UNIVERSITY OF CALIFORNIA PUBLICATIONS 



IN 



ZOOLOGY 



Vol. 18, No, 16, pp. 479-484, 2 figures in text August 10, 1918 



THE SUBCLAVIAN VEIN AND ITS RELATIONS 

 IN ELASMOBRANCH PISHES 



BY 

 J. FRANK DANIEL 



^ AUG 21^ 



Introduction ^s,^'^'^"^/ ^'^'s^_^€^> 



C. F. O'Donoghue (1914) has called attention to the confusion in 

 the literature on the subscapular and subclavian veins of the elasmo- 

 branch fishes, and has in a way straightened out the difficulty by show- 

 ing that the subscapular enters the postcardinal sinus and that the 

 subclavian, formed by the union of the brachial and lateral abdominal 

 veins, enters the duct of Cuvier. 



In my study of the Elasmobranchs I have been attracted to this 

 problem, since in different types the subscapular varies in extent and 

 the subclavian differs greatly as to the relative amount of blood which 

 it receives. In certain cases the condition in both of these vessels is 

 as O'Donoghue and T. Jeffrey Parker (1886) have shown for Scyllium 

 canicula and Mustelus antarcticus respectively. In these types the sub- 

 scapular vein enters the postcardinal sinus and therefore none of its 

 blood passes to the heart by way of the subclavian. In others, how- 

 ever, the subclavian may receive all of the blood from the whole of 

 the subscapular system. In still others an intermediate condition may 

 obtain in which a subscapular vein bridges postcardinal and lateral 

 abdominal systems, so that blood entering it may go to the heart by 

 either of these systems, depending upon whether it enter the sub- 

 scapular dorsally or ventrally. 



Material 



As material for study I have had access to Heptanchus (Notorhyn- 

 chus) maculatus ranging from two to nine feet in length and Squalus 

 suckUi and Mustelus henlei of about two feet in length. 



