1918] Daniel: The Subclavian Vein in Elasmohranch Fishes 481 



studied in median view. From such a section the lateral abdominal 

 and subscapular veins are seen to advantage, and all vessels may be 

 dissected without great difficulty. When color is needed a starch mass 

 may be injected into the large brachial vein as it leaves the fin. In 

 this injection the mass is prevented from running out at the cut ends 

 of the vessels either by plugging the ends with cotton or by ligature. 

 After the maas has hardened for two days the material is ready for 

 dissection. 



Observations 



The conditions which I have found in Mustelus henlei, are in the 

 main so much like those given for the Australian form of Mustelus as 

 not to require refiguring. The subscapular sinus receives the lateral 

 cutaneous vein and empties into the postcardinal sinus; none of its 

 blood, therefore, reaches the heart by way of the subclavian vein. 

 The brachial vein from the pectoral fin joins the lateral abdominal 

 and the two form the subclavian which enters the duct of Cuvier, but 

 not in common with the inferior jugular as reported for Scyllium by 

 'Donoghue. 



In one important respect, however, my observations differ from 

 those recorded for Mustelus antarcticus and Scyllium.. In addition to, 

 but separate from the subscapular sinus at the distal part of the 

 scapular cartilage, there is an abbreviated subscapular vein which 

 extends along the ventral and posterior margin of the scapula and 

 enters the brachial vein. In other words the subscapular vein is made 

 of two distinct components : first, a distal sinusoid around the tip of 

 the scapular cartilage, which receives the lateral cutaneous vein and 

 joins the postcardinal sinus, and secondly an abbreviated portion of the 

 subscapular vein, which as a smaller vessel passes down the postero- 

 median margin of the scapular cartilage to join the brachial vein. 

 From this subscapular vein blood enters the duct of Cuvier through 

 the subclavian vein. 



In Heptanchus the subscapular (fig. 1, s. sc. v) begins at the tip of 

 the scapula as a large sinus, passes unbroken down the entire length 

 of the postero-medial margin of the scapula and enters the brachial 

 vein (hr.v.) at a place where the latter crosses obliquely over the 

 shoulder girdle. The principal tributary of the subscapular is the 

 lateral cutaneous vein (1. c. v.) which receives blood from the skin and 

 empties it into the dorsal part of the subscapular sinus. But since the 



