TABLE OF CONTENTS. vii 



PAGE 



Class II. Scyphozoa 245 



Order I. Stauromeduss 250 



Order II. Peromedusae 250 



Order III. Cubomedusae 2 so 



Order IV. Discomeduss 250 



Class III. Anthozoa 251 



Order I. Tetracoralla 25S 



Order II. Octocoralla 258 



Order III. Hexacoralla 259 



Class IV. Ctenophora 261 



Summary 265 



Phylum IV. PlaThelminthES 267 



Class I. Turbellaria 268 



Order I. Polycladidea 271 



Order II. Tricladidea 271 



Order III. Rhabdoccelida 271 



Class II. Trematoda 271 



Order I. Polystomiae 273 



Order II. Distomis 274 



Class III. Cestoda 278 



Class IV. Nemertini 289 



Summary 292 



Phylum V. RoTIFERA 293 



Phylum VI. CcElhELMINThES 295 



Class I. Chaetognathi 296 



Class II. Nemathelminthes 298 



Order I. Nematoda 298 



Order II. Gordiacea 304 



Order III. Acanthocephala 304 



Class III. Annelida 305 



Sub Class I. Chaetopoda 306 



Order I. Polychaetae 311 



Order II. Oligochaetae 314 



Sub Class II. Gephyraa 316 



Order I. Chaetiferi 31 y 



Order II. Inermes 317 



Order III. Priapuloidea 317 



Sub Class III. Hirudinei 318 



Order I. Gnathobdellidae 321 



Order II. Rhynchobdellidae 321 



Class IV. Polyzoa 321 



Sub Class I. Entoprocta 321 



Sub Class II. Ectoprocta 322 



Class V. Phoronida 325 



Class VI. Brachiopoda 325 



Order I. Ecardines 328 



Order II. Testicardines 328 



Summary 328 



Phylum VII. EchinodERMA 329 



Class I. Asteroidea 333 



