346 



ZOOLOGY 



SECT. 



the row of neural plates. The neural plates are absent in some 



cases (Chelodina). 



Fig. 985.— Anterior vortebrse of young Crocodile. A. atlas; JEp. axis; IS. intervertebral 

 discs; 0. pro-atlas; Ob. neural ai'phes-; Po. odontoid taone ; Pa. ■ spinous processes; Pt. 

 transverse processes ; S. R.^ R.^ ribS ; s. arch of atlas ; u. median piece of atlas ; WK. centra. 

 (From Wiedersheim's Comparative Anatomy.) 



Fig. 986. — Cistudo lutaria. Skeleton seen from below ; the plastron has been removed and 

 is represented on one side. C. costal plate ; Co. coracoid ; e. entoplastron (episternum); 

 J?p. epiplastron (clavicle?); P. fibula; Fe. femur; ff. humerus; Bi/p. hyoplastron ; Epp', 

 hypoplastron ; Jl. ilium ; Js. ischium ; M. marginal plates ; Nu. nuchal plate ; Pb. pubis ; 

 Pro. procoracoid or process of scapula ; Py. pygal plates ; Jt. radius ; Sc. scapula ; T. tibia ; 

 U. ulna ; Xp. xiphiplastron. (From Zittel.) 



The bony elements of the plastron of the Chelonia are an 

 anterior and median plate, or entoplastron, and four pairs of plates 



