viii CONTENTS. 
CHAPTER IX. 
THE CHARAUTERS OF GENERA . . 5 c . . - 126 
CHAPTER X. 
SPECIES AND BREEDS 4 ‘ . Ci a ‘ « 184 
CHAPTER XI. 
FORMATION OF CORAL REEFS . * F : . a » 148 
CHAPTER XII. 
AGE OF CORAL REEFS AS SHOWING PERMANENCE OF SPECIES 175 
CHAPTER XIII. 
HOMOLOGIES . . . o D z ‘ ¢ + 201 
CHAPTER XIV. 
ALTERNATE GENERATIONS : : . . is - 233 
CHAPTER XV. 
THE OVARIAN EGG . 7 . A 5 5 : + 269 
CHAPTER XVI. 
EMBRYOLOGY AND CLASSIFICATION . . . 4 . » 296 
