CONTENTS xiii 

 CHAPTER VII 



PAGE 



PHYLUM PLATYHELMINTHES 150 



1. A Fresh-water Flatworm Planaria . . . .150 



2. Class I. Turbellaria ice 



3. Class II. Trematoda . 157 



a, The Liver Fluke Fasciola hepatica, 157; b, Tre- 

 matoda in General, 161. 



4. Class III. Cestoda 163 



a. The Tapeworm Tcenia, 163 ; b, Cestoda in General, 

 165. 



5. Fhtworms in General .166 



CHAPTER VIII 



PHYLUM NEMATHELMINTHES 169 



1. A Parasitic Round Worm Ascaris lumbricoides . .169 



2. Nemathelminthes in General 173 



CHAPTER IX 



INVERTEBRATES OF MORE OR LESS UNCERTAIN SYSTEMATIC 



POSITION I7 6 



1. Mesozoa I7 6 



2. Nemertinea 177 



3. Nematomorpha 179 



4. Acanthocephala 180 



5. Chaetognatha 180 



6. Rotifera X 8i 



7. Bryozoa ^3 



8. Phoronidea 185 



9. Brachiopoda . 185 



10. Gephyrea . . .186 



CHAPTER X 



PHYLUM ECHINODERMATA . 189 



i. Anatomy and Physiology of the Starfish Asterias . 190 



3. Class I. Asteroidea Starfishes . 198 



