308 



COMPARATIVE ANATOMY 

 r/3osl.car 



W 



FIG. 247. 



FIG. 248. 



FIG. 247. HEART OF Protopterus annecten*. From the left side, part of the 

 wall of the left atrium being removed. (After Rose.) 



W, fibrous cushion extending into the ventricle ; Si.v, sinus venosus, within 

 which the pulmonary vein (Lv) extends to open into the left auricle by a 

 valvular aperture ; L. Vh and E. Vh, left and right atria ; S.a, septum 

 atriorum ; Co, conus arteriosus. 



FIG. 248. Ceratodus forsteri. DIAGRAMMATIC VIEW OF THE HEART AND MAIX 

 BLOOD VESSELS AS SEEN FROM THE VENTRAL SURFACE. (From Parker and 

 Haswell's Zoology, after Baldwin Spencer. ) 



aff. I, 2, 3, 4, afferent branchial arteries ; I br, 2 br, 3 br, 4 br, position of gills ; 

 c.a, conus arteriosus; d.a, dorsal aorta; d.c, ductus Cuvieri ; epi. I, epi.2, 

 epi.3, epi. 4, efferent branchial arteries ; hy.art, hyoidean artery ; i. v. c, post- 

 caval vein ; l.ant.car, left anterior carotid artery; Laur, left auricle; Lbr.v, 

 left brachial vein; l.juy.v, left jugular vein ; I. post. car, left posterior caro- 

 tid artery ; I. post. card, left posteri or cardinal vein ; l.pul.art, left pulmonary 

 artery ; Lsc.v, 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.puLart, right pulmonary artery ; r.sc.v, 

 right sub- scapular vein ; vent, ventricle. 



begins to be divided into two chambers. In Protopterus this divi- 

 sion is complete, so that two currents of blood, mainly arterial and 



