278 THE BLOWFLIES oF NortH AMERICA 
tween vibrissae 3.3; frontale velvety black, often slightly orange 
brown at lunule, fully 0.70 of frontal width toward middle; back 
of head rounded. Wing with costal sections 2 to 6 in the propor- 
tion 85: 65:1387:47:10. Otherwise similar to male except for 
normal sexual differences. 
Length. 7-9mm. _ 
Distribution. Nearctic Alaska (June to August); British 
Columbia, ‘‘Canada’’ (July); Quebec, (August) ; Colorado; Wy- 
oming; Montana (August); Washington. 
Biology, habits, and immature stages. One female in the col- 
lection has a first-instar larva protruding from the tip of the 
abdomen; the species may be larviparous, but nothing definite 
is known of the biology of the species. 
Acronesia anana, new species 
Steringomyia alpina Shannon (nee Zetterstedt) (in part), In- 
secutor Inscitiae Menstruus 11:111, 1923. 
Male. Head width 11:5; height 10.0; eye height 6.5; length 
at antenna 6.7 and at vibrissa 7.1; bucca 0.47 eye height, black, 
with black hair, no pale hair before the metacephalic suture, 
with thin gray pollen; frontale as wide as parafrontale at nar- 
rowest, brownish; front at narrowest 17.5 head width, 0.30 at 
vertex and lunule, black, with silvery pollen and with a few 
weak hairs outside frontal row of bristles; frontal bristles about 
10, the rows moderately diverging anteriorly as they follow the 
margins of the frontalia, and extending anteriorly to the lunule; 
parafaciale 1.8 in width opposite lunule, black on upper half 
and orange below, with silvery pollen which has a slight brassy 
tinge, upper half with a few minute black setulae; faciale, lower 
half of clypeus, and epistoma orange; vibrissae set 2.8 apart; 
palpus orange, 4.0 in length; antenna with basal segments orange 
to orange brown; third segment 3.5 times as long as second, 
orange basally, dark brown apically; arista black with medium- 
length. black cilia for two-thirds its length; back of head black, 
with silvery pollen, with at least five rows of postocular cilia and 
a few light hairs on the metacephalon. 
Thorax colored and bristled like abina except with the hind- 
most preintraalar bristle present; hindmost preacrostichal bristle 
placed 2.7 before the suture. 
Wing with costal sections 2 to 6 in the proportion 77:50: 120: 
40:7; brownish; rim of upper squamal lobe orange brown. 
Legs and abdomen like abina, 
