MOUNTAIN ANTS OF NORTH AMERICA. 535 



106. Formica hradleyi Wheeler. 



Colorado: San Miguel, 12,000 ft. and Bullion Peak, Park Co. 12,000 

 ft. (E. J. Oslar). 



Montana: Missoula. 



Pre^'iously known only from workers taken at Georgetown, Colo, 

 and Medicine Hat, Alberta. It is evidently an exclusively alpine 

 species. The two specimens from Missoula are females. They 

 measure nearly 7 mm. and are colored like the worker, red throughout, 

 except the posterior borders of the gastric segments which are fuscous. 

 The surface of the body is subopaque. The petiole is cuneate in pro- 

 file, broad below, with flat anterior and posterior and rather sharp, 

 emarginate superior border. The notch in the middle of the anterior 

 clypeal border is very distinct. The wings are grayish hyaline, with 

 brown stigma and yellowish brown veins. 



107. Formica rufa L. subsp. obscuripes Forel. 

 British Columbia: Glacier (Wheeler). 

 Alberta: Banff (Wheeler). 



Manitoba: Treesbank (C. G. Hewitt). 



Montana: Beaver Creek (S. J. Hunter). 



Wyoming: Cheyenne (Fanny T. Hartman): Rock River (S. J. 

 Hunter). 



Colorado: Creede, 8844 ft. (S. J. Hunter); Tolland (W. W. Rob- 

 bins); Jefferson (A. K. Fisher). 



California: Tallac, Lake Tahoe (Wheeler). 



Washington: The eastern part of the state (W. M. Mann). 



The attempts in my "Revision" to dissipate the confusion in regard 

 to our American forms of rufa, prove to have been unsuccessful and 

 I must here make another attempt. I believed that I could recognize 

 four forms of this species, the subsp. obscuripes Forel, the subsp. 

 aggerans (a new name for Emery's rubiginosa {nom. praeocc.)), the var. 

 melanotica Emery and a var. whymperi described by Forel as belong- 

 ing to obscuripes but at the time unknown to me. I have since found 

 this variety in British Columbia and am able to state that it does not 

 belong to rufa or obscuripes but is a distinct species of the microgyria 

 group and is very close to the form I described as F. adamsi {vide 

 infra). The var. mekmotica is a very definite color variety of obscu- 

 ripes and need not be discussed. Doubt remains then only in regard 

 to the typical obscuripes and aggerans. Although I studied much 

 material from a number of localities I was unable to distinguish these 

 forms satisfactorily for the reason that both were inadequately 



