AMERICAN DIPTERA. 201 



Length of body 13-14 lin., of wing 9 lin. — Grayish, opaque. Mystax 

 and pile of entire head straw-colored. Antennae black. Thoracic 

 dorsum with vittas hardly obsolete, clothed with very short nigro- 

 fuscous pile and straw-colored setae; humeri brown, whitish pruinose. 

 Abdomen blackish-gray, toward the apex black and polished, clothed 

 with short straw-colored or whitish pile, resupinate on the last two 

 segments. Legs grayish-black, knees and tarsi brown, with many 

 bristles; the bristles of the tibise and tarsi for the most part black. 

 Wings equally fuscous, veins dark brown, fourth posterior cell open. 



Type.—M. C. Z. 



Habitat. — Red River of the North, Minn. 

 The above description means very Httle, but lack of ma- 

 terial forces me to use it. 



Steiiopo^oii tciicidiuus. 



Stenopogon csacidinus Williston, Trans. Am. Ent. Soc, XIII, 



289, 1886. 

 Stenopogon asacidiniis Jones, Trans. Am. Ent. Soc, XXXIII, 

 274, 1907 (note). 

 ■^ ?. — Length 14-20 mm. — Black; abdomen, except base, hypo- 

 pygium of male, and the last two segments of female, yellowish-red; 

 wings black; mystax white. Hypopleurae with fine short hair. 



"Like species of Ospriocerus, but the antenna2 with a distinct 

 terminal style. Face wholly densely grayish-white pruinose, the 

 bristles of the mystax white; frontal and occipito-orbital bristles black; 

 beard and long hair of the anterior coxae white. Dorsum of thorax 

 moderately polished, brownish-black, on the sides grayish or brownish- 

 yellow pruinose, behind and on the scutellum less thickly so, in the 

 middle with not very noticeable stripes. Abdomen slender, yellowish - 

 red, the first, second and anterior angles of the third segment and the 

 hypopygiuin black. Legs black, the fore femora more or less, the fore 

 and middle tibiae and tarsi, pitchy or reddish. Wings black." 



Type. — University of Kansas. Three male specimens. 



Hatabit. — Kansas Plains, in grassy ravine, Aug. 20 (type) ; 

 Garden City, Ks. (Aug., H. W. Menke) ; Bear Cr. Caiion (July 

 5-8) and Denver (Osten Sacken), Col.; Lincoln Nebr. (July). 



I have seen about twenty specimens of this species, and 

 they all agree very well with the above description. The 

 female is like the male except that the last two, and some- 

 times the last three, segments of the abdomen, are polished 

 black. The frontal bristles appear to be uniformly black, but 

 the occipito-orbital ones are as frequently black as they are 



TRANS. AM. ENT. SOC, XXXV. (26) JUNE, 1909. 



