xiv CONTENTS 



PHYLUM PROTOZOA continued. PAGE 



Class V. Infusoria . 90 



1. Example of the Class Paramcecium caudatum 90 



2. Classification and General Organisation ... 93 

 Systematic Position of the Example. . . 93 

 Further Remarks on the Protozoa 103 



SECTION III 



PHYLUM AND CLASS PORIFEBA [PARAZOA] .... . 106 



1. Example of the Class Sycon gelatinosurn 106 



2. Distinctive Characters and Classification 112 



Systematic Position of the Example .114 



3. General Organisation . . 115 



SECTION IV 



PHYLUM CUSLENTERATA . . 129 



Class I. Hydrozoa 129 



1. Example of the Class Obelia .... .129 



2. General Structure and Classification. . . .141 

 Systematic Position of the Example. . . 143 

 Additional Remarks 166 



Class II. Scyphozoa . .167 



1. Example of the Class Aurelia aurita . .... 167 



2. General Structure and Classification. . . . 175 



Systematic Position of the Example. . . . . . .176 



Additional Remarks 183 



Class III. Actinozoa . .183 



1. Example of the Class Tealia crassicornis . 183 



2. Distinctive Characters and Classification . . . 191 

 Systematic Position of the Example. . . ... 194 



3. General Organisation 194 



Class IV. Ctenophora . . 208 



1. Example of the Class Hormiphora plumosa . ... 208 



2. Distinctive Characters and Classification . . . . .217 

 Systematic Position of the Example. . .218 



3. General Organisation 219 



The Relationships of the Ccelenterata 



Appendix to the Coelenterata The Mesozoa . ... 227 



SECTION V 



PHYLUM PLAT\HELMINTHES 232 



1. Examples of the Phylum . ... . . 233 



i. Planaria or Dendroccelum ........ 233 



ii. Fasciola hepatica 2:'>i> 



iii. Tania soliitm 24:> 



