Till", AUTHOR wishes to acknowledge witli thanks 

 the \ery valuable assistaiiee £>iven him bv the 

 t"olh)winii,' i>cntKiU('ii — assistaiiee which inach' this 

 work possible: 



To Du. A\'ii.i.i\.M 1>aum;s, Decatur, 111., wlio uiicouditioually 

 turned ovci- to tlic authoi- liis entire entoniolofrical resources; 

 collection, witii specimens carefully matched to tiie types 

 of almost every species considered, i)y liimself, I)h. J. Mc- 

 Di'xxoi'Gii, "and Sir Gkorc.k llAJii>sf)x; laboratory; per- 

 sonal notes; and unpuiilislied maniiscrij)ts. Unless other- 

 wise stated, all specimens cicamined are in tlie Barnes Col- 

 lection. 



To Uii. A. A\'. LixDSKv, Decatur, 111., for iiis iiersonal assist- 

 ance aiul suggestions. 



To I)u. AV. T. ^I. FouHKs, of Cornell I'nix'crsity, for criticisms 

 and suggestions. 



To Mn. George P. Exuei.mardt and Mr. Jacois Doll, for com- 

 parisons with ty])es in the Brooklyn Museum, and the loan 

 and donation of specimens. 



To Mr. J. M. "VVallis^ "Winnipeg, Canada, for the loan of 

 Northwestern material . 



To Du. II. G. Dyar, Dr. Hexry Skixxer, Dr. Charles Beck- 

 wiTiij Dr. "W. p. Alexander, and Mr. .Jacob Doll for lists 

 of types in their cliarge; and 



To Dr. Ja:mes G. Needhaji, of Cornell University, under whose 

 kind jurisdiction this paper was written. 



