86 



WATER REPTILES OF THE PAST AND PRESENT 



degree, some digits of some species having as many as twenty-four 

 bones, a larger number than has been observed in any other air- 

 breathing vertebrate. 



Fig. 39. — Pectoral girdle (in part) and 

 front paddles of Elasmosaurus (after Riggs) : 

 sc, scapida; h, humerus; cor, coracoid; r, 

 radius; u, ulna. 



In Fig. 38 on p. 85 are shown two paddles, the front and 

 hind paddles of a single individual of a very specialized ple- 

 siosaur from the Upper Cretaceous of Kansas (Trinacromerum) . 

 The long arm and thigh bones are followed by remarkably short and 



