SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOLUME 97. NUMBER 6 



EVOLUTION OF THE ANNELIDA, ONYCHOPHORA, 

 AND ARTHROPODA 



BY 

 R. E. SNODGRASS 



Bureau of Entomology and Plant Quarantine 

 U. S. Department of Agriculture 



(Publication 3483) 



CITY OF WASHINGTON 



PUBLISHED BY THE SMITHSONIAN INSTITUTION 



AUGUST 23, 193 8 



