MANUAL 



OF 



North American Diptera 



BY 



SAMUEL W. WILLISTON 



Third Edition 



JUlnstratrfc 





NEW HAVEN <$< 'W <^* 



v6 «$w *r 



JAMES T. HATHAWAY X^ O V 



37 CROWN ST. NEAR YALE COLLEGE -X* feV /"V 



4F& 



1 908 



