e NORTH AMERICAN DIPTERA 



It is my hope that those who may discover errors or omissions may 

 be kind enough to call them to my attention, indicating the manner in 

 which the corrections may be made. Owing to the numerous footnotes 

 it has not been possible to indicate the genera which have been included 

 from description only. Such genera naturally weaken a key as it is 

 impossible to use characters which may be available for a more suitable 

 arrangement. Any specimens representing genera improperly placed, 

 or not common, would be most greatly valued by the author. 



Finally I wish to express my unbounded admiration for the late 

 Samuel Wendell Williston. To him I owe, as do very many others, an 

 everlasting gratitude for his kindly encouragement, while he lived, and 

 real inspiration from his printed works. I know of no Dipterologist 

 who has so clearly set forth the facts or who has been so great an 

 inspiration to others. And as a slight token of my appreciation I re- 

 spectfully dedicate this book to his memory. 



C. H. CURRAN, 



American Museum of Natural History, 

 New York City, 1933. 



