178 BULLETIN 116, UNITED STATES NATIONAL MUSEUM. 



becomes more yellowish on the disk; pleurae dulled with white 

 pollen. Abdomen green with the hind margins of the segments 

 narrowly black and with bronze reflections; the white pollen on its 

 sides forms large spots on each segment and extends upon the dorsum. 

 Hypopygium black with green reflections; its lamellae moderately 

 large, somewhat round in outline, but with the lower edge straight 

 and the lower outer corner rather angulated, jagged and bristly, 

 elsewhere the upper and outer margins are fringed with short black 

 hairs and are narrowly black, the disk being white. 



Fore coxae yellow, sometimes with a brown spot at base on outer 

 side, anterior surface with conspicuous black hairs on inner half. 

 Middle and hind coxae black on outer side, yellow on inner surface 

 and at tip, the posterior ones sometimes mostly yellow. Femora and 

 tibiae yellow. Middle and hind femora each with one bristle before 

 the tip, the latter with yellow cilia on apical third of lower inner edge, 

 the hairs being about one third as long as the width of the femora. 

 Posterior tibiae thickened; their tips narrowly black; the glabrous 

 stripe on upper surface distinct and extending from near the base to 

 apical fourth where it is broken by a row of hail's ; inside of the inner 

 row of large bristles is a glabrous stripe extending their entire length 

 but widest near the base. Fore tarsi (fig. 124a) about one and a half 

 times as long as their tibiae; fii'st two joints slender, yellow, second 

 fully half as long as first, third about two-tliirds as long as second, 

 its apical half infuscated and a little widened; fourth and fifth joints 

 black, compressed, fourth fully half as long as third, about as wide 

 as long, fifth nearly as long as second, straight below, widened 

 apically, the widest point at the claws, the upper corner extending 

 beyond the claws, rather acute at tip; pulvilli white. Middle tarsi 

 one and a fourth times as long as their tibiae, darkened from the tip 

 of the first joint, the joints paler at base, tip black, basitarei with a 

 large bristle above at apical third. Hind tarsi wholly black, one 

 and a half times as long as their tibiae, Calypters and halteres 

 yellow, the former with black cilia. 



Wings (fig. 124) grayish; costa with a slight knot-like enlargement 

 at tip of first vein ; last section of fourth vein bent before its middle ; 

 hind margin of wing a little indented at tip of fifth vein; anal 

 angle prominent, the wing being of somewhat equal width; hind 

 margin a little sinuated. 



Female. — Differs from the male in having the face wide with grayish 

 pollen; fore tarsi plain, a little longer than their tibiae, infuscated 

 from the tip of the first joint; middle tibiae with three bristles below, 

 one pair at apical third and one bristle at basal third; hind femora 

 without cilia below; hind tibiae less thickened and without the 

 glabrous stripe on inner surface; costa not enlarged at tip of first 

 vein; wing a very little wider. 



