599 



aa, 



Fig 462. Diagrams to show the development of the embryonic arterial arches 



in a selachian.. — From Goodrich, Studies on the Structure and Development oj 

 Vertebrates, 1930. Macmillan, London. 



and bra .\fferent branchial ; ae, and aef, anterior efferent ; ah, and ha, afferent of hyoid bar ; amd 

 and mda, afferent of mandibular bar ; aps, afferent pseudobranchial anastomosis ; at auricle ; brf. 

 and bre 4, epibranchial ; ba, basal artery ; c, conus ; ca, cardiac ; car cceliac ; cf cerebral :*•«• /'r^'; 

 commissural; da, median dorsal aorta; dc, ductus Cuvier.; ^./>/. '*«^'7"VP=^'''".'^^^"''"^" ".t\' =■ f/' f' 

 lamella • h, hyoid bar ; hbr, hvpobranchial ; he, efferent of hyoid bar ; /if hep.itic veins . tc, inUrn.i] 

 carotid -Ida, left lateral dorsal aorta ; md, mandibular bar ; op. optic ; oph, ophthalmic ; <?'• ^^rl'^t-'' • 

 Pe and pef, posterior efferent ; ps, mandibular pseudobranch ; rb, posterior cerebral ; rlda, right later^ 

 doial aort?; sc, sinus cephalicis ; sd. subclavian; t- ventricle ; fa. ventral aorta; 1-6. primitive 

 arches ; I-V, branchial gill slits ; S, spiracle. 



