252 



ZOOLOGY 



SECT. 



in front of the conns, so that a ventral aorta can hardly be 

 said to exist. Each branchial arch has two efferent branchial 

 arteries. A hyoid artery (hy. art.) is connected dorsally and vent- 

 rally with the most anterior of these. The eight efferent vessels 

 unite in pairs to form fonr epibranchial arteries (epi.). The 



rposl.cctr 



l.posl.car 



l.posl.carcl 



FIG. 909. CeratodUS forsteri. Diagrammatic view of the heart and main blood-vessels, 

 as seen from the ventral surface, aff. 1, 2, 3, 4, afferent vessels ; 1 br,2br, 3 br, 4 br, position of 

 gills ; c. . conus arteriosus ; <Z. . dorsal aorta ; <?. r. precaval vein ; epi. 1, epi. 2. epi. 3, ?/>!. 4, 

 epibranchial arteries ; hit. art. hyoidean artery ; L /-. r. postcaval vein ; /. ant. car. left 

 anterior carotid artery ; 1. aur. left auricle ; ;. br. v. left brachial vein ; ?. jug. r. left jugular 

 vein ; L post. car. left postei-ior carotid artery ; 1. post. card, left cardinal vein ; I. put art. 

 left pulmonary artery ; ?. sc. i?. left subscapular vein ; r. ant. car. right anterior carotid 

 artery; r. aur. right auricle ; r. br. v. right brachial vein; r. jug. right jugular vein; 

 '/. post. car. right posterior carotid ; r. pul. art. right pulmonary artery ; 7% sc. r. right 

 subscapular vein ; vent, ventricle. (After Baldwin Spencer.) 



latter unite dorsally to form a main trunk, which combines with 

 the corresponding trunk of the opposite side to form the median 

 dorsal aorta (d. .). The head is supplied by carotid branches 

 given off from the first epibranchial (L post. car. and r. post, car.), 

 and from the hyoidean arteries (I. ant. car. and r. ant. car), and 

 the latter also gives off a lingual artery to the tongue. From 



