88 VETERINARY PARASITOLOGY 
prominent and forms a marked convexity. The uterus 
is a long median tube, and has a number of lateral 
branches, which are given off after the manner of an 
umbel. 
The cystic stage takes the form of a Cysticercus, the 
Cysticercus pisiformis, which is found attached to the 
mesentery of rabbits or situated in some other portion of 
the peritoneal cavity. 
The Cysticercus pisiformis is of the size and shape of 
a pea, and shows on inspection the invaginated head, 
which exactly corresponds in structure with that of 
Tenia serrata. Occasionally a Cysticercus pisiformis is 
found elongated in shape, and even a few segments may 
be present behind the head. 
A dog may become infected by ingestion of the cysts, 
eight to ten days after desiccation. The cycle is com- 
plete in eight weeks, when the dog will be voiding ripe 
segments and ova. 
Tenia Marginata.—This is also a fairly common 
parasite of the dog’s intestine. It is a large worm, and 
is only with difficulty to be distinguished from Tenia 
serrata. Its length is from 4 to 6 feet. 
The head is not wider than the neck, and so does not 
project on either side. It carries from thirty to forty- 
four hooks. In Tenia marginata the guards of the 
hooks are not bifid, as in Tenia serrata, but S-shaped. 
The segments of the anterior portion are much broader 
than long, but in the terminal half the reverse is the 
case, though even then they are broader and shorter 
than those of Tenia serrata, and the posterior border 
of each segment shows a somewhat wavy outline. The 
genital pore is much less prominent, and the outline is 
therefore more regular. 
The cystic form is a Cysticercus, the Cyszicercus 
tenuicollis, which is found in the peritoneal cavity, and 
occasionally in the thorax of sheep, oxen, and some- 
