300 THE BLOWFLIES oF NortH AMERICA 
frontale at lunule; frontal bristles thin, hair-like, and numerous 
toward vertex, which is black with gray pollen; front black, with 
heavy gray pollen, thickly setose at narrowest where it is 0.4 
of head width, 0.13 at vertex and 0.28 at lunule; carina low but 
apparent; parafaciale black, with thin gray pollen, 1.8 in width 
opposite lunule and wider below; faciale orange red with several 
rows of short black setae which ascend fully four-fifths the dis- 
tance to the antennal base; palpus orange, 4.0 in length; apical 
portion of second and basal portion of third antennal sezments 
red orange, otherwise dark brown to black; third segment of 
antenna 3.7 times as long as second, reaching slightly more than 
two-thirds the distance to the vibrissae, which are above the 
oral margin and 3.1 apart; back of head black, silvery, with three 
or four rows of postocular cilia and considerable yellowish or 
tawny hair. 
Thorax black, with pollen apparent only in favorable lights 
on prothorax behind head, and- with dorsal longitudinal stripes 
indistinct; hindmost acrostichal, dorsocentral and intraalar bris- 
tles before the suture by 2.0, 1.2, and 0.8 respectively; sclerites 
at wing base black; spiracles with yellowish brown hair; scutellum 
with five lateral bristles, the intermediate ones weak. 
Legs like vomitoria and vicina except middle tibia usually 
with two anterodorsal and two posterior bristles. 
Wing brownish; subcostal sclerite orange brown; basicosta 
black; costal sections 2 to 6 in the proportion 85:55:110:40:8; 
squamal lobes tinged with dark brown, shaded as in vicina. 
Abdomen deep purplish blue, with whitish pollen, the hind 
margin of the segments mostly shining. 
Genital segments small, black, with abundant thin black hair; 
outer forceps thick at base but gradually tapering to a narrow 
apex; inner forceps long and thin, the inner margins not diver- 
gent. 
Female. Head height 11.4; eye height 7.4; bucca 0.44 of eye 
height; length at antenna 6.8 and at vibrissa 7.7; parafaciale 
opposite lunule 1.9; vibrissae set 3.6 apart; head width 14.5; 
front at narrowest (at vertex) 0.34 head width, 0.39 at lunule; 
palpus 4.5 in length; third segment of antenna 5.5 times as 
long as second. Wing with costal sections 2 to 6 in the propor- 
tion 90 :60 :142 :50:6. Otherwise similar to male except for normal 
sexual differences. 
Length. 5-8 mm. 
Distribution. Nearctic: Alaska. 
In addition to the type series mentioned by Shannon, the Na- 
tional Collection contains 2 females and 10 males collected July 
