AMERICAN DIPTERA. 199 



tennae, and often the third segment and style in varying degree, 

 reddish. Abdomen brick-red, polished, lateral margins of all the 

 segments broadly black, but usually not showing from above in dried 

 specimens; posterior lateral margins whitish pruinose; genitalia of 

 male red. Bristles of body pale straw-colored, except those of basal 

 segments of antennas, humeri, abdomen and legs, which are more 

 reddish; hair of thoracic dorsum very short throughout and black. 

 Legs yellowish-red, the femora above, except at apices, black; claws 

 black, yellow at base, pulvilli pale. Wings throughout tinged with 

 fuscous; the first and fourth posterior cells open or closed, showing 

 considerable variation in this respect. 



Type.—U. C. Z. 



Habitat. — Nebr. (type) ; Glen, Sioux Co., Springview Bridge, 

 Brown Co., West Point, Nebr.; Vernon, B. C. (July 24). 



Stenopogoii niorosiis. 



Stenopogon ntorosus Loew, Berl. Ent. Zeit., 1874, 356. 



(^ 9- — Length 21.5-37 mm. — Translation. — ^Black, lightly sprinkled 

 with grayish bloom; apex of the femora, the tibise and the tarsi piceus, 

 rarely nigro-piceus, of the front tarsi sometimes reddish; the first two 

 segments of the antennae and the front with black hair, nearly all the 

 bristles of the femora black; the wings wholly blackish-gray. Male 

 abdomen black, the last two segments and the hypopleurae for the inost 

 part reddish. Female abdomen ornamented with a very broad red 

 vitta, or sometimes wholly black. 



A very variable species, of which I have had the opportunity of 

 examining three males and four females; so much like fnodestus that 

 I was at first inclined to consider it as a variety of that species, but 

 all the specimens are somewhat sinaller and of less robust body struc- 

 ture; the whitish bloom is also much thinner everywhere, so that the 

 black ground color of the body is very little modified when seen 

 through the bloom. The four females are distinguished from the 

 females of modesttis in the following respects: — (1) The first two an- 

 tennal segments are conspicuously, or at least quite noticeably, covered 

 with black hair, whereas in modestus they are conspicuously clothed 

 with white hair; (2) the hair of the whole front is black, while in 

 modestus it is black only on the ocellar tubercle, but otherwise white; 

 (3) the abdomen in all four females has a broad red longitudinal 

 stripe, while that of modestus has only a small trace of reddish color; 

 the bristles of the femora are, practically without exception, black, 

 although on the anterior side of the middle femora of one specimen 

 there are a large number of pale yellowish ones intermixed, while in 

 modestus the bristles on the femora are pale yellowish or yellowish- 

 white, with only here and there a black one. 



TR.^NS. AM. ENT. SOC, XXXV. JUNE, 1909. 



