356 THE AMERICAN NATURALIST. | (Vor. XXXIX. 
its one end into the left lateral vein, and at its other into a large 
anterior renal portal component, which was virtually a direct 
continuation of the renal portal vein itself forward on the dorsal 
body wall. Jourdain ('59) describes a similar anterior component 
of the renal portal system. 
The extreme posterior end of the lateral vein was found to be 
not injected. 
V. Raia levis: very large female. 
1. Renal portal system injected, via the caudal vein, with 
blue starch. 
2. Left lateral vein injected posteriorly with red celloidin. 
A particularly full injection of the branches of the posterior 
part of the lateral vein was secured. The mass appeared on 
the walls of the cloaca and rectum in an anastomosing network 
of fine vessels, which were traceable along the rectum to a region 
about one centimeter anterior to the duct of the rectal gland. 
The mass was seen also in small vessels on the ventral margin of 
the mesorectum, and a considerable quantity of it passed through 
the rectal extension of the cardinal sinus into the main part of 
that sinus. 
The left pelvic fin was cut, as in preceding cases, and the red 
mass escaped from small vessels along its median edge. 
The dissection of this animal demonstrated clearly a connec- 
tion between the venous network on the rectum and the cardinal 
sinus. The lateral vein was traced forward a short distance on 
the side of the rectum and there broke up into fine branches 
which anastomosed with vessels of the network. Along the 
margin of the mesorectum, in the region of the base of the 
rectal gland, several small vessels resolved themselves out of the 
network and communicated with the posterior end of the rectal 
extension of the cardinal sinus. 
From the pelvic fin the lateral vein received two large 
trunks and one very small vein (see Fig. 4). The largest trunk 
emerged from the fin just posterior to the iliac process of the 
girdle, corresponding, therefore, with the one vein found in II 
and with the posterior one of the two veins found in I. This 
