210 The Alligator and Its Allies 



three short branches, with the external jugular, 

 ej, to be described later. Its distribution in 

 the cranial cavity could not be determined in the 

 available material. At the point of entry of the 

 internal jugular the precava passes laterad for a 

 short distance and then divides into two more or 

 less equal branches, the above-mentioned external 

 jugular, ej, and the subclavian, s, of which the 

 latter will first be described. 



The subclavian, s, of course, returns blood from 

 the regions of the shoulder and arm. On reaching 

 the body wall, where it might be called the axillary, 

 ax, it receives, on its posterior side, a large thoracic 

 vein, t, which returns blood from the thorax, 

 shoulder, and skin. The thoracic receives a 

 branch from the posterior surface of the arm, 

 which might be called the postbrackial, pb; this 

 postbrachial may be traced, as a rather small 

 vessel, to the hand; at the elbow it is connected, 

 by one or more small branches, with the brachial. 



Just distal to the thoracic the axillary vein 

 receives two fairly large vessels, the subscapulars, 

 sc, that return blood from the shoulder and 

 upper arm. After receiving the subscapulars, 

 the axillary may be followed into the upper 

 arm as the brachial, br. As has been said, the 

 brachial and postbrachial anastomose near the 

 elbow, and in this region the former receives a 

 small vessel that extends parallel to it from the 

 manus. 



