SuBFAMILY CALLIPHORINAE 995 
ginal row of bristles, the fourth segment with scattered long 
erect discal bristles. 
Genital segments with forceps (pl. 26, B) as illustrated. 
Female. Unknown. 
Length. 7-8 mm. 
Type. Male, No. 54931, U. S. National Museum. 
Type locality. Tennessee Pass, Colo. 
Three male specimens, the type, collected July 12, at 10,240 
feet elevation by J. M. Aldrich, one paratype, collected August 
28, at Brainard Lake, Colo., by T. D. A. Cockerell, previously 
determined as Acrophaga alpina (Zett.), and one paratype, col- 
lected in August 1924, in Pingree Park, Colo., by Paul Lawson 
and Raymond Beamer. 
Acrophaga alpina (Zetterstedt), a species which occurs in 
northern Europe, has but one posterior bristle on the anterior 
tibia. As previously stated, North American species, originally 
placed in the genus Acrophaga, lack a tuft of hair on the tym- 
panic pit. Acrophaga stelviana Brauer and Bergenstamm also 
differs from this species in having four well-defined lateral scu- 
tellar bristles. 
Biology, habits, and rmmature stages. Unknown. 
Acronesia alaskensis (Shannon), new combination 
Steringomyia alaskensis Shannon, Insecutor Inscitiae Menstruus 
11:112, 1923; Séguy, Eneyel. Ent. (A) 9:122, 1928. (Type, 
male from Seward, Alaska, No. 26164, U. S. National 
Museum. ) 
Male. Head height 11.1; width 13.2; eye height 7.9; length at 
antenna 6.5 and at vibrissa 6.6; bucca 0.39 eye height, black, 
with coarse gray pollen and with black hair; front black, with 
silvery gray pollen, at narrowest 0.05 head width, 0.17 at vertex 
and 0.27 at lunule, with a few black hairs outside frontal row 
of bristles; vertex black, silvery; ocellar triangle with a number 
of long erect black hairs; frontal bristles about six, those toward 
lunule strong, the row continuing with a number of rather erect 
hairs toward vertex; parafaciale black with bright silvery pollen 
and with a few scattered black setae on upper third, 1.5 in width 
opposite lunule and a little wider below; faciale orange to orange 
brown, with a double row of short dark brown setae which ascend 
nearly one-half the distance from the vibrissa to the antennal 
base; vibrissae set 2.9 apart; elypeus dark brown to black; epis- 
toma orange; first and second antennal segments orange brown, 
the latter lighter orange apically; third segment 3.7 times as 
