MANUAL 



FAMILIES AND GENEEA 



]sroRTH American Diptera 



SECOND EDITION 



REWRITTEN AND ENLARGED 



SAMUEL W;' WILLISTON, M.D., Ph.D. (Yale) 



PROFKSSOR OF PALEONTOLOGY AND ANATOMY UNIVERSITY OF KANSAS 



•"%y\ 



Vi« 



NEW HAVEN 

 JAMES T. HATHAWAY 



297 CROWN ST. NEAR YALE COLLEGE 



18 0G 



