LIST OF ILLUSTRATIONS. 



PAGE 



Virgnlaria mirabiUs . . .108 



Pleurobrachia Ill 



Diagrammatic sections of 



Pleurobrachia . . . .112 

 Structure of Coral Reefs .116 

 Morphology of Echinoidea 125 

 Larva of Echinus. Diagram 



of Echinus 127 



Ur aster rubens . . . .129 

 Ophiocoma neglecta . . .132 

 Ehizocrinus Lofotensis . . 134 

 Echinosphcerites aurantium 135 

 Cucumaria communis . .137 

 Morphology of Tceniada . 145 



Trematoda 148 



Morphology of Turbellaria 149 

 Echinorhynchus gigas . .151 

 Stephanoceros Eichornii . 155 

 Diagrammatic section of an 



Annelide 161 



Sanguisuga officinalis . .162 



Serpula 165 



Nereis 167 



Diagram of the somite of a 



Crustacean 174 



Morphology of the Lobster 175 

 Morphology of Cirripedia . 180 

 Daphnia pulex . . . .184 

 Morphology of Trilobites . 186 

 Limulus Polyphemus . .188 

 Pterygotus Anglicus . . .188 

 Talitrus locusta . . . .190 

 Spider-crab (Maia) . . .194 

 Morphology of Arachnida . 199 

 Tetranychus tclarius . . 202 

 Theridion riparium . . . 205 



