156 BULLETIN 116, UNITED STATES NATIONAL MUSEUM. 



Thorax shining green with bronze reflections, which form broad 

 poorly defined vittae on the dorsum, which has yellowish white pollen 

 along the front; pleurae dulled with white pollen. Abdomen shining 

 green with coppery reflections, especially on the apical segments ; the 

 white pollen of the sides abundant and extending thinly over the 

 dorsum. Hypopygium black; its lamellae moderately large, some- 

 what quadrangular in outline, being cut off rather squarely at apex, 

 and widening out rather abruptly from the stem on upper edge at 

 base, yellowish white with a narrow black border on apical and upper 

 margins, jagged and bristly along the apical end, fringed above with 

 rather long dark hairs, below with delicate pale hairs. 



Fore coxae yellow with a brown spot at base on outer side ; anterior 

 surface with silvery white pollen, clothed with delicate pale hairs on 

 outer half and little black hairs on inner half. Middle and hind 

 coxae black with yellow tips. Femora and tibiae yellow. Middle 

 and hind femora each with one preapical bristle, the latter ciliate with 

 yellowish hairs on apical two thirds of lower inner edge, the longest of 

 these hairs fully as long as the width of the femora and near its apex. 

 Posterior tibiae deep black for one-fourth their length, a little 

 thickened; the glabrous stripe on upper surface narrow, a wider 

 glabrous stripe on the inner surface does not reach the base and is 

 separated from the one on upper edge by the inner row of large 

 bristles between which are little hairs. Fore and middle tarsi black 

 from the tip of the first joint, the former one and a fourth, the latter 

 one and a third times as long as their tibiae, rather stout; first joint 

 of fore tarsi about as long as the remaining four taken together, 

 second, third, and fourth a little narrowed at ba^e so as to give the 

 tarsi a serrated appearance; middle basitarsi brownish almost to 

 their base, without a bristle above, their tibiae with one bristle below. 

 Hind tarsi wholly black, nearly one and a half times as long as their 

 tibiae. Calypters and halteres yellow, the cilia of the latter reddish 

 yellow, but in certain lights appearing black. 



Wings (fig. 107) grayish; costa stout, a little enlarged at tip of first 

 vein, gradually tapering to its tip; last section of fourth vein bent 

 a little beyond its basal third, its tip widely separated from the tip 

 of third, which bends backward; hind margin of wing a little 

 indented at tip of fifth vein, rather evenly rounded, the anal angle 

 not being very prominent. 



Described from 1 male taken on the summit of Mount Katahdin, 

 Maine, at 5,215 feet elevation, on August 19, 1902, and 1 male taken 

 at Wyandarch, Long Island, New York, July 1, 1910, by W. T. 

 Davis. 



Type.—Male, Cat. No. 23028, U.S.N.M., from Maine. 



