SYNOPSIS OF THE NORTH AMERICAN FLIES OF THE 

 GENUS TACHYTRECHUS. 



Bt Charles T, Greene, 

 Of the Bureau of Entomology, United States Department of Agriculture. 



INTRODUCTION. 



This synopsis is based entirely on the type material and all the 

 types have been examined by the author. The location of the type 

 is designated under each species. 



I wish to acknowledge my thanks to Dr. J. M. Aldrich for his 

 helpful criticism and suggestions and record his generous gift of 

 material from his collection to the national collection. To Mr. 

 Nathan Banks for making some additional comparisons at the Mu- 

 seum of Comparative Zoology, Cambridge, Massachusetts. To Mr. 

 M. C. Van Duzee for the gift and loan of material, and to Mr. H. S. 

 Harbeck for the gift of some specimens. 



The types of all the new species are deposited in the United States 

 National Museum. 



HISTORICAL OUTLINE OF THE GENUS. 



The genus ATn/niohates was established by Stannius in 1831 ^ with 

 the three species plumipes, notatus, and insignis, all new. Haliday 

 in 1851 changed the name to Tachytrechus ^ on account of the pre- 

 occupation of Atnmohates. Coquillett in 1910' designated Am/mo- 

 hates notatus Stannius as the type. 



In 1878 Mik* divided the genus into two genera by the following 



characters : 



Male antennae normal, like those of the female ; fourth longitudinal vein ending 

 just before the extreme apex, at a considerable distance from the tip of the 

 third Tachytrechus. 



> Isis von Oken, 1831, Heft 1, pp. 33, 268. 

 » Idem, p. 261. Tachytrechus Stannius is a nomen nudtim. 



' Type-species of the Nortn American Diptera, Proc. U. S. Nat. Mus., 1910, vol. 37, 

 p. 611. 



* Dipterologisclie Untersuchungen, 1878, p. 3. 



No. 2412— Proceedings U. S. National Museum, Vol. 60, Art. 17. 



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