THE DIPTEROUS GENUS DOLICHOPUS IN NORTH AMERICA. 115 



Lateral and inferior orbital cilia whitish, about eight of the upper 

 cilia on each side black. 



Thorax green with more or less coppery reflections; dorsum with 

 a very little brown pollen which can be seen only when it is viewed 

 obliquely; pleurae dulled with white pollen. Abdomen shining green 

 with coppery reflections, which are more conspicuous on the hind 

 margins of the segments; the white pollen on its sides rather abun- 

 dant. Hypopygium black ; its lamellae (fig. 71a) rather large, some- 

 what triangular but rounded on upper corner, nearly as wide as long, 

 white, with a narrow black border on the apical margin, which is 

 jagged and bristly. 



Coxae black with yellow tips; anterior pair with the yellow ex- 

 tending to the middle on the front surface, which is covered with 

 silvery white pollen and little black hairs; the hairs on the outer 

 edge of the front side are minute and white. Femora yellow; an- 

 terior pair brown on the upper surface. Middle and hind femora 

 each with one preapical bristle, the latter black at tip as far as 

 the preapical bristle, without cilia below; the little hairs on both 

 inner and outer surface wholly black. Tibiae yellow; posterior 

 pair a little thickened, black for about one-fourth their length, 

 the glabrous stripe between the rows of bristles on upper sur- 

 face broad. Fore and middle tarsi a little longer than their tibiae, 

 black from the tip of the first joint, the former with the first joint 

 nearly as long as the remaining four joints taken together, third 

 and fifth joints of equal length, fourth slightly shorter. Hind tarsi 

 wholly black, about one and a fourth times as long as their tibiae. 

 Calypters and halteres yellow, the former with black cilia. 



Wings (fig. 71) grayish, tinged with brown in front from the tip 

 of the first vein back as far as the third vein; costa scarcely thickened 

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

 middle; hind margin of wing slightly indented at tip of fifth vein, 

 rather evenly rounded, the anal angle not being much developed. 



Female. — Differs from the male m having the face wide, white 

 but not silvery; the fore femora are brown, above as in the male, 

 the middle tibiae have one bristle below, their basitarsi are without 

 a bristle above. 



Described from 8 males and 1 female, taken an Mount Constitution, 

 Orcas Island, Washington, July 7, 1905, by J. M. Aldrich. 



Type.— Male, Cat. No..23014, U.S.N.M. 



This species differs from wplieles Melander and Brues in having 

 the face narrow and silvery (it is wide and yellowish gray in apTieles) 

 and in having the hypopygial lamellae larger and the fore femora 

 brown above. From discolor, new species, it differs in having the 

 fore coxae largely black and the fore femora brown above, in discolor 

 the fore coxae are mostly yellow and the fore femora not at all 



