408 



CHELONIA. 



therefore incomplete. The columella auris is bony and reaches 

 from the fenestra ovalis to a small cartilage in the tym- 

 panum. In the mandible, the two dentaries are fused, as in 

 birds, and five pairs of other bones are present (articular, angular, 



Fig. 229. — Skeleton of Emys europaea, in ventral view vritli plastron turned to one side 

 (from Claus). B plastron ; C costal plates ; CI epiplastron (clavicle) ; Co coracoid; F fibula ; 

 Fe femur ; H humerus ; J d entoplastron (interclavicle) ; Jl ilium ; Js ischium ; M marginal 

 plates ; Nu nuchal, Py pygal plate ; Pb pubis ; Pco precoracoid (acromial process) ; R 

 radius ; Sc scapula ; T tibia ; U ulna ; V neural plates. 



Burangular, splenial, and coronoid). The hyoid consists of a 

 cartilaginous basihngual plate and of two pairs of ossified comua, 

 which have no direct connection with the skull. 



Teeth are completely absent, but the jaws, both upper and 



