308 



Z./7t; 



COMPARATIVE ANATOMY 



rposLcar 

 j:aftl.can 



l.poaij;ar lant/iar 



Si^, 



Fig. 247. 



-ptcL.-vein 



— l.post.card 



l.f.C 



<i.a. 



Fig. 248. 



Fig. 247. — Heart of Proiopterus annectens. From the left side, part of the 

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



W, fibrous cushion extending into the ventricle ; Si. r, 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. — Ceratodns forsieri. Diagrammatic A''iew of the Heart .and JIain 

 Blood Vessels as seen from the Ventral Surf.ace. (From Parker and 

 Haswell's Zoology, after Baldwin Spencer. ) 



1, 2, .3, 4, afferent branchial arteries ; \hr, 2 br, 3 hr, 4 br, position of gills ; 

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

 epi.3, I'piA, efferent branchial arteries ; hy.arf, hyoidean artery ; i. r. c, post- 

 caval vein ; Latif.car, left anterior carotid artery; Lam; left auricle; l.br.v, 

 left brachial vein; /.jin/.r, left jugular vein ; l.post.car, left posterior caro- 

 tid artery; /.^os^.ca^T^, left posteriorcardinal vein ; l.pui.art, \eit pulmonary 

 artery; l.sc.v, left sub -scapular vein ; r. aw/, rar, right anterior carotid artery ; 

 r.anr, right auricle ; r.br.v, right brachial vein ; r.7 »</.«, right jugular vein ; 

 r.post.rar, right posterior carotid ; r.pul.art, right pulmonary artery ; r.sc.v, 

 right sub-scapular vein ; rent, ventricle. 



«/• 



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

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



