SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOLUME 81, NUMBER 3 



MORPHOLOGY AND EVOLUTION OF THE 

 INSECT HEAD AND ITS APPENDAGES 



BY 



R. E. SNODGRASS 

 Bureau of Entomology 



(Publication 2971) 



CITY OF WASHINGTON 

 PUBLISHED BY THE SMITHSONIAN INSTITUTION 



NOVEMBER 20, 1928 



