TWO NEW SPECIES OF CESTODES. 265 
sac is somewhat hourglass-shaped through being compressed in 
the middle; but the anterior end, 7. e. that nearest the exterior 
of the body, is not so wide as the posterior end. The cirrus-sac 
has a thick muscular coat, which thins out only posteriorly ; 
this end of the cirrus is thin-walled and globuJar in shape. 
The cirrus-sac of this Linstowia is large, but not so large as 
in L. echidne and L. semoni. In the ripe segments the total 
length of the cirrus-sae and the genital cloaca is between j and 
$ of the body diameter; more anteriorly, where the cirrus-sac 
is not fully formed, but still differentiated from the sperm-duct, 
a where the body is narrower, the length is between 7 and 
3 of the diameter of the proglottid. The end of the cirrus-sac 
lies considerably to the inside of the nerve-cord; it reaches the 
level of the innermost of the longitudinal water- vascular trunks. 
Text-figure 1. 
Linstowia ameive. 
Horizontal section of a proglottid in which the uterine cavities are not 
yet developed. 
g-c. Genital cloaca. O. Ovary between which and testes, ¢, lies vitelline gland, 
not lettered. 
T note, finally, that the lateral nerve-cord, where it is crossed by 
the cirrus-sac, is bent outwards for a space. Soon after issuing 
from the cirrus-sac the sperm-duct, at first only sinuous, forms a 
coil; this region of the vas deferens is surrounded by laxer 
parenchymal tissue than that which pervades the body generally, 
but which presents no glandular characters. 
The vitelline gland of this species presents the usual characters. 
It lies at about the middle of the proglottid antero-posteriorly, as 
well as from side to side. It is smaller in horizontal diameter 
than the ovary, which lies in front of it, or than the mass of 
