouch elongated, extending 
behind the ventral sucker; vesicula seminalis in terminal communication 
with the pars prostatica. 
Type and only species Pharyngora bacillaris (Molin 1859). Habitat, 
intestine of marine fishes. 
It is also apparent that, as already indicated by Odhner, it falls 
naturally into the sub-family Lepocreadiinae, but its inclusion 
