266 DIPTERA OF NORTH AMERICA. [PART II. 



. Abdomen with extremely narrow Lands ; halteres yellow ; feet black, 

 fore and middle tibiae yellow. Long. corp. 0.19 — 0.23. Long. al. 0.18 

 —0.20. 



Syn. PsUopus chrysoprasi Walker, List, etc. Ill, 646. 



Psilopus chrysoprasi us Loew, Neue Beitr. VIII, 90, 8. 



Hale. Very shining, green, the head, the hind part of the 

 thorax, the scutellum, and the anterior segments of the abdomen 

 more steel-blue, the last segments of the abdomen sometimes 

 golden-green. Palpi black ; proboscis brown. Face without 

 hairs, thinly dusted with white ; its upper part rather convex. 

 The bristles on the second joint of the antennas rather long ; the 

 arista dorsal and of ordinary length. Front with a long whitish 

 pubescence and the usual black bristles upon the thorax and the 

 scutellum of a rather considerable length. The black bands of 

 the abdomen are narrow upon the anterior segments and of con- 

 siderable breadth upon the posterior ones. The black pubescence 

 of the abdomen is rather short ; upon its first segments, as also 

 upon the anterior part of the lateral margin and the venter there 

 is a delicate white pubescence, while the hind part of the venter 

 has a black pubescence of considerable length. The black bris- 

 tles before the incisures of the abdomen are numerous, but rather 

 short. . The small hypopygium black, its lamellae dark-brown. 

 Coxae black, the foremost with a considerable white pubescence 

 and a few. black bristles. Femora black with a greenish reflection, 

 upon the under side with a long, upright, whitish pubescence. 

 Fore tibiae brownish-yellow, fringed with only a moderate number 

 of short black bristles. Middle tibiae brownish-black, sometimes 

 nearly black, beset upon the front side with a regular row of black 

 bristles, otherwise only with a small number of them ; upon the 

 upper side with rather bristle-like black hairs. Hind tibia? black 

 with coarse black hairs, upon the outside fringed with a regular 

 longitudinal row of black, only moderately long, bristles. Fore 

 tarsi rather slender, about once and a third the length of the 

 tibia 1 ; the first joint brownish-yellow, much longer than the 

 following taken together, upon the hind side with three or four 

 stout black bristles; the following joints blackish-brown, from 

 the second to the fourth of rapidly decreasing length, the fifth as 

 long as the fourth. Middle tarsi about once and a half the length 

 of the tibiae ; the first joint black-brown, nearly twice the length 



