440 



MANUAL OF ZOOLOGY 



SECT. 



In the Chelonia (Fig. 249) the total number of vertebrae 

 is always smaller than in the members of the other orders, 

 The cervical and the caudal are the only regions in which 

 the vertebrae are movable upon one another. The vertebrae 



FIG. 249. Cistudo lutaria. Skeleton seen from below ; the plastron has been 

 removed and is represented on one side. C. costal plate ; Co. coracoid ; e. ento- 

 plastron ; Ep. epiplastron ; F. fibula ; Fe. femur ; H. humerus ; //. ilium ; Js. 

 ischium ; M. marginal plates ; Nu. nuchal plate ; Pl>. pubis ; Pro. procora- 

 coid ; Py. pygal plates; ^.radius; 6V. scapula ; T. tibia; U. ulna. (From 

 Zittel.) 



of the trunk, usually ten in number, are immovably united 

 together. Each of the neural spines, from the second to 

 the ninth inclusively, is expanded into a flat plate, and the 



