Contents 



Preface page 9 



Introduction 13 



I. The Protozoans (P/iyliim Protozoa) 16 



II. TJie Sponges {Phylum Porifera) 56 



III. Hydroids, Jellyjishes, Sea Anemones, and Corals (Phylum 



Coelcnterata or Cnldaria) 67 



IV. The Comb Jellies [Phylum Ctenophora) 115 



V. T/ie Flativorms (Phyln/n Platyhelminthes) 119 



VI. Tfie Ribbon Worms (Phylum Nemertea) 129 



VII. A Variety oj Animal Groups 133 



VIII. The Arrozo Worms (Phylum Chaetognatha) 144 



IX. The Acorn Worms (Phylum Hemichordata) 146 



X. The Beard Worms (Phylum PogonopJwra) 148 

 XL ThePhoronids (Phylum Phoroni da) 149 



XII. The Moss Animals (Phylum Bryozoa or Ectoprocta) 150 



XIII. The Lamp Shells (Phylum Brachiopoda) 154 



XIV. Tlie Peanut Worms (Phylum Sipuncnloidca) 156 



XV. The Echiuroids (Phylum Echiuroidea) 157 



XVI. TheMollnsks (Phylum Mollusca) 158 



XVII. The Segmented Worms (Phylum Annelida) 200 



XVIII. The Arthropods (Phylum Arthropoda) 226 



XIX. The Echinoderms (Phylum Ecliinodermata) 254 



XX. The Invertebrate Chordates (Phylum Chordata) 286 

 Bibliography 291 

 Index 293 



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