1909. | POSTCAVAL VEIN IN MAMMALS. 519 
The posteriorly situated point of opening of the spermatic and 
ovarian veins in the genus Sciurus is, so to speak, a less exaggerated 
condition of these veins than that found in Gerbillus and Zapus, 
and is suggestive of the conditionswhich appears to be universal 
among the Marsupials. 
In Notiomys cervinus (of which I have dissected two examples, 
both females) the renal veins show the usual asymmetry, the 
Text-fig. 139. 
Postcaval vein and its branches in Zapus hudsonianus (A), Gerbillus egyptius (B), 
and Georhychus capensis (C). 
Lettering as in text-figs. 132, 133, 137. 
right entering the postcava higher up than the left. In both 
specimens the right ovarian vein entered the postcaval at a point 
pretty well opposite to the entrance of the left renal. The left 
