x CONTENTS 



THE CENOZOIC ERA 



CHAPTER PAGE 



XXVI. THE EOCENE AND OLIGOCENE PERIODS 



FORMATIONS AND PHYSICAL HISTORY 556 



LIFE 565 



OLIGOCENE FORMATIONS 573 



OLIGOCENE LIFE 578 



XXVII. THE MIOCENE PERIOD 



FORMATIONS AND PHYSICAL HISTORY 581 



LIFE 591 



XXVIII. THE PLIOCENE PERIOD 



FORMATIONS AND PHYSICAL HISTORY 599 



LIFE 608 



XXIX. THE PLEISTOCENE OR GLACIAL PERIOD 



FORMATIONS AND PHYSICAL HISTORY 613 



CAUSE OF GLACIAL CLIMATE 648 



LIFE 663 



XXX. THE HUMAN OR PRESENT PERIOD 



FORMATIONS 677 



LIFE 678 



APPENDIX 



REFERENCE TABLE OF THE PRINCIPAL GROUPS OF PLANTS . 685 

 REFERENCE TABLE OF THE PRINCIPAL GROUPS OF ANIMALS 686 



