211 
1923] Studies in Asilidce (Diptera) 
2. Antennae black; anterior cross vein at middle of discal cell; 
plurae with golden spots. (Cal.) pictus Cole. 
Base of antennae yellow; anterior crossvein beyond middle 
of discal cell 3. 
3. Abdomen with large triangular pollinose marks; bristles 
yellow; femora reddish. (Cal.) gilvipes Coq. 
Abdomen polished, with gray pruinose spots at base of 
segments 2-6; bristles black; femora black except knees. 
(N. Mex.) punctipennis Coq. 
4. Mainly black, abdomen with small pruinose spots; wings 
of male white on basal half, lightly infumated apically, 
of female uniformly lightly infumated; mystax stiff and 
black.» (Wash., Id., Or., Cal.) setiger Cole. 
Body mainly cinereous, base of abdominal segments black; 
wings hyaline; mystax white. (Wash.) . .alhidus, n. sp. 
Metapogon albulus, new species 
Male. — Length 7 mm. Black, entirely and heavily coated 
with silvery gray pruinosity, leaving only the bases of abdominal 
segments showing black. Bristles of face and front white, 
ocellar bristles black; third antennal joint widest at three-fifths 
its length, the style almost microscopic, setae below basal joints 
of antennae black; beard sparse and white, upper part of oc- 
ciput bare except for the row of white setae. Bristles of anterior 
part of thorax white, of posterior part black, four or five stout 
bristles in dorsocentral row, posthumeral bristle present, white, 
two siipraalar bristles, scutellum with two marginal bristles, 
otherwise bare, two to five hypopleural setae, pleurae devoid of 
pile except on prothorax. Pile and setae at sides of first ab- 
dominal segment white, remaining segments with very sparse 
short white hairs, base of segments two to five very narrowly 
devoid of pruinosity, hypopygium small black and inserted in 
the end of the cylindrical abdomen, its hairs pale and rather 
sparse; venter entirely glaucous. Legs black, the coxae alone 
pruinose, knees very narrowly yellowish, femora with a few small 
white flexor bristles, bristles of tibiae white except those at apex, 
tarsal bristles black, claws black, pulvilli brownish, hairs of legs 
