viii CONTENTS. 



INVERTEBRATES. 

 CHAPTER VII. 



PAGE 



PROTOZOA ..... 88 



CHAPTER VIII. 

 SPONGES. ....... 121 



CHAPTER IX. 



CCELENTERA .... 133 



CHAPTER X. 

 UNSEGMENTED "WORMS" ..... 169 



CHAPTER XI. 

 ANNELIDS ..... 196 



CHAPTER XII. 



ECHINODERMS ...... 239 



CHAPTER XIII. 

 ARTHROPODA ....... 265 



CHAPTER XIV. 



ONYCHOPHORA OR PROTOTRACHEATA, MYRIOPODA, AND 



INSECTA ....... 302 



CHAPTER XV. 

 ARACHNOIDEA AND PAL.^OSTRACA .... 347 



CHAPTER XVI. 

 MOLLUSCS ....... 364 



