31 
(In the previous description the coeca were described as not reaching 
so far). Between the termination of the coeca is a pear-shaped 
excretory vesicle reaching nearly to the level of the hind end of the 
testes and opening posteriorly and slightly dorsally. 
The genital opening is a transverse slit situated in the middle 
line immediately in front of the ventral sucker. At times it is very 
difficult to see, but usually in the living worm it can easily be made 
out as it is constantly opening and shutting. This leads to a small 
genital sinus, into which open the male and female ducts, male on 
the right and female on the left. The testes are longitudinally oval 
bodies, 0-08 mm. in length and 005 mm. broad, occurring ventrally 
to the intestinal lobes and a little nearer the posterior end of the 
body than the ventral sucker. They are symmetrically placed one 
on each side of the body. From each testis runs a narrow vas 
deferens, and these join the vesicula seminalis behind the ventral 
sucker. The vesicula seminalis is divided into two nearly equal 
parts by a constriction, and lies completely within the club-shaped 
cirrus sac. The latter is dorsal to the ventral sucker, in pressure 
preparations it may be seen either to the right or left side. 
It contains in front of the vesicula seminalis, a long ductus ejacula- 
torius, the first part of which is a weakly developed pars prostatica 
surrounded by gland cells, and the next part is armed for about 
a quarter of its length with sharp spines with round bases; the 
terminal part is unarmed and very much curled up. This duct 
appears to be a protrusible cirrus, although I have not seen it 
exserted. The ovary is a circular body generally situated im- 
mediately in front of the right testis and is slightly smaller than 
that organ. Dorsally it gives off a long oviduct which makes a 
twist before giving off’ a receptaculum seminis and a Laurer’s canal. 
The vitelline duct opens into it just after it gives off the receptaculum 
seminis. The latter organ when full of sperms is quite conspicuous 
and of a roundish form. In some specimens it is hardly visible, 
and the sperms are to be seen moving about in the oviduct and in 
Laurer’s canal. The vitellaria take up almost the whole of the rest 
of the body, extending dorsally from the extreme posterior end to 
the level of the centre of the pharynx, only leaving a small median 
part uncovered. They partly cover the intestinal coeca ventrally. 
They consist of large lobules indistinctly connected by lateral 
longitudinal vessels from which a thick transverse branch runs 
across each side in the region of the ovary to unite in a large 
receptacle from which a duct enters the oviduct. After receiving 
