252 U. S. NATIONAL MUSEUM BULLETIN 216 part 3 



Male: Colored like the male of the subspecies argentifrons except 

 that the hind femur is ferruginous. The white markings average a 

 little more extensive than in argentifrons, the hind tibia and basitar- 

 sus vary from fuscous to fulvous, and the front and middle legs be- 

 yond the first trochanters average paler. Sometimes the front and 

 middle legs are rather uniformly fulvous, without the front of the 

 front femur and upper side of front and middle tibiae being definitely 

 whitish. The hind basitarsus is not white apically, or only its ex- 

 treme tip is whitish. 



Female: Black. Orbit with a narrow whitish stripe in front and 

 behind ; median part of clypeus and front edge of mandible sometimes 

 whitish; front and middle femora varying from fulvoferruginous to 

 mostly fuscous, most of front part of front femur and middle femur 

 apically in front, fulvous or brown; front and middle tibiae and tarsi 

 brownish fulvous to brown; hind tibia and tarsus brown to fuscous; 

 wings moderately to strongly infuscate; abdomen red, the basal haU 

 of its first segment sometimes partly infuscate. 



Intergrades between this subspecies and rufovindus or between it 

 and argentifrons are not scarce. Most of the intergrades are from 

 British Columbia and Idaho, where the range of mutatus overlaps 

 those of rvjomndus and argentifrons. The intergrades have been 

 classified with one of the three subspecies involved according to which 

 of the three they resemble most closely. Thus a specimen with the 

 hind femur red and the hind coxa mostly red but partly black is clas- 

 sified as the subspecies rufovindus, and one with the hind coxa black 

 and the hind femur fuscoferruginous, but more ferruginous than 

 fuscous, is classified as the subspecies mutatus. 



Specimens (27 cf, 129): From Alberta (Waterton); British Colum- 

 bia (Atlin at 2,200 ft., Kaslo, Robson, and Vernon); California (Big 

 Flat on Coffee Creek in Trinity Co., Crane Flat in Yosemite National 

 Park, Dardanelle, Mammoth Lake in Mono Co., May Lake in Yosem- 

 ite National Park, Mount Tallac near Lake Tahoe, and Snow Flat in 

 Yosemite National Park); Colorado (Steamboat Springs); Idaho 

 (American Falls, Bancroft at 5,423 ft., Hansen, 5 miles north of 

 Hazelton, 3 miles west of Juliaetta, Lewiston, Moscow, and Rupert 

 at 4,157 ft.); Nevada (Caliente); South Dakota (Brookings); and 

 Washington (Mount Rainier at 5,300 ft. and Pullman). 



Collection dates are mostly from June 15 to August 10. Those 

 outside of this range are: April 21 three miles west of Juliaetta, Idaho; 

 May 21 on Coffee Creek, Big Flat, Trinity Co., Calif.; May 23 at 

 Robson, B.C.; August 17 on Mount Rainier, 5,300 ft.. Wash.; and 

 August 18 at Rupert, 4,157 ft., Idaho. 



This subspecies occurs mostly in the northwest corner of the United 

 States and adjacent Canada. Specimens of it, however, are known 



