SECT, xv CLASSIFICATION OF CRUSTACEA 



255 



From the Trilobites, however, we are inclined to 

 deduce at least a part of one important group of 

 modern Crustacea, the Ostracoda. We think it 



Li,m, Ins Ostracoda Cirri. 



Apus Phyllopoda Malacostraca 



Nebalidcc 



Ceratiocaris 



The Crttstacean Annelid 



Proposed genealogy of the Crustacea. It will be seen from the text that though we 

 have here given only one root for the Ostracoda it is probable 



had at least a twofold origin. 



le that they have 



probable that the Crustaceans in question may be 

 deduced both from Trilobites and Phyllopods. The 

 strong likeness between these early forms, especially in 

 their larval stages, now perpetuated in the Ostracoda, 



