CONTENTS. 



CHAPTER I. 



PAGE 



ON CLASSIFICATION IN GENERAL ...... 1 



CHAPTER II. 



THE CHARACTERS OF THE CLASSES OF THE INVERTEBRATA . . 6 



CHAPTER in. 



THE CHARACTERS OF THE CLASSES OF THE VERTEBRATA . . 59 



CHAPTER IV. 



ON THE ARRANGEMENT OF THE CLASSES INTO LARGER GROUPS . 75 



CHAPTER V. 



THE SUBCLASSES AND ORDERS INTO WHICH THE CLASSES OF THE 



VERTEBRATA ARE DIVISIBLE ...... 87 



CHAPTER VI. 



THE ORDERS INTO WHICH THE CLASSES OF THE INVERTEBRATA ARE 



DIVISIBLE . 115 



GLOSSARY 131 





& 



Yv, 



