CONTENTS 



PAGE 



Subphylum 4. Bryozoa 245 



Class 1. Entoprocta 246 



Class 2. Ectoprocta 248 



Subphylum 5. Brachiopoda 264 



Subphylum 6. Phoronidea 270 



Subphylum 7. Chaetognatha 271 



Subphylum 8. Sipunculoidea 272 



Class 1. Sipunculida 273 



Class 2. Priapulida 276 



PHYLUM 4. ANNELIDA 277 



Class 1. Archiannelida 280 



Class 2. Chaetopoda 281 



Class 3. Hirudinea 315 



Class 4. Myzostomida 321 



PHYLUM 5. ARTHROPODA 323 



Class 1. Crustacea 326 



Class 2. Arachnoidea 400 



Class 3. Tracheata 461 



PHYLUM 6. MOLLUSCA 478 



Class 1. Amphineura 482 



Class 2. Scaphopoda 490 



Class 3. Gastropoda 492 



Class 4. Pelecypoda 563 



Class 5. Cephalopoda 602 



PHYLUM 7. ECHINODERMATA 614 



Class 1. Crinoidea 619 



Class 2. Asteroidea 623 



Class 3. Ophiuroidea 633 



Class 4. Echinoidea 638 



Class 5. Holothurioidea 646 



PHYLUM 8. CHORDATA 652 



Subphylum 1. Enteropneusta 652 



Subphylum 2. Tunicata 655 



Class 1. Larvacea 657 



Class 2. Thaliacea * 660 



Class 3. Ascidiacea 663 



Subphylum 3. Leptocardia 671 



LIST OF AUTHORS 675 



GLOSSARY 693 



INDEX . 705 



