232 



DINOSAUR* OF NORTH AMERICA. 



AFFINITIES WITH BELODONTIA. 



Another group of extinct reptiles, which may be termed the Belo- 

 dontia, were considered in the same paper as allies of the Dinosauria. 

 They are known from the Trias of Europe and America, and the type 

 genus, Belodon, has been investigated by many anatomists, who all 

 appear to have regarded it as a crocodilian, an opinion that in the 

 light of our present knowledge may fairly be questioned. 



Fig. 57.— Diagram of left liiuil limb of Alligator missisnippiensis Gray ; seen from the left; in position 

 fur comparison -with dinosaurs. One-fourth natural size. 

 Fig. 58— Diagram of left hind limb of A'elosaurusferratvs; in same position. One-half natural size. 



AFFINITIES WITH CEOCODILIA. 



The relations of these various groups to the true crocodiles on the 

 one hand and to dinosaurs on the other is much too broad a subject to 

 be introduced here, but attention may at least be called to some poiuts 

 of resemblance between the dinosaurs and these supposed crocodilian 

 forms that seem to indicate genetic affinities. 



