THE REIGN OF MAMMALS. 



2oy 



of the world in which these deposits are known to exist. 

 Indeed the recent discoveries in America and in the east of 

 Europe have almost thrown into the shade those researches of 

 Cuvier in the Paris basin which first brought this important 

 fact to light. The Eocene mammals, like the Carboniferous 



Via. i66. — Jaw of Dromathct ium y/z/fj^/*^ (Emmons). From the Trias of North Carohna. 



amphibians, the Mesozoic reptiles, and the Cretaceous forests, 

 appear to spring full-grown from the earth, and this at nearly 

 the same time in every part of the northern hemisphere. It 

 has been suggested that they may have come in gradually 



Fig. 167. — Myrmecobius fasciatus. A modern Australian marsupial, allied to Mesozoic 



species. 



without our knowledge in the Cretaceous period ; but if so, 

 we should have found some of their remains along with those 

 of the Upper Cretaceous plants. But the prevalence of the 

 great reptiles up to the close of the Cretaceous would seem to 

 ender the co-existence of large mammals unlikely. It has 



p 



