XM CONTENTS 



SECTION IX 



PAGE 



PHYLUM ECHINODERMATA .......... 368 



1. Example of the Asteroidea Asterias rubens or Anthcnea flavescens 368 



2. Example of the Echinoidea- -Strong ylocentrotus or Echinus . . 386 



3. Example of the Holothuroidea Cucumaria or Colochirus . . 393 



4. The, Crinoiclea Antedon rosacea .... . 396 



5. Distinctive Characters and Classification . .401 

 Systematic Position of the Examples . . 405 



6. General Organisation ..... 406 



SECTION X 



PHYLUM ANNULATA ... . 429 



Class I. Chtetopoda 429 



1. Examples of the Class . . 430 



i. Nereis dumerilii ....... .430 



ii. Lumbricus ....... 443 



2. Distinctive Characters and Classification . 454 

 Systematic Position of the Examples . . . 455 



3. General Organisation ..... - 457 

 Appendix I. to the Chsetopoda Class Myzostomida . 477 

 Appendix II. to the Chsetopoda Class Echiurida . 479 



Class II. Sipunculoidea 484 



1. Example of the Class Sipunculus nudu's 484 



2. Distinctive Characters ....... 488 



3. General Organisation . . 488 

 Class III. Archi-annelida . .491 

 Class IV. Hirudinea . .494 



1. Example of the Class Hinnla >,n iHcitm/i* and H. australis . 494 



2. Distinctive Characters and Classification ... . 503 

 Systematic Position of the Example .... . 504 



3. General Organisation ....... . 505 



General Remarks on the Annulata ... . 510 



SECTION XI 



PHYLUM ARTHKOPODA ........... 514 



Class I. Crustacea . ... . .514 



1. Examples of the Class . . . . . . . . .514 



i. Apus or Lepidurus . . . . . . . .514 



ii. Astacus fluviatilis .......... 527 



2. Distinctive Characters and Classification ..... 54S 

 Systematic Position of the Examples ...... 555 



15. General Organisation . . . . . . . . . .556 



Affinities and Mutual Relationships ....... 587 



Appendix to Crustacea Class Trilobita ...... 589 



Class 11. Onychophora . . 591 



