The Skeleton 



n 



III. The Ribs and Sternum. 



The Cervical Ribs. As noted above, all of the 

 cervical vertebrae possess ribs. The first rib, 



Fig. 25. Hyoids of an Alligator {Caiman lalirostris) 

 (to the left) and of a Green Turtle {Chelone midas) (to 

 THE right). Xf. (Brit. Mus.) (After Reynolds.) 



The cartilaginous portions are dotted. 



1. basilingual plate or body of 3. first branchial arch (anterior 



the hyoid. comu). 



2. hyoid arch.^ 4. second branchial arch (pos- 



terior cornu). 



attached to the atlas, consists of a single, long blade 

 projecting backward at an acute angle (Fig. 17, 8) 

 as far as the middle of the fourth vertebra. As 

 described above it articulates with the atlas at but 

 one place. All of the other cervical ribs have two 

 articular surfaces, a tuberculum and a capitulum, 



