viii TABLE OF CONTENTS. 



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Class II. Ophiuroidea 337 



Class III. Crinoidea 338 



Sub Class I. Eucrinoidea 342 



Sub Class II. Edrioasteroidsa 342 



Sub Class III. Cystidea 342 



Sub Class IV. Blastoidea 342 



Class IV. Echinoidea 343 



Order I. Palechinoidea 345 



Order II. Cidaridae 345 



Order III. Clypeastroidea 346 



Order IV. Spatangoidea 346 



Class V. Holothuroidea 346 



Order I. Actinopoda 349 



Order II. Paractinopoda 349 



SUMMARY 350 



Phylum VIII. MOU.USCA 351 



Class I. Ampliineura 356 



Sub Class I. Placophora ' . . 356 



Sub Class II. Solenogastres 358 



Class II. Acephala 358 



Order I. Protoconchiae 365 



Order II. Heteroconchiae 367 



Class III. Scaphopoda 369 



Class IV. Gasteropoda 369 



Order I. Prosobranchiata 378 



Order II. Opisthobranchiata 381 



Order III. Pulmonata 383 



Class V. Cephalopoda 384 



Order I. Tetrabranchia 394 



Order II. Dibranchia 394 



SUMMARY - 395 



Phylum IX. ARTHROPODA 398 



Qlass I. Crustacea 408 



Sub Class I. Trilobitae 414 



Sub Class II. Phyllopoda 415 



Order I. Branchiopoda 416 



Order II. Cladocera 417 



Sub Class III. Copepoda 417 



Order I. Eucopepoda 42 1 



Order II. Siphonostomata 422 



Sub Class IV. Ostracoda 422 



Sub Class V. Cirripedia 423 



Order I. Lepadidae 425 



Order II. Balanidae 425 



Order III. Rhizocephala 426 



Sub Class VI. Malacostraca 426 



Legion I. Leptostraca 427 



Legion II. Thoracostraca 427 



Order I. Schizopoda 428 



Order II. Stomatopoda 429 



