IV. VERTEBRATA: REPTILIA. 



responding bones of the opposite side by a double symphysis. In the 

 shoulder girdle scapula and coracoid alone are constant, a clavicle occur- 



7.H 



FlG. 573. Viscera of Alligator (from Wiedershcim). ED, rectum; 77, heart; L, 

 liver; Lg, lung; M, stomach; MD, intestine; Oe, oesophagus; P, pylorus; 7>, trachea; 

 ZB, body of hyoid; ZH, its cornua; *, perforations of hyoid. 



ring in turtles and lizards, in the latter an episternum (fig. 521) as well. 

 Of considerable systematic importance is the position of the ankle joint. 



