544 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 113 
14. Posterior edge of surstylus of male distinctly receding below; spines at tip 
of abdomen of female less than the width of the posterior end of the ter- 
minal abdominal segment... . . . . . . coloradense Garrett 
Posterior edge of surstylus of male not cheemre dy receding below; spines at 
tip of abdomen of female may be about as long as the width of the posterior 
end of the terminal abdominal segment. . jersei Garrett (=hinei Garrett?) 
Anorostoma cinereum Curran 
Anorostoma cinereum Curran, 1932, p. 10; p. 2. 
Anorostoma cinereum Curran, A. maculatum Darlington and A. 
opacum Coquillett are very similar to one another in chaetotaxy, 
coloration, and appearance of the male terminalia. A. cinereum 
Curran may be distinguished from the others in that it lacks a black 
spot between the antenna and the eye, and the wings have less area 
darkened with gray. Cell R, is almost entirely whitish. 
Matrn.—Cheeks, face, fronto-orbital plates, vertex, and back of 
head with a silvery pollinosity, sometimes becoming faint yellowish; 
front yellow to yellowish brown; ocellar triangle darker gray; area 
between antenna and eye appearing yellowish orange to silvery gray, 
depending upon the light, but never as a blackish spot; antennae 
dark brown to black, including the aristae, which are relatively short 
and are minutely pubescent; aristae with a white ring in proximal half; 
front with sparse setae, mostly towards anterior half; oral vibrissae 
weak, about as long as the third antennal segment; a single row of 
sparse weak buccal setae; cheek-eye ratio from 1.1 to 1.2. 
Thorax mostly a pollinose silvery gray; upper half of mesopleuron 
and the humeral callosity sometimes appearing yellowish; a yellowish 
shading may extend through the presuturals to anterior supra-alars, 
with a similar shading through the dorsocentrals; the latter shading 
may become dark brown posteriorly and the 2 darkened areas through 
the dorsocentrals may merge in the region of the prescutellars; 
scutellar bristles may each arise from a brown spot; mesopleuron 
with a single strong bristle along the posterior margin, with some- 
times 1 or 2 small hairs near it; sternopleuron with 1 strong bristle, 
with scattered setae anterior to it, forming 1 to 3 irregular rows down 
the middle to the longer hairs between the coxae. 
Legs silvery gray to yellowish. 
Wings mostly whitish, with darkened gray areas near the end of 
the subcostal vein, along the anterior crossvein, along the anterior 
half of the posterior crossvein, in the discal cell, and in the first, 
second, and third posterior cells; in the marginal cell (cell R,), there 
is a very small, hardly noticeable gray area. 
Abdomen a pollinose silvery gray; scattered small setae above, but 
a bare longitudinal area forms a vitta down the middle; hypopygium 
large, its setae sparse. 
