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PROFESSOR T. J. PARKER ON THE 
backwards, and divides into a femoral artery (Fern. A.) distributed to the pelvic fin, 
and a posterior lateral artery (Post. lat. A.) which extends forwards, accompanying 
the lateral vein, and contributing to the supply of the abdominal walls. 
13. The caudal artery. 
At the commencement of the haemal canal of the caudal vertebrae, the dorsal aorta 
becomes the caudal artery (Plate 34, fig. 1 ; Plate 37, fig. 25, Caud. A.), which passes 
to the end of the tail, supplying its various tissues. 
II. The Veins. 
The investigation of the veins of Elasmobranchs is attended with so much more 
difficulty than that of the arteries, that it is hardly surprising to find the published 
accounts of them generally wanting in detail, besides being actually inaccurate in 
many particulars. 
The veins of Mustelus may be classified, mainly on embryological grounds, as 
follows : — 
A. System of the sub-intestinal vein. 
i. Renal portal section. 
1. The caudal vein. 
2. The renal portal veins. 
a. The posterior oviducal veins. 
h. The posterior spinal veins. 
ii. Hepatic portal section. 
3. The hepatic portal vein. 
a. The intra-intestinal vein. 
h. The ventral intestinal vein. 
c. The posterior lieno-gastric vein. 
d. The gastro-intestinal vein. 
a. The dorsal intestinal vein. 
ft. The anterior lieno-gastric vein 
y. The anterior gastric vein. 
e. The ventral gastric vein. 
4. The hepatic veins and sinus. 
