168 BULLETIN 116, UNITED STATES NATIONAL MUSEUM. 



in outline, but narrowed at base, a])Out twice as long as wide, yellow- 

 ish white with a broad black border on apical, and narrow border 

 on upper margin, jagged and bristly at apex, fringed with black 

 hairs above. 



Fore coxae yellow, blackened at tip for nearly one half their length, 

 their anterior surface covered with coarse black hairs. Femora and 

 tibiae yellow. Middle and hind femora each with one preapical 

 bristle, the latter ciliated on lower inner edge for one-third their 

 length with yellow hairs, the longest of which is a little shorter than 

 the width of the femora. Posterior tibiae thickened, especially at 

 tip, black at tip for more than one fourth their length; the glabrous 

 stripe on upper edge distinct, their inner surface nearly glabrous on 

 its basal two-thirds ; on the lower outer edge there is a row of about 

 six, regularly placed bristles of nearly equal length, which are about 

 as long as the thickness of the tibia. Fore tarsi (fig. 116a) one and 

 a third times as long as their tibiae; second joint about three-fourths 

 as long as the first, third shorter than the second, fourth short, 

 slightly compressed, about as long as wide; first three joints yellow, 

 fourth yellow with brownish tip, fifth black, much compressed, not 

 as long as third, somewhat triangular, about as wide near the tip as 

 long. Middle tarsi black from the tip of the first joint, which has 

 several small bristles on its sides and below, and one small bristle 

 above. Middle tibiae with three large bristles on lower anterior 

 surface and two on lower posterior edge, sometimes one of these 

 seems to be missing. Hind tarsi wholly black. Calypters and 

 halteres j^ellow, the former with yellow cilia which sometimes appear 

 to be almost black in certain lights. 



Wings grayish; costa with a slight elongated enlargement at tip 

 of first vein; last section of fourth vein bent near basal third; third 

 vein bent backward at tip, but the tips of third and fourth rather 

 widely separated; hind margin of wing scarcely indented at tip of 

 fifth vein; anal angle rather prominent but rounded. 



Female. — Face a little wider than in the male; antennae as in the 

 male except that the arista is plain, still it has a small but distinct 

 thickening at its middle; fore tarsi plain, one and a third times as 

 long as their tibiae, infuscated toward their tips, but only the fifth 

 joint black, first joint as long as the three following taken together, 

 fourth scarcely as long as fifth; hind femora without cilia below, 

 their tibiae but little thickened, blackened a little at tip, not glabrous 

 on inner surface, with the row of bristles on lower outer edge larger 

 and less regularly inserted than in the male; middle basitarsi with a 

 large bristle above; cilia of the calypteres black, still somewhat yellow- 

 ish in certain lights; wings more tinged with brown; costa not 

 thickened at tip of first vein. 



