THE DIPTEROUS GENUS DOLICHOPUS IN NORTH AMERICA. 117 



scarcely indented at tip of fifth vein; rather evenly rounded; anal 

 angle moderately prominent, but rounded. 



Female. — Face wide, covered with white pollen; thorax and front 

 femora more blue than in the male; fore coxae, hind femora, and 

 hind tibiae about as in the male ; fore and middle tarsi slightly shorter 

 than in the male. Middle tibiae with one bristle below, their basitarsi 

 without a bristle above. 



Described from many males and females which were taken as 

 follows: At Algonquin, Illinois, June 4 (Nason) ; by me at Lewiston, 

 New York, May 30; Erie County, New York, May 30 to August 4; 

 Tonawanda, New York, August 4; Fort Erie, Ontario, June 20; 

 Toronto, Ontario, August 12; also 1 female. Turtle Mountains, near 

 Bottineau, North Dakota, June 21. (Aldrich.) 



This species differs from sincerus Melander by having the fore 

 coxae mostly yellow, only infuscated at base, in sincerus they are 

 almost wholly black with the tip narrowly yellow; the hypopygial 

 lamellae are larger and wider at base here, the fore part of the wing 

 brownish and the face silvery white. 



Type.— Male, Cat. No. 23015, U.S.N.M., from Erie County, New 

 York. 



No. 73. DOLICHOPUS SINCERUS Melander. 



Dolichopus sincerus Melander, Canadian Ent., vol. 32, 1900, p. 136, figs. 



Male. — ^Length 3.75-4.5 mm.; of wing 3-4 mm. Face rather wide, 

 silvery white, sometimes quite yellowish on upper three-fourths. 

 Front dark shining green, sometimes violet (Melander says "brassy- 

 green"). Antennae wholly black; third joint a little longer than wide, 

 somewhat oval in outline but rather pointed at tip. Palpi dark 

 yellow with white pollen. Lateral and uiferior orbital cilia yellowish, 

 the black cilia descending about one-fourth the eye height. 



Thorax dark shining green (Melander states "brassy-green, more 

 cupreous along the sides and with two cupreous stripes in front"); 

 pleurae dulled a little with grayish pollen. Abdomen green with 

 black incisures, which are bordered with cupreous; the white pollen 

 on its sides abundant, extending upon the dorsum. Hypopygium 

 black; its lamellae of moderate size, somewhat triangular in outline, 

 white with a broad black border on apical margin, which is jagged and 

 bristly. 



Coxae black with narrow yellow tips; anterior pair with white 

 pollen and little black hairs on the front surface; the middle coxae 

 usually have a few white hairs mixed with the black ones. Femora 

 yellow. Middle and hind femora each with one preapical bristle, the 

 latter black at tip, except below, as far as the preapical bristle; in the 

 type specimen the black hairs on inner surface descend to the lower 

 edge, not even leaving the usual glabrous stripe on lower edge, but in my 



