30 



VERTEBRATA OF THE TERTIAEY. 



y?. Peculiar. 



Champsosaurus. 



Compsemys. 



Myhdaphus. 



Sables de Bracheux and Con- 



GLOMEEAT DE CeENY. 



Champsosaurus. 

 Compsemys. 

 Myledaphus. 

 Scapherpeton. 



Laeamie. 



y. Ceetaceous. 



Pakeoscincus. 



Dysganus. 



Monoclonius. 



Diclonius. 



Cionodon. 



Lcelaps. 



Auhhjsodon. 



If the Conglomerate of Cemy be the same horizon as the Conglomerate 

 of Meudon, we must add Coryphodon to the upper left-hand column, and 

 probably Gastornis also. The i*esult is clear that the French and American 

 formations together bridge most completely the interval between the Cre- 

 taceous and Tertiary series, as has been anticipated by Hayden, in America, 

 on geological grounds. It is also evident that another formation must be 

 added to the series already recognized in France, viz, the Laramie or Post- 

 Cretaceous. Tliis will be defined as the beds of the genera Champsosaurus 

 and Myhdaphus. In France, the presence of mammalia will characterize 

 the formation as a subdivision, for which it is probable that the name 

 Thanetian must be retained ; while to the American division, which is 

 characterized by tlie presence of Dinosatiria, the name of Laramie beds has 

 been given. 



In arranging the Laramie Group, its necessary position is between 

 Tertiary and Cretaceous, but on the Cretaceous side of the boundary, if 

 we retain tliose grand divisions, which it appears to me to be desirable to 

 do. The reasons for retaining it in the Cretaceous are two, viz: (1) because 



