324 U. S. NATIONAL MUSEUM BULLETIN 216 



Black. Palpi of male, nearly always a spot of variable size on 

 front of scape of male, sometimes scutellum of male, hind corner of 

 pronotum of male, and tegula of male, white or whitish; palpi of 

 female fuscous; scape, scutellum, hind corner of pronotum, and teg- 

 ula of female black; legs fulvous, the hind tibia and tarsus blackish, 

 the tibia almost always with a submedian pale band. The apex of 

 the hind femur is often fuscous. Wings hyaline. 



This is a Holarctic species, with two subspecies in North America 

 and two in Eurasia. Of the two North American subspecies, typ- 

 ical aquilonius occurs east of the Rocky Mountains and the sub- 

 species exareolatus from the Rocky Mountains westward. Alaskan 

 populations tend to be intermediate but the majority of them seem 

 assignable to the subspecies aquilonius. For example: a series from 

 Naknek, Alaska, and another from King Salmon on the Naknek 

 River, Alaska (both series in Ottawa), contain specimens assignable 

 to the subspecies aquilonius, some intermediate specimens, and a few 

 assignable to exareolatus. The type series of yakutatensis, from Yaku- 

 tat Bay, Alaska, is also intermediate. In Europe there is the sub- 

 species C. aquilonius Jlavicoxis (Thomson) 1877 (new status), which 

 is intermediate in leg color between the two American subspecies 

 and perhaps not distinguishable from the Alaskan population. There 

 is also an undescribed subspecies in Japan, with the apex of the hind 

 femur extensively infuscate. We have a series of it from Sapporo. 



The American subspecies are keyed below: 



1. Apical 0.05 or less of hind femur fuscous (fig. 327,a) ; pale band on hind tibia 

 grayish or brownish white, occupying about 0.20 the length of the tibia; 

 range: Rocky Mountains to Pacific, and part of Alaska. 



5a. aquilonius exareolatus (Ashmead) 



Apical 0.15± of hind femur fuscous (fig. 327, b) ; pale band on hind tibia 



whitish, occupying about 0.23 the length of the tibia; range: east of Rocky 



Mountains and part of Alaska . . . 5b. aquilonius aquilonius (Cresson) 



5a. Coccygomimus aquilonius exareolatus (Ashmead) 



Figure 327,a 



Itoplectis exareolatus Ashmead, 1901, Psyche, vol. 9, p. 147; 9 • Type: 9 , 



Las Vegas Range between Pecos and Sapella Rivers, 11,000 ft., N. Mex. 



(Washington). 

 Pimpla yakutatensis Ashmead, 1902, Proc. Washington Acad. Sci., vol. 4, p. 200; 



cf. Lectotype (hereby selected): cf, labeled "type" by Ashmead, Yakutat, 



Alaska, June 21, 1899, T. Kincaid (Washington). 



Male usually but not always with some white on front of scape; 

 hind femur with very little fuscous on its apex, sometimes with none; 

 pale band on hind tibia grayish white or brownish white, occupying 

 about 0.20 the length of the tibia, sometimes narrower or rarely absent. 



Specimens (187 d 1 , 749): From Alberta (Vermillion Lake near Banff 

 at 4,500 ft.) ; Alaska (Anchorage, Cold Bay at 163° W., Popoff Island, 



