92 ALLEN 



between the ventral aorta and the transversus ventralis muscle, 

 and when the posterior edge of this muscle is reached, which 

 is about midway between the last pair of afferent branchial 

 arteries and the ventricle, the inferior jugular bifurcates into a 

 very large 7-ight and a much smaller left htferio?' Jugular vein 

 (PI. II, fig. 12 ; R and L.I.J.V.). The course of each of these 

 veins is then obliquely caudad, running along the ventral side 

 of the pharynx close to the pharyngo-clavicularis internus mus- 

 cle. They terminate by emptying into their respective pre- 

 caval veins. Throughout their course they receive branches 

 from the pharynx, the phayngo-clavicularis' internus and ex- 

 ternus muscles, and shortly before dividing, the inferior jugular 

 received branches from the pharyngo-hyoideus and transversus 

 ventralis muscles, and the coronary vein. 



The coronary vein (PI. II, fig. 12; Cor.V.) arises from a 

 dorsal and a ventral branch, which run parallel with their 

 respective arteries. The dorsal vessel collects the venous blood 

 from the anterior part of the ventricle and the bulbus arteri- 

 osus ; while the ventral branch drains only the bulbus. About 

 midway between the ventricle and the first pair of afferent 

 branchial arteries these 2 branches unite on the left side of the 

 ventral aorta in forming the main coronary vein, which finally 

 empties into the inferior jugular shortly after it emerges from 

 the last pair of afferent branchial arteries. 



Beside this coronary vein, which drains the ventral aorta, 

 bulbus, and anterior part of the ventricle there is another sys- 

 tem of coronary veins, which terminate by emptying directly 

 into the auricle. The outer layer of the ventricle is a mass of 

 capillaries, which become collected on the ventral side into 4 

 or 5 veins that pass around to the dorsal side where some of 

 them anastomose, forming 2 or 3 vessels, which penetrate the 

 auricle close to the auriculo-ventricular valve. In one speci- 

 men several small veins were noticed to arise on, and penetrate 

 the dorsal surface of the auricle. 



In Sebastodes melanops^ beside the large right and the smaller 

 left inferior jugular veins, 2 other veins, laterad to these, were 

 observed. They arose from the pharyngo-clavicularis internus 

 and externus muscles, and passed caudad to empty into their 

 respective precaval veins. 



