CONTENTS xiii 



CHAPTER VII 



PAGE 



PHYLUM PLATYHELMIXTHES . ... 150 



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



2. Class I. Turbellaria 155 



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 Tania, 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 176 



1. Mesozoa 176 



2. Nemertinea 177 



3. Nematomorpha 179 



4. Acanthocephala 180 



5. Chaetognatha 180 



6. Rotifera 181 



7. Bryozoa 183 



8. Phoronidea 185 



9. Brachiopoda 185 



10. Gephyrea ... 186 



CHAPTER X 



PHYLUM ECHINODERMATA . 189 



1. Anatomy and Physiology of the Starfish Asterias . 190 



2. Class I. Asteroidea Starfishes 198 



