598 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. 50. 



scrobes shallow and broad, uniting above, the facial prominence very 

 slight; eyes weakly pubescent. Antenna! scape over one-half as 

 wide as long, widest across the middle; pedicel as long as the first 

 three funicle joints combined; all funicle joints wider than long, and 

 increasing in width distad, the last two slightly longer than the pre- 

 ceding, the sixth about twice as wide as long; club about one-fifth 

 wider than preceding joint, subrectangular with the apex truncate, 

 nearly as long as the last four funicle joints combined. Wings not 

 uniformly ciliated, all cilia very dense and black except for a narrow, 

 curved band at end of stigmal vein where the cilia are colorless 

 although as dense as elsewhere; oblique hairless streak extending 

 about two-thirds of the way across disk from the stigmal vein. 

 Length: 1.0 to 1.4 mm. 



Front, vertex, and rim of occiput pale yellow, face and cheeks 

 yellowish white, the latter with a brown streak on their lower cor- 

 ners extending narrowly nearly across the oral margin of face ; center 

 of occiput, concealed part of pronotum, and most of thorax above 

 blackish brown, the mesoscutum narrowly edged with yellowish on 

 the sides; collar of pronotum and the tegulae whitish, the former 

 with a small, round, blackish brown dot on each corner, the latter 

 with a light brown spot on posterior margin; abdomen above nearly 

 pure black with a yellowish white, narrow, submarginal streak on 

 each side posterior to the vibrissal plates; underparts yellowish 

 white, the venter of abdomen with the sides narrowly and a broad, 

 median, longitudinal band blackish brown. Antennal scape black 

 with upper margin white, and a pale, oval spot on outer face at and 

 near the base; base of pedicel, first three funicle joints and club 

 nearly pure black; apex of pedicel and last three funicle joints 

 white. Legs yellowish white, the femora with two interrupted bands, 

 the tibiae with three narrow annuli of blackish brown; tarsi more 

 yellowish with last joint blackish. Wings conspicuously dusky, due 

 entirely to the black ciliation, and with a narrow whitish band at end 

 of stigmal vein, of which the basal margin is concave and the apical 

 margin straight and transverse. 



Male. Front and vertex about one and a half times as long as 

 wide; ocelli in nearly an equilateral triangle, the posterior pair 

 nearly touching the eye margin; eyes thickly pubescent. Antennae 

 as in the female except that the scape is much narrower, about one- 

 fourth as wide as long, its lower margin forming a slight curve, the 

 funicle and club a little slenderer. Wings have the ciliary infusca- 

 tion much less conspicuous than in the female, and developed to 

 about the same degree as found in the females of A. rileyi. Length: 

 1.3 mm. 



Coloration almost the same as in the female, but the spot on the 

 cheeks is much smaller or nearly obsolete; the yellowish white on 



