THE DIPTEROUS GENUS DOLICHOPUS IN NORTH AMERICA. 91 



than their tibiae, wholly pale yellow; first joint a little longer than 

 the remaining four taken together and with a row of about ten black 

 bristles on lower inner edge, which are nearly as long as the second 

 joint, last four joints a little compressed and covered with silvery 

 pollen, third and fourth each a little shorter than the preceding joint, 

 fifth a little longer than the fourth. Middle tarsi as long as their 

 tibiae, infuscated from the tip of the first joint, but scarcely black. 

 Hind tarsi wholly deep black. Calypters and halteres yellow, the 

 former with black cilia. 



Wings (fig. 49«) grayish; costa with a knot-like enlargement at tip 

 of first vein; last section of fourth vein a little bent near its middle; 

 hind margin of wing a little indented at tip of fifth vein, rather 

 evenly and broadly rounded; anal angle a little prominent. 



Female. — Face as broad as the front, white; hind femora without 

 cilia; fore tarsi as long as their tibiae, darker yellow than in the male, 

 sometimes the joints brown or blackish at tip, first joint with a row 

 of hairs below which are as long as the width of the joint, last four 

 joints without the silvery pollen found in the male; costa not enlarged 

 at tip of first vein; otherwise about as in the male; middle tibiae with 

 one bristle below, their basitarsi without a bristle above. 



Described from 5 males and 5 females, taken at Lafayette, Indiana, 

 June 3-S, 1915, by J. M. Aldrich. 



JVpe.— Male, Cat. No. 23001, U.S.N.M. 



No. 50. DOLICHOPUS REMIPES Wahlberg. 



Dolichopus remipes Wahlberg, Vetensk. Akad. Handl., 1838, p. 20. — Zetter- 

 STEDT, Dipt. Scand., vol. 2, p. 518. — Aldrich, Cat. N. Amer. Diptera, 1905, 

 p. 304. 



hale. — Length 5.2 mm. ; of wing 5 mm. Face rather wide, its sides 

 nearly parallel, long, extending down nearly to the lower corner of the 

 eyes, silvery white. Front dark shining green. Antennae wholly 

 black; third joint about as long as wide, somewhat orbicular in out- 

 line; arista nearly twice the length of the antennae. Lateral and in- 

 ferior orbital cilia white, long and conspicuous below, about twelve of 

 the upper cilia on each side black. 



Thorax dark blue green; pleurae dulled with gruy pollen; scutellum 

 fringed with short yellow hairs; it sometimes has violet reflections, 

 which extend upon the posterior part of the thorax. Abdomen green, 

 with black incisures, second segment sometimes bluish, the white 

 pollen on its sides abundant, the sides also have rather long white hair, 

 Hypopygium black or testaceous, sometimes more yellowish toward 

 the apex; its lamellae large, somewhat triangular, white -with black 

 border, very narrow except at inner angle where it is broad: a little 

 jagged, bristly on lower corner, otherwise fringed with small hairs 

 placed rather far apart. 



