294 AMERICAN HYMENOPTERA. 



the yellow pile very light, in some cases almost white, and 

 many times the pile on the abdomen which is normally ferru- 

 ginous is also very nearly white. The workers and males 

 usually have the yellow and ferruginous much deeper and 

 more pronounced than in the queens. 



Habitat. — A strictly Boreal form. The writer has records 

 from New Mexico (Truchas Peak), Colorado, Montana, 

 Oregon (Mt. Hood), Labrador, Boothia Felix, Hudson's 

 Straits, Hudson Bay Territory, Alberta, British Columbia, 

 and Southern Alaska (BartlettBay at sea-level), and there is 

 a queen before me from Sopka, Siberia. Aurivillius has 

 reported it from Greenland (Polaris Bay, Port Foulke, God- 

 haven, Auleitsivik and Inigtut). In the western United 

 States and southwestern Canada, it is confined to the highest 

 ranges of the Rocky Mountains. In no part of its habitat 

 in North America does it appear to be a common species. 

 It may be present in northern Europe and, if so, B. balteatus 

 Dahlbom may be the same species. Most of the descrip- 

 tions, reference to which is made, in Dalla Torre's catalogue, 

 under the names balteattis and nivalis, cannot be made to 

 apply satisfactorily to this insect, as they describe the thoracic 

 pleura as covered largely with dark pile. Aurivillius gives a 

 very accurate description of true kirbyelhis and its variations 

 from Greenland specimens and states that the Greenland 

 specimens differ from European ones. 



This species is evidently most closely allied to B. kincaidii 

 Cockerell and its next nearest relatives appear to be B.polaris 

 Kirby and B. arcticus Kirby. 



In a paper published in Ann. du Mus. Zool. de I'Acad. 

 Imp. des Sci. de St. Petersbourg, 1904, Tome IX, No. 4, H. 

 Friese describes a new variety and a new subspecies of this 

 species as follows : 



" B. kirbyellus Curt. var. lysholmin. var.— Entirely black, only seg- 

 ments four to six white haired. Subsp. pyropygus Friese — segments 

 four to six red haired." 



I am not sure whether these forms are valid forms of 

 kirbyellus or not. If lysholmi is valid, it was, in all proba- 

 bility, described from a melanic specimen. 



