XIII 



PHYLUM CHORDATA 



235 



given off from the first epibranchial (I. ant. car. and r. ant. car.y 

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

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

 the last (fourth) epibranchial artery arises the pulmonary artery 

 (I. pul. art. and r. pul. art.), carrying blood to the lung. 



rposl.car 



l.poal.cur 



ptil.-vein, 

 l.posl.ca,rd> 



1.1/.C 



d.ci, 



FIG. 859. Ceratodus Forsteri. Diagrammatic view of the heart and main blood-vessel,, 

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

 gills ; c. a. conns arteriosus ; d. a. dorsal aorta ; d. c. ductus Cuvieri ; epi. 1, epi. 2, epi. 3, epi. 4, 

 efferent branchial arteries ; hy. art. hyoidean artery ; i, v, c, post-caval vein ; I. ant. car. left 

 anterior carotid artery ; 1. aur. left auricle ; 1. br. v. left branchial vein ; I. jug. v. left jugular 

 vein ; I. post. car. left posterior carotid artery ; I. post. card, left posterior cardinal vein 

 1. -pul. art. left pulmonary artery ; 1. sc. %. left sub-scapular vein ; r. ant. car. right anterior 

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

 vein ; r. post. car. right posterior carotid ; r. pul. art. right pulmonary artery ; r. sc. r. 

 right sub-scapular vein ; vent, ventricle. (After Baldwin Spencer.) 



There are two ductus Cuvieri (d. c.), as in the Dog-fish (p. 146). 

 The right ductus is formed by the union of jugular (1. jug. v. and 

 r. jug. v.), brachial (1. br. v. and r. br. v.), and subscapular veins- 

 (1. sc. v. and r. sc. v.). The left receives in addition a left posterior 

 cardinal vein (I. post. card.). A large lateral cutaneous vein running 

 superficially along the side of the body opens into the subscapular.. 



