TWO NEW MAMMALIAN CESTODES, 425 
the egg; the large receptaculum seminis, and the vagina aborting 
in later segments. There are, however, important points of 
difference which mark C. lagorchestis as a distinct species. In the 
first place, there are only two longitudinal excretory canals and 
one transverse excretory canal in each segment in (. lagorchestis, 
whereas in C. zschokkei there are three longitudinal excretory 
canals and two transverse canals to each segment. The most 
important contrasts are found in the reproductive organs, and 
may be tabulated as follows :— 
C. lagorchestis. C. zschokkei. 
(1) Vas deferens a slender tube 
with an oval swelling, the vesi- 
cula seminalis, near entrance into 
cirrus-sac. Vas deferens recurves 
to receive ducts from testes. 
Vas deferens much swollen through- 
out its length to form an elongate 
vesicula seminalis. Vas deferens 
passes straight to testes. 
(2) Cirrus-pouch extends across the 
longitudinal canals and nerve 
towards the median field for half 
its length. 
(3) Testes situated dorsal to pro- 
jection of cirrus-pouch in inner 
parenchyma between ventral 
longitudinal excretory canal and 
inner termination of cirrus- 
pouch. 
(4) Ovary dorsal to receptaculum 
seminis, and consisting of a circle 
of “Indian club” shaped tubules 
Cirrus-pouch does not extend in- 
wards over excretory canals and 
nerve, 
Testes more median, situated dor- 
sal to ovary, receptaculum 
seminis, and vitelline gland, and 
not extending outwards to longi- 
tudinal excretory canal. 
| Ovary on same plane as receptacu- 
lum seminis, nearer median field 
consisting of an irregular mass 
Opening into a common reservoir not showing tubular arrangement. 
by slender necks. 
(5) Two uteri, whose origin is dis- 
tinct as separate tubules, but 
which with increasing age 
approach each other and fuse in 
the median field. 
Uterus originates as a single tube. 
The only resemblance with C. kuvaria Shipley (7) is that the 
cirrus-pouch is much elongated and stretches over excretory 
vessels and nerve into the inner parenchyma. Also there is a 
large shell-giand in both species, and in ripe proglottides the 
uterus fills the whole of the inner parenchyma, not extending 
over the excretory canals and nerves but pushing these nearer 
the margin. The contrasts are well marked. In C. kuvaria the 
excretory system consists of extraordinarily wide channels, two 
large ventral and one smaller dorsal vessel. and the hind end of 
each proglottis shows a tongue-like projection of parenchyma 
into ventral vessel which lies on a projection of the wall of the 
latter and forms a barrier which prevents a backward flow of 
excretory fluid. No such structure is observed in C. lagorchestis. 
