W. Nicoll 
199 
very short pars prostatica and a comparatively short and straight ductus 
ejaculatorius, no part of which was exserted. The genital aperture is 
situated in the middle line between the intestinal bifurcation and the 
anterior border of the ventral sucker, but decidedly nearer the former. 
The ovary is wedged in between the anterior testis, the venti’al 
sucker and the cirrus-pouch. It is about the same size as the sucker 
(greatest diameter 0T4 mm.) and its outline is almost globular. The 
presence of a receptaculum seminis or Laurer’s canal could not be 
ascertained owing to the enormous number of eggs in the vicinity of the 
ovary. The yolk-glands are situated in the sides of the body at the 
level of the testis. They are slightly asymmetrical, that on the left 
being a little in advance of the other. The latter extends from the 
anterior border of the anterior testis to about 0'7 mm. from the posterior 
end of the body. They appear to have an unusual configuration, the 
follicles being arranged in tubules or rather in one continuous tubule 
which is thrown into a rosette-shaped knot; the rays of the rosette, 
however, are not equal, those directed forward being decidedly longer 
than those directed backward. On ventral view only the lateral aspect 
of the rosette is seen. The yolk-ducts were not observed. 
The uterus, which fills the remainder of the posterior part of the 
body, is extremely voluminous and contains a very large number 
of small eggs. The uterine walls could not be made out distinctly, but 
it seems certain that the uterus is not convoluted, the enormous number 
of eggs being accommodated by a dilatation of the uterine tube. This 
runs from the ovary, on the right side, backwards to the end of the 
body, where it turns and passes forward on the left, overlapping the 
descending limb to some extent. It still retains a considerable width 
even on passing in front of the ventral sucker and it is joined to the 
small genital sinus by a very short vagina. 
From the genital sinus another unusual and peculiar structure 
arises. This is a pear-shaped pouch with a narrow neck, which lies 
between tbe left intestinal diverticulum and the uterus. The latter 
separates it from the ventral sucker. It is smaller than the cirrus- 
pouch, about 0’24 x OTl mm., and appears to contain no structure or 
contents. It seems to be simply a thin-walled sac, and no clue is 
afforded to its function. 
The mature eggs are bright yellow in colour, with oval outline and 
measure on an average 0'024 x 0'013 mm. 
This form possesses several remarkable features which distinctly 
mark it off as a new type. The chief of these are the accessory genital 
