Anatomy of Notoryctes typlilops. 105 



deferens (z'.d.) to the root of the latter, when the blood vessel 

 turns forwards, anastomosing by sometimes a double branch 

 with a corresponding vein from the bladder {v). These two veins 

 then run forwards along the ureter, until, when they reach the 

 hinder edge of the kidney, they turn inwards (ventral to the 

 abnormal renal vein when present), both entering the normal 

 renal vein on the left side, while on the right the spermatic vein 

 enters the right renal vein, and the vesical opens directly into the 

 posterior vena cava. The blood from the hind limb is returned 

 by the deep femoral and the superficial femoral veins, the former 

 forming the external iliac vein, which receives a number of vessels 

 from the muscles. Into it open the ilio-lumbar veins, two or three 

 in number, the superficial and deep circumflex veins, and the long 

 saphenous vein, all of which appear to have the same distribution 

 and relative positions as in mammalia generally. The internal 

 iliac veins are large and correspond very closely with the arteries 

 in their branches and distribution, except that the well-marked 

 vesical veins are branches of these internal iliac veins instead of 

 belonging to the external iliac system, as do the corresponding 

 arteries. Opening into the left internal iliac vein was occasion- 

 ally a small but distinct median vessel bringing back blood from 

 the testes and anal glands and from the surrounding fatty tissue. 



Comparison witJi other For//is and Summary. 



I regret that the literature obtainable here is somewhat scanty 

 on the blood vascular system, so that I am not able to make as 

 thorough a comparison as would otherwise be the case. The 

 chief points of interest, however, are as follow : — 



(1) The method of origin of the subclavian and carotid arteries 

 from the aortic arch conforms in each of its two variations in 

 Notoryctes, to one or other of the two marsupial types. ^ 



(2) The blood vessels of the anterior limb are practically 

 normal, except in size. They are larger than usual in Noto- 

 ryctes, probal)ly associated with the burrowing function of the 

 fore-limb. 



(3) In the Kangaroo and Vulpine Phalanger,'-^ and also in 



1 Owen : Comparative Anatomy of Vertebrates, vol. iii., p. 539. 



2 Loc. cit., pp. 538, 540-1. 



