A EEVISION OF THE NORTH AMERICAN SPECIES OF 

 THE GENUS •ARGYRA MACQUART, TWO -WINGED 

 FLIES OF THE FAMILY DOLICHOPODIDAE 



By M. C. Vax Duzee 



Of Buffalo, Neto York 



The present paper is a review of the North American species of 

 the genus Argyra and contains descriptions of 26 new species as 

 well as a more or less complete redescriptions of the species pre- 

 viously described. 



The association of the females with the males is in some cases 

 subject to doubt; but with the large amount of material in my 

 hands I have felt little uncertainty in placing them. 



Measurements of the tarsal joints are given for all the species; 

 these were made with an eyepiece micrometer, and each unit is very 

 nearly one-fiftieth of a millimeter. 



I am greatly indebted to Dr. J. M. Aldrich for the loan of his 

 material (since donated to the National Museum) ; to C. W. Johnson, 

 who sent me his material and that of the Boston Society of Natural 

 History, and started me at work on the genus : also to C. H. Curran, 

 of the Entomological Branch, Ottawa, Canada, who sent me three 

 very interesting forms, new to me. 



Genus ARGYRA Macquart 



Argyra Macquart, Hist. Nat. Dipt., vol. 1, 1S34, p. 4.56. — Loew, Smiths. 



Misc. Colls., No. 171, 1864, pp. 123-132.— Becker, Nova Acta, vol. 104, 



pt. 2, 1918, pp. 61-74. 

 Lencostola Loew, Neue Beitrage, vol. 5, p. 39, 1857 ; vol. 8, p. 63, 1861 ; 



Smiths. Misc. Colls., No. 171, p. 151. — Becker, Nova Acta, vol. 104, pt. 2, 



p. 74, as subgenus. 



Macquart included seven species in 1834, of which Rondani desig- 

 nated Musca diaphana Fabricius as type.^ The type of Leucostola 

 is Dolichopus vestitus Wiedemann, the only species originally in- 

 cluded. 



Since the publication of Loew's Monograph in 1864 only three 

 species have been described — aldrichi and rohusta by Johnson, and 

 ciliata by me. 



1 Trod. Dipt. Ital., vol. 1, 1856, p. 141. 



No. 2560.— Proceedings U. S. National Museum, Vol. 66, Art. 23. 



9123—25 1 1 



