CONTENTS. 



CHAPTER I. 



PAGE 

 EXPLANATORY AND INTRODUCTORY . 1 



THE FIRST OR ANCIENT EPOCH. 



CHAPTER II. 



THE PERIOD ANTECEDENT TO THE INTRODUCTION OF LIFE 



THE DEPOSIT OF NON-FOSSILIFEROUS ROCKS . . 15 



CHAPTER III. 



THE PERIOD OF THE EXISTENCE OF INVERTEBRATED ANI- 

 MALS AS THE MOST HIGHLY ORGANIZED INHABITANTS OF 

 THE SEA THE SILURIAN ROCKS . , .23 



CHAPTER IV. 



THE INTRODUCTION OF FISHES, THE CHARACTERISTIC ANIMALS 

 OF THE SECOND FOSSILIFEROUS PERIOD THE DEVONIAN 

 OR OLD RED SANDSTONE SYSTEM OF FORMATIONS . . 52 



CHAPTER V. 



THE APPEARANCE OF LAND AND THE INTRODUCTION OF LAND 



VEGETABLES THE CARBONIFEROUS SYSTEM 73 



