Contents 



FOREWORD . vii 



INTRODUCTION l 



CHAPTER I The mechanics of swimming ... 9 



CHAPTER II Aquatic mammals ..... 24 



CHAPTER III External features ..... 48 



CHAPTER IV The Senses .... .61 



Visual ...... 61 



Acoustic ....... 68 



Olfactory ...... 74 



CHAPTER V Mouth and nose ..... 76 



Mouth 76 



Teeth 82 



Nose 87 



Adipose cushion . . . . . 103 



CHAPTER VI The skull 107 



CHAPTER VII The neck 138 



CHAPTER VIII The trunk 153 



CHAPTER IX The tail 183 



CHAPTER X The pectoral limb ..... 206 



CHAPTER XI The pelvic limb 268 



CHAPTER XII Other soft parts and physiological features . 310 



LITERATURE CITED ....... 326 



INDEX 333 



IX 



