THE CANADIAN ENTOMOLOGIST 27 



Male. — Length 5 mm. ; wing 5.2 mm. 



Rostrum and palpi brown. Antennae with the first segment 

 yellowish; remainder of the antennae dark brownish black, the 

 flagellar segments short-cylindrical. Head broad, light yellow, 

 palest on the front, richer on the vertex and occiput; a dark brown 

 linear mark on the head. 



Mesonctal pracscutum light yellow, with three very broad, 

 dark brown stripes that are confluent behind, the middle stripe 

 ending before the transverse suture; tuberculate pits at nearly mid- 

 length of the sclerite, rather linear, separated by a distance equal 

 to nearly twice the short diameter of one; scutum light yellow, the 

 lobes largely dark brown, this consisting of two confluent blotches; 

 scutellum light yellow, broadly dark brown 'medially, broadest 

 anteriorly postnotum yellowish basally, brown caudally. Pleura 

 yellow with two indistinct and somewhat interrupted lateral stripes, 

 the dorsal one passing above the root of the halteres, the ventral 

 one inclifding the sides of the sternum; sternum yellow, except the 

 sides and a narrow, dark brown, median line on the mesasternum ; 

 dorso-pleural membranes dusky. Haltsres yellow. Legs with 

 the coxae and trochanters light yellow; remainder of the legs broken. 

 Wings broad, the anal angle prominent; membrane light gray with 

 srrall, grayish brown spots as follows: At the origin of Rs, at r, 

 tip of Ri, fork of Rs, along the cord and outer end of cell 1st Mt; 

 \eins dark brown. Venation: Sa far removed from the tip of 

 Sa, lying just distad of the origin oi Rs; r lying far from the tip 

 cf Ri, this distance equal to about one-half of Rs; cell 1st Mt closed, 

 narrowed at its inner end; basal deflection of Cui far before the 

 fork of M; second anal slightly bisinuate. 



Abdominal tergites dull yellow, more brownish basally, a dark 

 brown median blotch on each segment; sternites dull yellow, dark 

 brown medially, the apical segments clearer yellow. Hypopygium 

 with two broad, flattened lobes under the 9th tergite, these heavily 

 chitinized on their dorsal edges; pleurites long, slender, somewhat 

 digitiform; appendages black. 



Habitat. — Utah. 



Holotype, d" , mouth of Bear River, Utah; Sept. 16, 1914 (A. 

 Wetmore). 



Type in the collection of the L^^nited States Biological Survey. 



