NORTH AMKRICAN DIPTERA. 



181 



mentnm of abdomen yellowish, that at apex of each segment usually reddish, 

 on apex of segments two to six black, becoming less extended on each succeeding 

 •segment; pile on sides of abdomen abundant, yellowish mixed with black, ex- 

 cept on first segment and anterior half of the second ; pile of dorsum of abdo- 

 men sparse, mixed yellowish and black ; venter reddish, sometimes partly black, 

 yellowish tomentose and pilose. Legs reddish, yellowish tomentose, underside of 

 hind legs sometimes black and black tomentose : front til)iie destitute of bristles; 

 tarsi reddish-black, claws of front tarsi minute. Wings yellowish-brown, the 

 following parts hyaline: u small spot in apex of marginal cell : in apex of first 

 submarginal cell nearly as long as second submarginal cell ; all of second submar- 

 ginal, second, third and fourth posterior cells, except border to veins, enclosing 

 these cells; and a large spot in apex of discal cell; sometimes a subhyaline 

 streak in middle of axillary cell; vein between discal and third posterior cells 

 much bowed outward and emitting a stump of a vein which projects into third 

 posterior cell. Length 11-1.5 mm. 



California !, Wyoniino-. Thivty-nine specimens in Sept.-Nov. 



Var. I'liligiiiOi^a Loew 'Syn. 1 A.fnliginosa Loew).— Diflfers from the typical 

 alpha in that the outline of the brown color of the wings is not well defined, the 

 parts of the wing that in alpha are pure hyaline are here blackish-gray, and the 

 veins between the submarginal and jiosterior cells are not distinctly bordered 

 with brown. Length 10-13 mm. 



California!, Texas ! Six specimens in Sept.-Nov. 

 This is bnt an immature form of alpha. 



49. Anthrax Willii^toiiii n. sp. (Syn. "Anthrax, sp. nov., near fulhihwsa 

 Loew" Williston, Can. Ent. vol. xi. p. 216.)— Difiers from alpha in that the middle 

 part of veins between first and second submarginal cells and between discal and 

 third posterior cell, and sometimes that between the third and fourth posterior 

 cells are not bordered with brown, and the axillary cell, except its base and apex 

 is wholly hyaline. Length 11-14 nun. 



California!, New JNIexico !, Colorado. Four specimens. 



50. Aiillirax halc.yoii Say.— Difiers from alpha in having the third poste- 

 rior cell divided by a crossvein into two cells of nearly an equal length (in two 

 of my specimens this ci'ossvein is reduced to a stump of a vein in one of the 

 wings) and the brown of the wings has a blackish tinge. Length 13 mm. 



Kansas !, Nebraska !, Colorado, British America. Six specimens. 



.")1. .iiithi'a.v coyx Loew (Syn. ? A. de.mo<ior(ion Walk.).— Front brownish, 

 the crown black tomentose and pilo.se ; face reddish, much produced below, black 

 tomentose and pilose; proboscis projects length of labellfe or less beyond ei)is- 

 toma; first joint of antenntc reddish, about three times as long as the second, 

 second and third joints black, the third elongate-conical at its base; occiput 

 black, reddish tomentose. Thorax black, reddish tomentose, front end reddish 

 pilose, sides reddish and black pilose, bristles of hind angles reddish and black; 

 pleura reddish and black i)ilose; scutellum reddish, the base black, reddish to- 

 mentose. bristles reddish and black. Abdomen black, the sides sometimes partly 

 reddish, mixed black and reddish tomentose; pile of sides black, that on sides 

 of first and second segments largely reddish, on the others mixed with a few 

 reddish ones; venter reddish, mixed reddish and black pilose. Legs reddish, 

 .sometimes partly black, reddish tomentose, front tibisB destitute of bristles; tarsi 



