AMERICAN DIPTERA. 275 



on the tergum of segment 2; pile of remaining segments almost micro- 

 scopic, yellowish on segment 3, black on the following and longer on 

 the genitalia. Venter on the proximal half with pale yellow pile. 

 Femora wholly black; the tibiae, except their tips, and the tarsi, except 

 last segment, yellowish-red; the anterior tarsi paler; pile of coxae 

 whiter; that of the femora pale yellow with a little black intermixed; 

 bristles of tibise and tarsi quite numerous, black. The anterior tibiae 

 on the outer side with fine white silky pile, which toward the base is 

 shorter and more sparse, but becoming longer and more noticeable 

 toward the tip; anterior tarsi with similar white pile on the metatarsi, 

 confined to the outer side, on the other segments on both sides, though 

 most prominent on the outer side where it is longer, and, when viewed 

 from certain positions, appears arranged in tufts corresponding to the 

 segments. There is a slight amount of white pile on the intermediate 

 tarsi, but there is no ornamental brush of black hair. Claws broadly 

 yellowish at base. Wings almost clear hyaline, venation normal, veins 

 not clouded or spotted with black. 



Type. — U. S. N. M., Cat. No. . A single male deposited 

 for safe keeping by Prof. C. P. Gillett of Colorado. 



Habitat. — Palmer Lake, Col. (July 10). 



This species somewhat resembles rufotarsus in the ornament- 

 ation of the front tibiae and tarsi, but in this species the white 

 pile is confined chiefly to the outer side, while in rufotarsus it 

 is on the upper side. These two species are easily separated 

 from those species like callipedilus and prcepes by the absence 

 of the brush on the intermediate tarsi, and by the nature and 

 arrangement of the white pile on the anterior tibiae and tarsi. 



Cyrtopogon rufotarsus n. sp. 



% 9 • — Length 9.5-11.5 mm. — Black, tarsi in both sexes reddish, the 

 front pair of the male slender, clear honey-yellow, and, together with 

 the front tibiae, clothed above with not dense short white pile. Pile 

 of body and legs for most part black, on the abdomen wholly so; seg- 

 ments 2-5 of the female abdomen and segments 2-6 of the male, with 

 interrupted white pruinose bands. Body wholly black, a typical 

 Cyrtopogon; face and front densely white pruinose, occiput somewhat 

 so; anterior portion of thoracic dorsum grayish- white pruinose, espe- 

 cially on the humeri and on either side of the median stripe, which is 

 narrowly bisected and more grayish. Pile of entire body abundant, 

 black, except a small patch on the upper portion of the facial gibbosity, 

 a small amount in the beard, that on the anterior pairs of coxag, and a 

 trifle at the base of the anterior femora below, which is white. An- 

 tenna wholly black, third segment slender at base, swollen toward tip; 



TRANS. AM. ENT. SOC., XXXV. JULY, 1909 



