528 WHEELER. 



and females from Creede Co., Colo., 8844 ft. (S. J. Hunter) also 

 belong to this subspecies. It is evidently quite distinct from the 

 other forms o1 flavus. It resembles the subspecies myops in preferring 

 hot, stone-covered slopes to moist, shady places as a habitat. 



85. Lasius {Formicina) umhratus Nyl. subsp. subumbratus Viereck. 

 New Mexico: Beulah, 8000 ft., type-locality (T. D. A. Cockerel!). 

 Colorado: Cheyenne Canyon near Colorado Springs, Williams 



Canyon near Manitou, and Boulder (Wheeler); Canyon City (P. J. 

 Schmitt). 



Utah: Little Willow Canyon, Salt Lake County (R. V. Chamberlin). 



Arizona: Wilhams, 7000 ft. (Wheeler). 



California: Angora Peak, near Lake Tahoe, 8000 ft. (Wheeler). 



Ontario: Ottawa (Wheeler). 



Quebec: Hull (Wheeler). 



Maine: Reed's Island, Penobscot Bay (A. C. Burrill). 



Nova Scotia: Digby (J. Russell); Bedford (W. Reiff). 



The list of localities shows that this form has a very wide range. 

 It is the most boreal of our forms of umhratus and is confined to the 

 Canadian Zone. 



86. Lasius (Formicina) umhratus subsp. mixtus Nyl. var. aphidicola 

 Walsh. 



This form, so abundant in many localities east of the Rocky Mts., 

 is very rare further west. During the summers of 1903 and 1906 I 

 found a few colonies near Florissant and Colorado Springs, Colorado. 

 They nest by preference in moderately moist, shady places. This 

 probably accounts for their almost complete absence from the arid 

 portions of the country. 



87. Lasius (Formicina) umhratus subsp. vcstitus W^heeler. 

 Known only from a female specimen taken by Prof. J. M. Aldrich 



at Moscow, Idaho. 



88. Lasius (Formicina) humilis sp. nov. 

 Worker. Length 1.5-1.7 mm. 



Head as broad as long, a little narrower in front than behind, with 

 broadly and feebly excavated posterior border and feebly and regularly 

 convex sides. Eyes very small, somewhat larger than in the typical 

 brevicornis, flat, with only about six ommatidia in their greatest diam- 

 eter. Antennae slender; scapes extending beyond the posterior 



