XVI CONTENTS 



SECTION IX 



PAGE 



Phylum Echinodeiinitta . . . . . . 375 



1. Example of the Asteroidea — Asteiias nibens or Anthenpii fiavencens. 375 



2. Example of the Echinoidea — Stningijlocentrotns or Echintin . 393 



3. Example of the Holothuroidea — Ciirinnarin or Onldi-Jiiiii.s 401 



4. The Crmoidea — Anffdun ntsuven . . 405 



5. Distinctive Characters and Classification . 410 

 Systematic Position of the Examples . 4] 4 



C. General Organisation . . 415 



SECTION X 



Phylum Annulata . , . . 439 



Class I. Chaetopoda . . 439 



1. Examples of the Class . . 440 

 i. Nei-eix diinnerilii . . . . 440 



ii. Lu'iiibriais . , , 454 



2. Distinctive Characters and Classification 464 

 Systematic Position of the Examples . . 466 



3. General Organisation 467 

 Appendix to the Chagtopoda — Class Myzostomida . 489 



Class II. Gephyrea . . . . . .491 



1. Example of the Class — Sipunculua iiKdns 492 



2. Distinctive Characters and Classification . 495 



3. General Organisation . 496 

 Class III. ArcM-annelida . . 503 

 Class IV. Hirudinea . ... 506 



1. Example of the Class— ifmtdo TOefZ?Vt)!((ii'.s and if. ai(,s/;((iv'.s . 506 



2. Distinctive Characters and Classification . . 515 

 Systematic Position of the Example . 517 



3. General Organisation . . 517 



4. General Remarks on the Annulata 523 



526 



SECTION XI 



Phylxtm Akthkopoua 



Class I. Crustacea 526 



1. Examples of the Class 526 

 i. A2ni.s or Lepidurns 526 



ii. Adacus fluviatilis 539 



2. Distinctive Characters and Classification . 561 

 Systematic Position of the Examples . 569 



3. General Organisation . . 570 

 Affinities and Mutual Relationships . . 602 

 Appendix to Crustacea— Class Trilobita . . 604 



Class II. Onychophora .607 



Class III. Myriapoda ' 614 



1. Distinctive Characters and Classification 614 



2. General Organisation ... _ g^g 



