SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOLUME 81, NUMBER 3 



MORPHOLOGY AND EVOLUTION OF THE 

 INSECT HEAD AND ITS APPENDAGES 



BY 

 R. E. SNODGRASS 



Bureau of Entomology 



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(Publication 2971) 



CITY OF WASHINGTON 



PUBLISHED BY THE SMITHSONIAN INSTITUTION 



NOVEMBER 20, 1928 



