CONTENTS 



CHAPTER PAGE 



I. GENERAL INTRODUCTORY - - I 



II. CLASSIFICATION - - - "14 



III. GEOLOGICAL HISTORY - - - "44 



IV. PRESENT HISTORY AND DISTRIBUTION - - 5 1 

 V. FOOD, HABITS, ETC. - - - - 67 



VI. REPRODUCTION - - - - -87 



VII. EVOLUTION - - - - - IOO 



VIII. INSTINCT, INTELLIGENCE, AND USES - " T 37 



INDEX 



145 



