446 PROCEEDINGS OF THE NATIONAL MUSEUM. voi.xxiii. 



except sometimes in the infusoations of the veins of the area usually 

 occupied by the l>and; hyaliii(\ with the base very faintly tinged with 

 blue, or greenish; dividing vein of the second anal uniting with the 

 second anal one-third the length of the latter from the base. Posterior 

 femora with the disk of the inner face black with two light bands on 

 the apical half; lower sulcus black or more or less inf uscated with two 

 light bands on its apical half. Posterior tibiae never red nor blue, 

 yellowish or obscure. 



TRIMEROTROPIS AZURESCENS Bruner. 



D-imerotropis azurescens Bruner, Proc. U. S. Xat. Mils., XII, 1890, p. 69. 

 Trimerotropis perplexa Bruxer, Proe. U. S. Nat. Mus., XII, 1890, p. 74. 



Size medium; color varying from grayish-white to dull brown, 

 much but not conspicuously varied with fuscous. 



Frontal costa sulcate for a considerable distance above the ocellus; 

 scutellum of the vertex only moderatelj^ (female) or deeply (male) sul- 

 cate, a little (female) or much longer (male) than wide, with the 

 median carina distinct though slight; eyes plainh' shorter than the 

 genal groove. Pronotum with the median carina low, even upon 

 the prozone, and liarely cristate; posterior lobe of the crest of the 

 prozone conspicuously longer than the posterior lobe; lateral carinje 

 entirely wanting on the metazone and scarce!;/ visible on the anterior 

 part of the prozone: metazone finely granulate without larger scat- 

 tered granulations, nearly twice as long as the prozone, with its 

 process acute angular, sides straight, and tip slightly rounded. Teg- 

 mina much varied, with slightly contrasting, not very dark, annular 

 spots, which are very imperfecth^ segregated into the three bands 

 typical of the genus; area of the cubital fork in the male occupied by a 

 single series of cells, at least at the base in the male; this area very 

 variable in the female. Wings broad, but much more decidedlj^ in 

 the females; in the former scarcely, in the latter inWy two- thirds as 

 long as broad; hyaline, faintly tinged with blue or greenish, especially 

 on the anal portion of the radiate held, with fuscous band only faintly 

 indicated in some specimens by infuscation of the veins. Posterior 

 femora plain on the outer face or very inconspicuously banded. 

 Posterior tibiae obscure yellow, with indehnite brownish clouds on the 

 basal half and apically. 



Length of body, male. '2'2 mm,, female, 29 mm.; length of teg- 

 mina, male, 24 mm., female, 30 mm,; length of posterior femora, 

 male, 12 mm., female, 14 mm. 



IlaVdat. — Fort Benton, Montana, United States National Park, 

 Wyoming, Lemhi or Salmon Kiver, Idaho; Chadron, Nebraska, 

 Bruner; Alkali Stage Station, Green River, Wyoming, Scudder. I 

 hav<^ seen specimens of aznre^cfn^ from Fort Benton, Montana, and 

 Salmon City, Idaho, from Doctor Bruuer's collection, also Bruners 



