120 BULLETIN 116, UNITED STATES NATIONAL MUSEUM. 



Type and .allotype. — In the collection of the Boston Society of 

 Natural History; the former was taken at Moosehead, Maine, and the 

 latter at Fogo Island, Newfoundland. 



The female from Machias, Maine, has on the fore coxae many little 

 white hairs and the fore tarsi are black from the tip of the first joint; 

 it is possible that it represents another species, but I think not. 



No. 7G. DOLICHOPUS PRAEUSTUS Loew. 



DoKchopus praeustus Loew, Mon. N. Amer. Diptera, pt. 2, 1864, p. 68. 



Male. — Length, 5 mm.; of wing, 5.5 mm. Face rather wide, yel- 

 lowish gray; front green, a little dulled with yellowish gray pollen. 

 Antennae wholly black; third joint somewhat conical in outline, about 

 as long as wide, obtusely pointed at tip. Lateral and inferior orbital 

 cilia yellowish, about five of thie upper cilia on each side black. 



Thorax green with bronze reflections, which form a median vitta 

 on the dorsum; dorsum dulled with yellowish-gray pollen, which is 

 more abundant along the front; pleurae a little dulled with white 

 pollen. Abdomen green with bronze reflections, in one specimen also 

 with blue reflections; the white pollen on its sides forming large 

 spots. Hypopygium black; its lamellae of moderate size, somewhat 

 triangular in outline, not much rounded at apex; whitish with a 

 rather narrow black border on apical margin, jagged and bristly at 

 lower corner, otherwise the apical edge is fringed with delicate 

 blackish hair; lower edge with a few delicate yellow hairs. 



Fore coxae yellowish brown, more yellow at apex and along inner 

 side (they have the appearance of not being fully colored), covered 

 on their anterior surface with little yellowish brown hairs, which 

 appear more black in certain lights. Middle and hind coxae black 

 with their extreme tips yellow. Femora and tibiae yellow. Middle 

 and hind femora each with one preapical bristle, the latter with a large 

 black spot above at tip, not ciliated but with a row of delicate little 

 yellow hairs on lower inner edge. 



Posterior tibiae only a little thickened, blackened at tip for about 

 one-fourth their length, sometimes the black extends further toward 

 the base on inner side; the glabrous stripe on upper surface broken 

 up by the irregular bristles. Middle tibiae with one bristle below. 

 Fore tarsi nearly one and a fourth times as long as their tibiae, infus- 

 cated from the tip of the first joint; first joint about as long as the 

 three following joints taken together, fifth joint slightly longer than 

 the fourth. Middle tarsi one and a fourth times as long as their tibiae, 

 black from the tip of the first joint, their basitarsi without a bristle 

 above. Hind tarsi wholly black. Calypters and halteres yellow, 

 the former with black cilia. 



Wings rather long and of somewhat equal width; grayish, tinged 

 slightly with yellow in front of third vein; costa scarcely thicker at 



