Vlll CONTENTS. 



PAGE 



CHAPTER X. 

 Insects : their Ears and Eyes .... . . 158 



CHAPTER XL 

 Crabs and Shrimps 171 



CHAPTER XII. 

 Barnacles .191 



CHAPTER XIII. 

 Spiders and Mites 203 



CHAPTER XIV. 

 Wheel-bearers 223 



CHAPTER XV. 

 Worms 258 



CHAPTER XTI. 

 Sea-urchins and Sea-cucumbers 276 



CHAPTER XVH. 

 Jelly-fishes . 307 



CHAPTER xvrn. 

 Zoophytes . 325 



CHAPTER XIX. 

 Sea-anemones: their Weapons 355 



CHAPTER XX. 

 Protozoa and Sponges 376 



CHAPTER XXI. 

 Infusoria 389 



