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THE AMERICAN NATURALIST [Vol. XL 



lie as far back as the cloaca or even posterior to it. In the neigh- 

 borhood of the cloaca, the dorsal aorta gives off a pair of large 

 arteries, the iliacs {II.) which are continued into the posterior 

 appendages as the sciatic arteries {Sci.). Each iliac artery gives 

 off, a short distance from its origin, a vessel, the posterior epigastric 

 {P. Epi.), which is chiefly distributed to the ventral body wall, 

 but which also sends blood to the pelvic region (Pel.). A short 

 distance distal to the posterior epigastric, each iliac gives off a 

 small artery to the pelvic region. From the right iliac an addi- 

 tional artery is given off, distal to those just described, to the 

 bladder and the posterior end of the rectum. This is the hypo- 

 gastric (Hy.). 



Posterior to the point of origin of the iliac arteries, the aorta 

 continues backward, with diminished caliber, as the caudal 

 artery (F.) to supply blood to the tail. Besides several pairs 

 of renal arteries, there is given off from the aorta, just back of 

 the iliacs, a pair of arteries (Pel.), to supply blood to the dorsal 

 region of the pelvis. This completes the description of the more 

 important vessels of the arterial system. Without stopping to 

 describe the distribution of the more minute vessels, the venous 

 system will now be described. 



The Venous System 



The venous system is much more difficult to work out than the 

 arterial system, due chiefly to the difficulty of obtaining good 

 injections, especially in the region anterior to the heart. 



The venous system, as described in this paper, will exhibit 

 more differences from that described by Dr. Osawa for the Jap- 

 anese giant salamander than were seen in connection with the 

 arterial system. The veins of the posterior region of the body 

 were injected, without csjXH-ial difHculty, as follows: tlie abdom- 



practically the entire system was (illed; and tlir posterior vena 



into the caudal vein. The veins of the anterior parts of the body 

 were injected through the anterior venae cavie, and it was here 



