No. 446.] RECLASSIFICA TION OF THE RFFTIIJA. 



the persistence in certain forms of a suture l)ct\vccii tlu 

 and procoracoid. 



This line also became very highly specialized, and d: 

 the Trias. 



6. Order Choristodera Cope. 



These amphibious animals, found thus far only in the Creta- 

 ceous and in the Lower Eocene, represent a sharply defined 

 division with a greatly elongated gavialoid rostrum, teeth acro- 

 dont and internally folded, dorsal ribs two-headed. They include 

 the American Champsosaurus and the European Simoidosaurus ; 

 the latter being distinguished by more distinct adaptation to 

 aquatic life were made the type of the order Simoedosauria by 

 Dollo. The analogies are with the Proganosauria and the aquatic 

 true Rhynchocephalia, but there are no phylogenetic relation- 

 ships with these forms. 



