SuBFAMILY CALLIPHORINAE arg k 
than in male; bucea 0.27 of eye height; frontale 0.60 frontal width 
at ocellar triangle but narrowing toward lunule to 0.5 of front, 
dark reddish brown anteriorly, black posteriorly; frontal bristles 
eight, the rows sharply divergent in the foremost bristles; para- 
frontale with silvery pollen over dark reddish to almost black 
ground color, and with several scattered and one well-defined 
row of small black setae outside frontal row; parafaciale dark 
reddish, with silvery pollen, 1.3 in width opposite lunule; vertex 
mostly black with thin whitish pollen and only slightly greenish; 
back of head with almost entirely black hair but with tawny hair 
around occiput and on metacephalon. Thorax usually more 
bluish than in male, with stronger purplish reflections and with 
more whitish pollen on prothorax between humeri. Wing with 
costal sections 2 to 6 in the proportion 73:46 :96:43:7; squamal 
lobes more whitish than in male. Abdomen colored as in male 
but first segment metallic, second segment with marginal bristles 
recumbent but still elongate, the middle pair or two considerably 
longer than the laterals. Otherwise similar to male except for 
normal sexual differences. 
Length. 6-9 mm. 
Distribution. Nearctic: United States, Idaho. 
Phaemcia thatuna is clearly related to sericata. The entire 
series at the National Museum was collected in an area a com- 
paratively few miles in extent, on July 20 to July 27, over a 
period of about 10 years by the late J. M. Aldrich. Six speci- 
mens are from the type locality (Mt. Moscow), two specimens 
are from Lake Waha, three are from Gold Hill, Latah Co., and 
two are from Craig Mt., Nez Perce Co., all Idaho. The species 
- appears to be decidedly local in distribution, occurring at an 
elevation of from 4,000 to 5,000 feet in the mountains of north- 
western Idaho. j 
Biology, habits, and immature stages. Unknown. 
TRIBE CALLIPHORINI 
(The bluebottle flies) 
All North American representatives of this tribe (Color plate, 
IV) possess the following characters in common. 
Male and female. Head (pl. 5, D) with epistoma elongate, 
nearly as wide as clypeus, and warped forward from clypeal 
plane, often strongly so; frontal bristles often extending to 
middle of second antennal segment, the rows widely diverging 
anteriorly; parafaciale setose on upper third or more; vibrissae 
strong and at or but slightly above the oral margin; palpus 
