AKT. 17. FLIES OF THE GENUS TACHYTRECHUS GREENE. 19 



Female. — Very much like the male. The color is more of a bronze 

 color; hind tibiae without the flattened bristles on the hind side. 



Type locality. — District of Columbia. 



Distribution — District of Columbia ; Chisos Mountains, Brewster 

 County, Texas, June 10 to 12, 1908, Mitchell and Cusliman, collect- 

 ors; Mount Lowe, California, July 4, 1917; Austin, Texas, May 11 

 to 18, 1900; Pasadena, California, August, R. W. Doane; Pacific 

 Grove, California, May 5, 1906; Owen's Lake, California, July 27, 

 1911; Stanford University, California, April 12, 1906; Jacumba 

 Springs, California, June 28, 1917, J. M. Aldrich; Indian School, 

 Pyramid Lake, Nevada, July, 1911; Mono Lake, California, July 23, 

 1911; Highland Springs, Lake County, California, August 9, 1911, 

 J, M. Aldrich, collector; San Diego, California, April 6, 1915, M. 

 C. Van Duzee. Brewster County, Texas, Chisos Mountains, June 

 10 to 12, 1908, Mitchell and Cushman, collectors. United States Na- 

 tional Museum Collection. 



Type. — In Museum of Comparative Zoology, Cambridge, Massa- 

 chusetts. Eight specimens deposited in United States National 

 Museum Collection by J. M. Aldrich. 



16. TACHYTRECHUS PROTERVUS Mel8nd«r. 



Tac7iytrec?u(s protervus Melandeb, Can. Ent., 1900, vol. 32, p. 143, figs. 6, 7. 

 Tachyfrechus juncttis Coquillett, Proc. Ent. Soc. Wash., 1910, vol. 12, 

 p. 125. 



Male. — Face heavily coated with a silvery dust, below the antennae 

 about half as wide as at the lower end. Front dull, violet brown. 

 Antennae mostly dull yellow; first joint enlarged at apex; second 

 joint with black bristles just below apex; third joint about as long 

 as the first two, with a brown infuscation along upper half. Arista 

 dark brown, thickened basally and not quite as long as the face. 

 Orbital cilia black above, yellowish below. Thorax piceous green; 

 above the base of the wing is a horizontal velvety black spot, above 

 this the dorsum is cupreous; a large silvery area in front of this 

 black spot; on the posterior corners touching the basal corners of 

 the scutellum is a rounded silvery spot. Scutellum like dorsum of 

 thorax. Abdomen dark green, silvery-dusted along the sides, in- 

 cisures well marked. In some lights there is a reddish or violaceous' 

 tinge. Hypopygium piceous, lamellae subrectangular, dark, hairy, 

 evenly fringed with short black hairs, which are longer dorsally 

 toward base. Pleura black, silvery dusted ; coxae concolorous except 

 extreme tip, fore coxae bronze-dusted in front. Legs black except 

 the following : Tips of femora below, basal two thirds of middle and 

 hind tibiae and front metatarsi, rather dark yellowish. Forelegs 

 ornamented as follows: Tibiae thickened, dusted with yellow on 

 anterior surface, and with longitudinal rows of short black bristles; 

 tarsi compressed, first joint a little shorter than the rest together. 



