AMERICAN DIPTERA. 283 



Loew was right in regarding this species not the female of 

 montanus, for I have seen males and females of the latter 

 from British Columbia, Canada. The females described by 

 Osten Sacken as montanus agree with the B. C. females. The 

 white pile of the thoracic dorsum is most prominent upon the 

 posterior callosities and immediately before the scutellum, 

 and is best seen from in front and a little to one side. 



Cyrtopogon dubiiis. 



Cyrtopogon diibius Williston, Trans. Am. Ent. Soc, XI, 13, 1884. 



" 9. — Length 11 mm. — Scutellum flattened, gray pruinose above- 

 abdomen polished black, first segment on the sides, and the four fol; 

 lowing, with interrupted posterior cross-bands of gray bloom; femora 

 black, tibiae and tarsi dark red; head, except the beard, wholly black 

 pilose, antennae black; wings with narrow brown clouds on the cross- 

 veins. 



"Face thickly whitish pruinose and densely black pilose; beard be- 

 low white ; on the sides and above black. Dorsum of thorax deep 

 blackish brown, with dense gray pruinose markings, as follows: A slen- 

 der median stripe obsolete behind; a large spot in front of the scutel- 

 lum, slenderly prolonged on its anterior angles to the middle of the 

 dorsum, the humeri, a spot on their inner sides, another large one 

 behind, concave on its inner border, and a smaller one on the post- 

 alar callosities. Pleurae gray pruinose; the fan-like fringe of hairs in 

 front of the halteres black. Abdomen with white pile on the sides in 

 front; the last two segments wholly polished. Anterior and interme- 

 diate coxae, and all the femora below towards the base with long soft 

 white pile; anterior tibiae on their inner sides and their metatarsi with 

 golden pubescence; posterior tibiae at their tip and the tip of their 

 metatarsi with white pubescence ; femora black ; tibiae and tarsi red; 

 the latter more brownish-red. Wings hyaline in the basal half, dis- 

 tinctly clouded with brownish on the distal half; the veins from the 

 margin of the second longitudinal to the beginning of the posterior 

 basal transverse narrowly but distinctly clouded with brown; the 

 veins at the base of the second submarginal and the first and second 

 posterior cells less distinctly clouded." 



Type. — University of Kansas. One female specimen. 

 Habitat. — Mt. Hood, Oregon (type). 



Cyrtopogon niaculosis. 



Cyrtopogon maculosis Coquillett, Proc. Ent. Soc, Wa.sh., VI, 



184, 1904. 



" 9 . — Length 10 mm. — Near rejectus, but the wings distinctly spotted, 



thorax with a crest of hairs, etc. Black, including the halteres. Face 



strongly gibbose; mystax black, rather dense, mounting nearly to the 



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



