[443] DIPTERA 57 



Sitka, June 16; Virgin Bay, June 21 ; Kukak Bay, July 4; Popof 

 Island, July 8 to 14; Kadiak, July 20; Saldovia, Alaska, July 21 : 

 Fifty-five specimens of both sexes. The type locality of this species 

 is Alaska. 



Hyetodesia villicrura sp. nov. 



Male: Black, the halteres brown; hair of eyes long and dense, 

 frontal vitta at narrowest point narrower than the lowest ocellus, an- 

 tennae three-fourths as long as the face, the third joint one and one- 

 half times as long as the second, a white pruinose spot between bases 

 of antennae, arista long pubescent, the longest slightly more than 

 greatest diameter of the arista ; mesonotum polished, not gray pruinose 

 except on the sides, four pairs of postsutural dorsocentral bristles, 

 sternopleurals i -f 2 ; abdomen narrowly subovate, slightly over twice 

 as long as wide, polished, thinly olive gray pruinose, the greater por- 

 tion of the first segment and a dorsal, indistinct, subtriangular spot on 

 the second and third, blackish, hypopygium only slightly projecting; 

 front tibias short haired on the lower half of its inner side, inter- 

 spersed with about three long and four shorter bristly hairs ; middle 

 femora densely long haired on the basal two-thirds of the under side, 

 their tibiae each bearing about five bristles along the outer-posterior 

 side and with about six bristles and a few shorter bristly hairs on the 

 lower two-thirds of the inner-posterior side ; hind femora densely long 

 haired on the under side, their tibiae with similar hairs along the inner, 

 anterior-inner, and posterior-inner sides, the outer side ciliate with 

 rather short bristly hairs interspersed with about four longer bristles 

 on the lower two-thirds; wings pale brownish, changing into grayish 

 hyaline along the hind margin, nearly wholly hyaline in the younger 

 specimens, costal spine minute, third and fourth veins diverging, hind 

 crossvein almost straight; calypteres yellowish white, the lower ex- 

 tending far beyond the upper. 



Female: Differs from the male as follows: Halteres yellow, eyes 

 bare, front at narrowest point slightly narrower than either eye, a prae- 

 ocellar, cruciate pair of bristles present; mesonotum opaque, yellow- 

 ish gray pruinose ; abdomen subovate, slightly polished, grayish yel- 

 low pruinose, unmarked; front tibiae destitute of bristles except at the 

 apices, middle femora sparsely short haired on the under side, their tibiae 

 pubescent on the inner-posterior side but with two or three bristles on 

 lower half of the outer-anterior side ; hind femora bearing five or six 

 bristles on the apical half of the under side, and sometimes with a few 

 long hairs on the basal portion ; hind tibiae pubescent, each bearing 



