470 WILLIAM NICOLL. 
breadth of ‘87 mm. Other specimens were not quite so 
attenuated, but the breadth is rarely more than one third of 
the length. Immature specimens were found up to 1:05 mm. 
in length. The body usually tapers considerably towards 
each end. The oral sucker measures ‘34 mm, and the ventral 
sucker ‘51 mm.ina specimen 3 mm. long. The proportion is 
constantly 2: 3 instead of 1:2 asin F.fellis. Both suckers 
are globular. The ventral sucker les a little in front of 
the middle of the body. 
The alimentary system resembles that of F.fellis. The 
pharynx is somewhat smaller—15 by *12 mm. The cesophagus 
is practically absent. The diverticula extend along the 
sides of the body and terminate at the posterior border of 
the testes, therefore at a considerable distance from the 
posterior end of the body. This feature is evidently shared 
by the genus in common with the genus Steringophorus, 
although it is not apparent at first sight in the case of Fello- 
distomum fellis,in which the testes are placed very near 
‘the posterior end of the body. 
The excretory system corresponds with that of F, fellis, 
but the main stem of the vesicle is much elongated. 
The genital aperture is placed on a prominent papilla 
in the same situation as in F. fellis, and the cirrus- 
pouch has the same structure. The testes are situated not 
far behind the posterior border of the ventral sucker, and at 
a considerable distance from the posterior end of the body. 
They have the same shape and disposition as in F. fellis. 
The ovary has also the same situation. The yolk-glands, 
however, le entirely in front of the ventral sucker and 
extend along the sides of the body from the anterior border 
of the sucker to the level of the pharynx or intestinal bifurca- 
tion. They form a broader and more compact group than do 
those in F. fellis. The uterus describes a few windings in 
front of the testes, then runs back between them very nearly 
to the posterior end of the body. In this part it forms a 
single descending and ascending loop with little or no con- 
volution. On again reaching the level of the ovary it makes 
