650 
Proceedings of Royal Society of Edinburgh. 
SESS. 
walls, tlie vagina passes out, on the ventral side of the male 
papilla. The vagina is large at the beginning, and surrounded 
by a strong musculature, essentially formed by circular fibres, 
which cross each other. At the entrance into the internal paren- 
chyma, the diameter of the female canal diminishes, to swell 
again as soon as it has passed the water-vascular system. The 
second extension, spindle-shaped, is equally muscular ; hut here it 
is the longitudinal fibres which prevail. It is a receptaculum 
seminis similar to that of P. torulosa. From this point the 
vagina goes towards the middle of the proglottis to meet with 
the canal that comes from the ovary. Before joining, the canal 
narrows suddenly, presenting at this point a stronger musculature. 
It is probably a sphincter which prevents the spermatoids return- 
ing. The sexual glands are composed of an ovary, lohed, situated 
ventrally, and occupying all the length and breadth of the 
parenchyma placed between the water-vascular system. At the 
origin of its canal is situated a muscular funnel : an egg-aspirator. 
The vitelligenous gland, situated in the middle, lies ventrally, and 
is small; it is placed before the ovary. Where the vitelloduct 
meets the oviduct is to he found a shell-gland from which the 
canal runs towards the dorsal side to open into the uterus, which 
has the same shape as in P. torulosa (fig. 7). In the last pro- 
glottides the uterus fills the whole internal parenchyma. I could 
not study the hooks of the embryo, the eggs not being in a 
sufficiently advanced state. As I had not the last proglottides, 
I cannot say if there are three shells surrounding the eggs. 
It is very probable that in this species the fecundation of the 
eggs is often produced by the male organ of the same proglottid; 
but the very complex disposition of the musculature of the cloaca, 
and the peculiar development of the male papilla, lead me to 
believe that fecundation may also take place between different 
proglottides. 
