166 HYMENOPTERA. 



siderable amount of yellowish ferruginous pile, and the very tip usu- 

 ally extending distinctly beyond the tip of the last dorsal segment. 



Witif^s — Considerably stained with brown, the fore pair usually dark- 

 est in the region beyond the veins. 



Legs — Mostly dark ; the hind metatarsi fully three times as long as 

 their greatest breadth, their hind margins slightly arcuate. 



Dimensions — Length, 12 mm. to 16 mm. ; spread of wings 29 mm. 

 to 38 mm. ; width of abdomen at second segment, 6^ mm. to 9 mm. 



Habitat. — I have records of this species as follows ; Maine 

 (Orono), Massachusetts (Amherst— a single 9 ), New Hamp- 

 shire (Webster, Durham, Crawfords. Mt. Washington and 

 Conway), New York (Ithaca), Washington (Mt. Ranier), 

 British Columbia (Kaslo and Metlakatla) and Alaska (Nush- 

 agak and Sitka). It belongs mainly to the Boreal region, 

 but it runs over into the Transition Zone somewhat. Exten- 

 sive collecting will probably extend the range of habitat 

 given above considerably. In the West, it will probably be 

 found to range south into Colorado and Northern California. 

 In the East, it seems to be about as common as ashtoni. It 

 is surely present in Vermont. 



I am strongly of the opinion that fernaldce is the female of 

 tricolor. I have evidence to support this opinion as follows : 



1. Both fernaldcB and tricolor, as shown by their structure, 

 are without any very close known allies in the New World 

 and they are the only species which appear to stand thus 

 isolated. 



2. They have about the same range of habitat, though tri- 

 color has been taken in Colorado while fernaldce has not. 



3. The fernaldcE females alone ever have a touch of ferru- 

 ginous pile on the sides of the fifth dorsal abdominal seg- 

 ment to correspond with the pile of the same color on the 

 apex of the abdomen of the tricolor males. 



4. The closest allies of {ernaldce known to me, are the 

 females of the European species, P. qiiadricolor and P. glo- 

 bosus, and the males of those same two species are the closest 

 allies of tricolor, as shown by the descriptions, figures of 

 genitalia, etc., of Schmiedeknecht (Apid. Europ. 1882, pp. 

 406 and 409 and Tab. 14, figs. 4, 5 and 6). There are speci- 

 mens of both sexes of both guadricolor and globosiis, labeled 



