380 
A Tri-Radiate Tapeworm 
corresponded with the description given by Neumann. The scolex was 
T7 mm. long by 3 mm. wide. The six suckers varied slightly in size 
being approximately 1-35 mm. long by 1-1 mm. wide: their openings 
had a diameter of 0-368 mm., and their posterior lobes were 0-86 mm. long 
by 0-71 mm. wide. The length of the central proglottides was 0-63 mm., 
of the posterior 0-43 mm. 
Excretory System. 
The excretory system consists of longitudinal dorsal and ventral 
vessels, uniting in the scolex to form a definite excretory plexus. In 
the remainder of the strobila they extend from the neck posteriorly, 
one dorsal and two ventral vessels in each arm. The dorsal vessel 
continues practically unchanged throughout the entire course. It 
runs internal to the nerve and gives off a few branches which end blindly 
in the parenchyma. There is no trace of a commissure connecting it 
with any other vessels. The ventral vessels consist of two in each arm, 
lateral and slightly internal to the longitudinal nerve trunk. In the 
middle of the proglottis, each bends outwards nearly to the tip of the 
arm and then returns to its former position. 
Fig. 1. Transverse section through posterior part of neck. For explanation 
of lettering see text. 
A transverse commissure internal to the nerve connects the two 
vessels in the posterior part of each proglottis. In this posterior portion 
of the proglottis, each ventral vessel gives off one or more branches 
