4-S 



2. Without any fascij^i of gray polleu on the abdomen, which is sub- 



shining and almost or wholly <lestitute of pollen ny^i-.j-A-^- 6K3. 

 With an opaijue, interrupted lasi'ia of yellowish j)ollen on the second, 

 third, and fourth segments of tlic abdomen ;Ascutellum and 

 femora yellow, thorax shining black, the portion in front of the 

 transverse suture yellowish pollinose and marked with three or 

 four black vitta-i; wings brown, the costal margin more or less 

 yellow, tlie hind margin broadly hyaline; lower^ah'pteres yel- 

 lowish; /length, 7 to 11 mm. District of Columbia; Texas, and 

 Napa County, Oal. (Systema Antliatorum, p. 220; 1S05: The- 

 reva. TrlcliopoiUi histrio \Valker, List of Dipterous Insects, 

 Part IV, p. G97; 1849. Tr/c/ioj;of?rt tri/asciato Loew, Dipt. Amer. 

 Sept. Indigena, Centuria IV, No. 90; 1803: also Brauer and 

 Dergenstamm in litt.) r^.^. . . .plmnipes Fabr. 



3. Lower calypteres wholly yellowish; abdomen bright yellow, the apex 



sometimes black; legs black, bases of femora sometimes yellow, 



u> »'-«.<*» n-t«,»-rt>i*»rhind margin of wings subhyaline 4. 



Lower calypteres bwwu, the bases white ; abdomen yellowish brown, 

 the fifth segment yellow, legs black, the bases of the middle, 

 and hind femora sometimes yellow; wing^)rowu,Aa ^^4»ite viyia-' 

 along each of the first five veins, hind margin subnyaliue; 

 length 14 to 17 mm. District of Columbia; Waco, Tex., and 

 ^^ Tehuantepcc, Mexico. ( Aussereuropiiische Zweif. Insekten, Vol. 

 II, p. 268; 18'K). Trleltopoda rarliata Loew, Dipt. Amer. Sept. 

 Indigena, Centuria IV, No. 89; 1803: also Brauer and Bergen- 

 stamm in litt.) .-^ formosa Wied. 



4. Penultimate section of fourth vein of male bordered in front with 



whitish, the first five veins usually partly bordered with white, 

 u s u,. ftU u a yellowish spot on front part of each wing of the male; length, 

 9 to 14 mm. West Roxbury, Mass. ; District of Columbia; Vir- 

 ginia; Tifton, Ga. ; Biscayne Bay, Florida; Cadet, Mo. ; Douglas 

 County, Kans., and Texas. (Aussereuropiiische Zweif. Insek- 

 ten, Vol. II, p. 270; 1830. Thereva pennipcs Fabricius, Systema 

 Antliat,,p. 219; 1805: non MnscapouiipcsFahvicms,; 1794. Tri- 

 chopoda aurantlaca Townsend, Proc. Fnt. Soc. Washington, Vol. 



II, p. 140; April 2, 1891.) /7u;ilipes Wied. 



Penultimate section of fourth vein not bordered with whitish in 

 either sex, any of the veins rarely bordered with whitish; wings 

 of male usually but not always marked in front Avith a yellow 

 spot; length, 7 to 12 mm. Urimsby, Canada; Belmont, Mass.; 

 Philadelphia, Pa.; District of Columbia; North Carolina; Flor- 

 ida; Mississippi; Lexington, Ky.; Missouri; Onaga, Kans.; 

 Colorado; Los Angeles County, Cal., and Mexico. (Entomolo- 

 gia Systematica, Vol. IV, i). 348; 1794: Musca. Thereva hirtipcs 

 Fabricius, Systenui Antliat., p. 219; 1805. Oeijptcra eiliata 

 Fabricius, loc. cit., p. 315. Phasia juyatona Say, Jour. Acad. Nat. 



