1923] 
The Genus Cyrtopogon 
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the anterior ones half way to the front margin; pile abundant 
and black, three fine lateral bristles; scutellum convex, shining 
blue-black, its silky pile long and white, no bristles, pleurae 
uniformly and lightly cinereous dusted, ground-color blue-black, 
pile of pectus white, trichostichal hairs white and black mixed. 
Abdomen shining blue-black, extreme posterior corners of seg- 
ments white pruinose, pile rather sparse short and pale, becoming 
darker in back, hypopygium very small, sunken, venter with 
bluish-gray pile, the hairs very dense on apical third. Legs en- 
tirely blue-black, front coxae with abundant whitish pile, hairs 
of femora pale at base, front tibiae with a row of very long bluish 
hairs on posterior edge, these hairs continuing on first three 
tarsal joints, hind tibiae brown pubescent within, claws 
black, pul villi brownish. Halteres black, calypteres alutaceous; 
wings lightly infumated, paler along portions of the first three 
veins, marked with distinct blackish spots at the bases of sub- 
marginal cells and of first and second posterior cells, the last two 
spots sometimes thickened and extending basally to the cross- 
veins, costa blackish from end of first vein to tip of wing. 
Female . — Hairs somewhat shorter, notum more heavily 
pollinose so as to appear brownish in general color, median bi- 
sected stripe almost black; scutellum brownish pollinose, with 
about eight marginal setiform hairs; front legs marked with a 
prominent comb of hairs. 
Types . — Moscow Mountain, Idaho, various dates from May 
to October (Melander); Pullman Washington; Goodnoe Hills, 
Washington (A. C. Burrill). 
Cyrtopogon semitarius, new species. 
Male . — Length 15 mm. Resembling dasyllis. Upper part 
of head black with abundant black hair, facial hair mainly white, 
along oral margin black, beard fine and white, palpal hairs 
black, antennae black, style deformed, as wide as long, blunt, 
apically with a concavity in which the minute terminal joint is 
inserted. Thorax largely shining, a very narrow indistinct 
median line of grayish-brown dust, a mark of similar dust bear- 
