vi CONTENTS 



PHYLUM MOLLUSCA 



PAGE 



A Fresh-water Clam {Anodonta or Unio) 72 



The Oyster 81 



The Hard-shell Clam (KiE^£/5 3f£/?CiiiV^/i/^) 85 



A Land Snail 93 



A Squid {Loligo peali) 103 



PHYLUM ECHINODERMATA 



A Starfish 113 



A Sea Urchin 119 



A Sea Cucumber 124 



PHYLUM CCELENTERATA 



Hydra 127 



A Tubularian Hydromedusan (Pennaria) 131 



A Campanularlan Hydromedusan {Obeli a or Campanularia) . . 136 



A Medusa (Gonionemus) 141 



A Sea Anemone (Metridium) 143 



PHYLUM PORIFERA 



A Sponge (Grantia) 145 



PHYLUM PROTOZOA 



Paramecium 148 



Vorticella 152 



A Flagellate (Euglena viridis) 156 



Amoeba 158 



PHYLUM CHORDATA 



SUBPHYLUM TUNICATA 



A Simple Ascidian (Molgula) 160 



