CONTENTS 



CHAPTER I 



PAGE 



Methods of Investigation — Geological 1 



CHAPTER n 

 Methods of Investigation — Pal^ontological .... 29 



CHAPTER III 

 The Classification of the Mammalia ...... 50 



CHAPTER IV 

 The Skeleton and Teeth of Mammals 61 



CHAPTER V 

 The Geographical Development of the Americas in Cenozoic 



Times 99 



CHAPTER VI 

 The Geographical Distribution op Mammals 135 



CHAPTER VII 



The Successive Mammalian Faunas of North and South America 192 



CHAPTER Vin 

 History of the Perissodactyla 288 



CHAPTER IX 

 History of the Artiodactyla 358 



CHAPTER X 



History of the Proboscidea 422 



xiii 



