THE DIPTEROUS GENUS DOLICHOPUS IN NORTH AMERICA. 189 



with coppery reflections; the white pollen on its sides rather thin. 

 Hypopygiuni black; its lamellae (fig. 132a) small, oval, whitish with 

 a narrow black border on apical margin, which is jagged and bristly, 

 fringed above with brown, below with a few pale hairs. 



Coxae yellow, middle pair a little brownish on outer side; fore 

 coxae with minute, delicate, yellowish hairs on the anterior surface. 

 Femora and tibiae yellow. Middle femora with one stout and one 

 slender preapical bristle; hind femora with one rather long curved 

 preapical bristle, ciliated below with a few long whitish hairs, the 

 longest of which are as long as the width of the femora. Posterior 

 tibiae a little brownish at tip, but little thicker than the others. 

 Fore tarsi one and a fourth times as long as their tibiae, black from 

 the tip of the first joint, which is as long as the three following joints 

 taken together, fourth joint a little longer that the fifth. Middle 

 tarsi a little longer than their tibiae, black from the tip of the first 

 joint, which has a large bristle above; middle tibiae with three bris- 

 tles below, two near apical third and one near basal third. Hind 

 tarsi wholly black. Calypters and halteres yellow, the former with 

 black cilia. 



Wings (fig. 132) tinged with brownish gray; costa with a rather 

 small knot-like enlargement at tip of first vein; last section of fourth 

 vein a little bent at basal third; hind margin of wing scarcely indented 

 at tip of fifth vein, rather evenly rounded, the anal angle not being 

 prominent; the wing widest just basally from the tip of fifth vein, 

 narrowing from that point to the root of the wing. 



Female. — Agrees with the male in the color of the front, thorax, 

 abdomen, legs, feet, and wings, also in having pale hairs on the fore 

 coxae, and in the form of the wing, except that the costa is not 

 enlarged at tip of fifth vein and the wing is perhaps a little broader. 

 It differs in having the face wide, grayish white ; the fore tarsi shorter, 

 being about as long as their tibiae; and the hind femora without 

 cilia below; the middle and hind femora each have one preapical 

 bristle. The bristles on middle tibiae and basitarsi are as in the 

 male. 



Described from 2 males and 2 females, taken in Polk County, 

 Wisconsin, in July, by C. F. Baker, and given by him to J. M. 

 Aldrich. 



r^/^e.— Male, Cat. No. 23034, U.S.N.M. 



No. 133. DOLICHOPUS VARIABILIS Loew. 



Dolwhopus variabilis Loew, Neue Beitr., vol. 8, 1861, p. 17; Mon. N. Amer. 

 Dipt., pt. 2, 1864, p. 50.— Aldrich, Kansas Univ. Quart., vol. 2, 1893, p. 11.— 

 Melander and Brues, Biol. Bull., vol. 1, 1900, p. 148. — Johnson, Insects 

 of New Jersey, 1909, p. 756. 



Male. — Length 4-5 mm.; of wing 4-4.5 mm. Face narrow, yel- 

 lowish, more white near the palpi. Front shining green. Antennae 

 187329—21 13 



