VERTEBEATA 



117 



uncommon in the Eocene of America, with one form in the 

 Eocene of Switzerland. Later than that age thej' are un- 

 known. (Fig. 53). The Creodonta are probably the an- 

 cestors of the Carnivora and Insectivora, and the Tillodonta 

 of the Glires. The Pantotheria are ancestors of the Creo- 

 donta. The time relations of the Bunotherian orders are 

 expressed in the following table : 



Plistocene 



Neocene 



Eocene 



Cretacic 



Jurassic 



Triassic 



Carbonic 



Devonic 



Siluric 



Pantotbeiia 



CreoiloMta 



lusectivora Tillodoote 



I 



Ordovicic . 



Cambric 



Huronic . . . . 



True Caknivora are definitely known from the beginning 

 of the Neocene, and it is probable that they already existed 



