258 BULLETIN 116, UNITED STATES NATIONAL MUSEUM. 



and inferior orbital cilia yellow, about eight of the upper cilia on each 

 side black. 



Thorax bright sliining green; still it has considerable white pollen 

 on the dorsum, especially along the front, and it leaves three shining 

 vittae, which are more or less coppery; sometimes the posterior por- 

 tion of the dorsum and the scutellum is more blue or violet. Abdomen 

 green with coppery reflections; the white pollen on its sides abundant. 

 Hypopygium black; its lamellae rather large, whitish with wide 

 black border on their apical margin, which is jagged and bristly on 

 lower half, fringed above this with yellowish hairs; they are some- 

 what triangular in outline, but broadly rounded on upper corner. 



Fore coxae yellow, anterior surface covered with little black hairs: 

 middle and hind coxae black with yellow tips; femora and tibiae 

 yellow; middle and hind femora each with one preapical bristle, the 

 latter, ciliated on the central half of lower inner edge with dense 

 yellow hairs, which are not as long as the width of the femora. Middle 

 tibiae with four bristles below, one at basal and two at apical third 

 and one between these, their basitarsi with a large bristle above near 

 apical third. Posterior tibiae thickened, especially in the middle; 

 inner surface glabrous for more than half their length and a little 

 excavated on tliis portion, fringed below with an irregular row of 

 bristles. Fore tarsi (fig. 189) about one and a half times as long as 

 their tibiae; first three joints normal, yellow, fourth white, fifth 

 black; first joint nearly as long as the two following taken together, 

 third one-third as long as second and a little longer than fourth, a 

 very little widened at tip; fourth and fifth joints compressed, fourth 

 widening at tip, apical edge brownish, fifth a little longer than the 

 tliird and fourth together, somewhat pear-shaped in outline, two- 

 tliirds as wide as long, with a minute fringe of white hairs on apical 

 edge; fourth and fifth joints fringed above with black hairs, fifth 

 with a silky luster on the sides, whicli varies from black to silvery ac- 

 cording to the angle from which it is viewed. Middle tarsi only a little 

 longer than their tibae, black from the tip of the first joint. Usually 

 the hind tarsi are black from the extreme tip of the first joint, but 

 sometimes the whole of fii'st and bases of following joints are yelloM. 

 Calypters, their cilia and the halteres yellow. 



Wings a little grayish; costa with an elongated enlargement at tip 

 of first vein; last section of fourth vein bent a little beyond its basal 

 third; hind margin of wing slightly indented at tip of fifth vein; 

 anal angle quite prominent, still cut off from a point a little beyond 

 the tip of sixth vein, scarcely rounded, but somewhat flattened in 

 outline. 



Female. — Face wide, yellowish white; fore tarsi plain, a little longer 

 than their tibiae, infuscated from the tip of the first joint, still the 

 joints following yellowish at base, fifth joint as long as third, fourtli 



