Il6 ALLEN 



The outer subclavian vein penetrated the scapula with the cor- 

 responding artery and joined the internal subclavian vein in 

 formincr the common subclavian trunk, which terminates in its 

 respective horn of the kidney. 



The vessel designated as the anterior ventral artery (fig. 36 ; 

 Ven.A.) arises from the ventral union of the second right and 

 left efferent branchial arteries ; principally, however, from the 

 second left efferent branchial artery. After passing over the 

 combined trunk of the third and fourth afferent branchial ves- 

 sels it gives off the pharynx artery. This vessel (fig. 36 ; 

 Phar.A.) supplies the phar3'nx region, and soon sends off the 

 coronary artery {^g. 36; Cor. A), which passes along the dorsal 

 side of the ventral aorta to the heart. In all other genera studied 

 the pharynx artery arose directly from the second or the third 

 efferent branchial arteries. The anterior ventral artery evi- 

 dently corresponds to the ventral artery of the other species ; 

 except that it extends only to the origin of the pelvic arch. In 

 addition to giving off the phar3-nx artery it sends off branches 

 to the sterno-hyoideus muscle and anastomoses with the 2 hypo- 

 branchial arteries. It would be possible, however, in Anoplo- 

 -ponia for blood in the anterior ventral artery to reach the ventral 

 fins by passing through the right hypobranchial artery into the 

 posterior ventral artery. By the separation of the right hypo- 

 branchial from the subclavian we would have in the anterior 

 ventral, right hypobranchial, and posterior ventral arteries an 

 irregular shaped vessel corresponding somewhat to the ventral 

 artery of the other genera. 



As in Scbastodes, there is in addition to the main inferior jugu- 

 lar and left branch, a right inferior jugular, which drains the 

 ventral branchial muscles from the right side and empties into 

 the right precava. 



Civli'aco-incsenicn'e Artery. — This trunk {'C\\i,. 37 ; Cce.Mes.- 

 A.) upon reaching the oesophagus separates into the coeliac and 

 mesenteric arteries respectively. The mesenteric artery soon 

 divides into intestinal artery^) and a short stem from which the 

 rigiit and le_ft g'astric arteries have their source. The latter 

 vessel (figs. 37 and 38; L.Gas.A.) makes a cephalic curve 

 across the oesophagus and continues on the left side of the 



