Chapter II: Preface: iii

SCHEME OF THE CLASSIFICATION ADOPTED IN THIS BOOK ix

CHAPTER I

INTRODUCTORY 1

CHAPTER II

STRUCTURE AND PRESENT DISTRIBUTION OF THE MAMMALIA 5

CHAPTER III

THE POSSIBLE FORERUNNERS OF THE MAMMALIA 90

CHAPTER IV

THE DAWN OF MAMMALIAN LIFE 96

CHAPTER V

THE EXISTING ORDERS OF MAMMALS: PROTOTHERIA--MONOTREMATA 105

CHAPTER VI

INTRODUCTION TO THE SUB-CLASS EUTHERIA 116

CHAPTER VII

EUTHERIA--MARSUPIALIA 122
{vi}

CHAPTER VIII

EDENTATA--GANODONTA 161

CHAPTER IX

UNGULATA--CONDYLARTHRA--AMBLYPODA--ANCYLOPODA--TYPOTHERIA--
TOXODONTIA--PROBOSCIDEA--HYRACOIDEA 195

CHAPTER X

UNGULATA (_continued_)--PERISSODACTYLA (ODD-TOED UNGULATES)--
LITOPTERNA 235

CHAPTER XI

UNGULATA (_continued_)--ARTIODACTYLA (EVEN-TOED UNGULATES)--SIRENIA 269

CHAPTER XII

CETACEA--WHALES AND DOLPHINS 339

CHAPTER XIII

CARNIVORA--FISSIPEDIA 386

CHAPTER XIV

CARNIVORA (_continued_)--PINNIPEDIA (SEALS AND WALRUSES)--CREODONTA 446

CHAPTER XV

RODENTIA--TILLODONTIA 458

CHAPTER XVI

INSECTIVORA--CHIROPTERA 508