186 ERNEST A. BACK. 



Habitat. — Squaw Creek, Wash.; Lombard, Mont. (June 

 26, elev. 4,000 ft., R. A. Cooley) ; Snake Co., Idaho; Sioux Co. 

 (P. R. Jones), Nebr. ; Ft. Collins (July 17, 29), Colorado Springs 

 and Spanish Peaks, Col.; Garden City, Ks. (July); N. M.; 

 Round Mts., Tex.; Car Canyon, Huachuca Mts., Cochise Co., 

 Ariz. (Aug., H. Skinner); Cal. 



Judging from its presence in many collections, this seems 

 to be a common species throughout our western and south- 

 western States. In both sexes the red of the second segment 

 of the abdomen is variable in extent and often extends over 

 the anterior portion of the sixth segment in the female. One 

 male has no red on the second segment and only a little on the 

 anterior margin of the seventh. Several specimens from Prof. 

 R. A. Cooley, of Bozeman, Montana, have the tergum much 

 deeper red than most of the specimens which I have seen. 



Osi>rioeerus eutrophus. 



Ospriocerus eutrophus Loew, Berl. Ent. Zeit., 1874, 355. 

 Ospriocerus eutrophus Howard, Insect Book, 1902; PI. XIX, 



fig. 9. 

 Ospriocerus eutrophus West. Dipt., 1877, 290. 



9- — Length 21.5-22 mm. — Black, thorax usually of a dark chocolate 

 color. Face, excepting the gibbosity and a triangular area above with 

 its apex at the base of the antennae, wholly white pruinose. Posterior 

 portion of the second abdominal segment, and the three following 

 segments, excepting their lateral margins, red or yellowish-red; the 

 remainder of the abdomen black; posterior lateral margins of the sec- 

 ond, third and fourth segments white pruinose. Legs black, the front 

 tibiae, together with the first segment of their tarsi, with compact 

 glistening pile. Wings black. All the bristles of the body and legs 

 black. 



Type. — M. C. Z. Three female specimens. 



Habitat. — Texas; Kansas. 



This species resembles abdominalis but the larger size pro- 

 portionately smaller, and at its' end, slender, abdomen and the 

 white pruinose lateral margins of the second, third and fourth 

 abdominal segments of eutrophus readily separate them. Of 

 the three females in Loew's collection, one specimen has the 

 thorax dead black, and so accords with the original description. 

 The thorax of the other two, and also of other specimens 

 which I have seen, is a dark brown, which gives to these 



