The Inner (Alimentary) Tube and Its Respiratory Derivatives 5' 



Fig. 56. Diagram of gill-clefts in (A) elasmobranchs and (B) teleosts. (A', B') 

 A single gill of each, (a) Artery; (ba) branchial arch; (br) branchial ray; (d) demi- 

 branchs; (gc) atrial chamber; (gr) gill raker; (o) operculum; (oe) esophagus: (oo) 

 opercular opening; (s) spiracle (in .4); (s) septum (in A') (v) veins. (Courtesy, 

 Kingsley: "Comparative Anatomy of Vertebrates," Philadelphia, The Blakiston 

 Company.) 



Fig. 57. Diagram of the relations of external and internal gills in the anuran 

 (frog or toad) tadpole, (ab, eb) Afferent and efferent branchial arteries; (h) heart; 

 (o) ear cavity; (ph) pharynx; (ra) radix aortae. (After Maurer. Courtesy. Kingsley: 

 "Comparative Anatomy of Vertebrates," Philadelphia. The Blakiston Company.) 



