THE DIPTEROUS GENUS DOLICHOPUS IN NORTH AMERICA. 241 



gray pollen. Abdomen green with bronze reflections; the white 

 pollen on its sides rather thin. Hypopygiuni (fig. 176) black, very 

 small, tipped with what appears to be the rudiments of lamellae, 

 which are whitish in color. 



Coxae yellow, outer surface of middle and hind ones blackened; 

 fore coxae covered on their anterior surface with silvery pollen, 

 with a few black hairs along the inner edge and a few longer ones at 

 base, the usual bristles at tip. Femora and tibiae yellow. Middle 

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

 bare below. Posterior tibiae a little thickened; the usual glabrous 

 stripe on upper surface distinct, but conspicuous only for half the 

 length of the tibiae, their tips slightly brownish. Fore tarsi rather 

 stout, about as long as their tibiae, black from the tip of the first 

 joint, still the second joint yellowish; first joint as long as the three 

 following taken together. Middle tioiae with two bristles below, 

 their basitarsi narrowly black at tip, without a bristle above.. Hind 

 tarsi black with the first joint yellowish on basal two- thirds and 

 with two large bristles above. Calypteres and halteres yellow, the 

 former with black cilia. 



Wmgs (fig. 176a) grayish; costa with an elongated enlargement 

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

 its middle; hind margin of wing a little indented at tip of fifth vein; 

 anal angle rounded, not prominent. 



Described from 1 male taken at Calumet, Illinois, in July, by E. P. 

 Van Duzee. 



Type.— Male, Cat. No. 23052, U.S.N.M. 



No. 177. DOLICHOPUS VITTATUS Loew. 



Dolichopus vittatus Loew, Neue Beitr., vol. 8, 1861, p. 20; Mon. N. Amer. Dipt., 

 pt. 2, 1864, p. 55.— Melander and Brues, Biol. Bull., vol. 1, 1900, p. 148. 



Male. — -Length 5-6 mm.; of wing 5-5.5 mm. Face rather wide, 

 silvery white, more or less tinged with yellow on upper portion. 

 Front shining green, often largely blue or violet. Antennae. yellow; 

 third joint more or less brown at tip, a little longer than wide, rather 

 pointed at tip. Lateral and inferior orbital cilia yellowish white, 

 about five of the upper cilia on each side black. 



Thorax green with sharply defined median, and wider, less dis- 

 tinct lateral vittae on the dorsum; often with blue or violet reflec- 

 tions, sometimes almost wholly violet on the dorsum ; the vittae are 

 usually coppery in color but sometimes they are more bronze or 

 golden, in specimens with the dorsum violet they may be shining 

 green with scarcely a trace of bronze; anterior portion of the dorsum 

 a little dulled with gray pollen; pleurae dulled with whitish pollen. 

 Abdomen green with coppery reflections; the white pollen on its sides 



