4 Everett E. Wehr 



the posterior margin of the first segment; the venter pale yellow except 

 for a black area in the apex of the second segment; both dorsal ' 

 and ventral aspects covered with black hairs. Wings hyaline with costa 

 and stigma yellow; a stump on the anterior branch of the third vein. 

 Legs yellow with the last four tarsi dark, the apical half of the tibiae and 

 tarsus heavily beset with black hairs. 



Type. Ute Creek, Costilla County, Colorado, on sage flats, 

 August 7, 1907 (R. W. Dawson) . Two $ $ , type and paratype. 

 University of Nebraska collection. Compared with gigantu- 

 lus 9 5 from Truckee, California, August 4, 1914 (L. Bru- 

 ner), also in the University of Nebraska collection. 



Silvius quadrivittatus Say. Jr. Acad. Nat. Sci. Phil., iii, 33 (1823); 

 Compl. Writ., ii, 54 (1859); Hine, Ohio Naturalist, v. No. 2, 229 

 (1904). 



Common over the entire state of Nebraska. One s and 

 eighty-three 9 $ f rom South Bend, Cass County; Louisville 

 Cass County; Lincoln, Lancaster County; Ashland, Saunders 

 County; South Sioux City, Dakota County; McCook, Red- 

 willow County, Culbertson, Hitchcock County, and Haigler, 

 Dundy County, June 14th to September 3rd. 



Silvius pollinosus Williston. Tr. Conn. Acad. Sci., iv, 224 (1879). 



A 9 specimen from McCook, Redwillow County, June 20, 

 1913 (R. W. Dawson), establishes the place of this species in 

 the Nebraska fauna. 



Chrysops Meigen 



There are specimens of nine species of this genus collected 

 in Nebraska represented in the University of Nebraska col- 

 lection. Of these, the males of five species are available for 

 study. I offer the following key as an aid in separating the 

 species : 



1. Apex of the wing beyond the cross-band hyaline; body uniformly 

 black; thorax on each side with a tuft of yellow hair at root of 

 wings; length ?, 8-9 mm carbonarius 



110 



