SUBFAMILY CALLIPHORINAE 279 
Genital segments(pl. 26, F and G) as illustrated. 
Female. Head height 9.5; width 10.0; length at antenna and 
at vibrissa 5.6; eye height 6.0; bueca 0.41 of eye height; para- 
faciale opposite lunule 1.6 in width; distance between vibrissae 
2.6; frontale 0.60 frontal width, reddish brown anteriorly, darker — 
posteriorly; frontal bristles six, all strong; front at narrowest 0.40 
head width, the margins only slightly diverging to 0.42 of head 
width at lunule; third segment of antenna 3.8 times as long as 
second. Wing with costal sections 2 to 6 in the proportion 
70:48: 120:40: 6. Otherwise similar to male ere for normal 
sexual differences. 
Length. T-8 mm. 
Type. Male, No. 54932, U. S. National Museum. 
Type locality. Savonoski, Naknek Lake, Alaska. 
The type, three paratype males, and two paratype females are 
from the type locality; two paratype males are from Katmai, 
Alaska. These were collected during the summer of 1917 by the 
late J. S. Hine. 
Biology, habits, and wmmature stages. Unknown. 
Acronesia collini, new species 
Steringomyta popoffana Collin (nee Townsend), Ann. and Mag. 
Nat. Hist. (10) 15 :3873-374, 1935. (Type, male from Akpotok 
Island, Ungava Bay, Canada, in the Collin Collection at 
Newmarket, England.) 
Male. ‘‘Rather smaller than females, eyes rather BR sep- 
arated on frons, at narrowest quite as wide as facial orbits at 
base of antennae, and quite 1/3 width of one eye seen from 
above. Frons with a complete row of almost equally long bristles 
each side from opposite ocellar bristles to frontal lunule. Arista 
thickened on more than basal half, .pubescence very short at 
base, becoming longer toward end of thickened part. Labium 
polished black. Thorax with usual chaetotaxy; intra-alars 2:2 
without a small additional one in front of anterior one; sterno- 
pleurals 2:1. Abdomen with rather strong, outstanding bristles 
across hind margin of apparent second tergite and discal as 
well as marginal bristles on third and fourth tergites (but dis- 
eal ones on third not so strong as on fourth). Sternites densely 
clothed with long black bristly hairs, but shorter on the not 
very prominent lobes of fifth sternite. Second sternite about as 
long as broad, in female distinctly longer than broad. Hypo- 
pygium comparatively small, prehypopygial tergite concealed 
