xiv CONTENTS 



SECTION IX 



I'M IK 



PHYLUM ECHINODEBMATA . 346 



1. Examples of the Phylum . 346 



i. Arterias rnbens and Anthenea Jiavescens ..... 346 



ii. Strongylocentrotus or Echinus ... .... 363 



iii. Gncnmana or Colochirus . . . . . . . . . 369 



iv. Antedon rosacea .... 373 



2. Distinctive Characters and Classification 377 



Systematic Position of the Examples . . . 380 



3. General Organisation 381 



SECTION X 



PHYLUM ANNULATA 403 



Class I. Chaetopoda 403 



1. Examples of the Class . . . ... 404 



i. Nen'!x diimerilii . . 404 



ii. Lumbricus 417 



2. Distinctive Characters and Classification . . . ' . . 426 

 Systematic Position of the Examples 428 



3. General Organisation 429 



Appendix to Chsetopoda Class Myzostomida . . . . 448 



Class II. Gephyrea 450 



1. Example of the Class Sipuucidus nudus 451 



2. Distinctive Characters and Classification 454 



Systematic Position of the Example 455 



3. General Organisation 455 



Class III. Archi-annelida ... 462 



Class IV. Hirudinea 465 



1. Examples of the Class Hirudo medicinalis and H. quinquestriata 465 



2. Distinctive Characters and Classification 474 



Systematic Position of the Examples 476 



.".. General Organisation 476 



General Remarks on the Annulata 481 



SECTION XI 



PiiYi.ru AuTiiKoi-ohA 484 



Class I. Crustacea 484 



1. Examples of the Class , 484 

 i. Apus or Lepidurus .... 484 



ii. Asiacus JtwviatUis ' 498 



2. Distinctive Characters and Classification . . . 519 

 Systematic Position of the Examples 524 



3. General Organisation . 525 



Appendix to Crustacea Class Trilobita . . 558 



(Mass 11. Onychophora . . 559 



(Mass II I. Myriapoda . . .... 566 



1. Distinctive Characters and Classification 566 



2. General Organisation .... 567 



