506 bulletin: museum of comparative zoology. 



often confined to a spot on the pronotum and one on the mesonotum ;: 

 medium sized workers often have the pleurae more or less infuscated 

 and in the smallest workers the whole thorax may be dark brown. 

 Base of gaster and venter usually paler than the upper surface. Peti- 

 ole more compressed anteroposteriorly, with flatter anterior and pos- 

 terior surfaces and sharper border than in any of the preceding forms 

 of fusca. 



Female. Length 6-8 mm. 



Resembling the worker, Init the gaster even more shining. This 

 region is also more spherical and less elliptical than in the other forms 

 oi fusca. The head and thorax are subopac^ue, except the frontal area, 

 which is shining. Posterior border of the pronotum and the disc of 

 the mesonotum with a few large, scattered punctures. 



Reddish brown, posterior portion of head, upper surface of gaster, 

 posterior border of pronotum, the mesonotum, scutellum, and metano- 

 tum blackish or dark brown. The pleurae may also be clouded with 

 this color. Petiole and legs more yellowish brown. In some speci- 

 mens (from California) the thorax is pure reddish brown, with three 

 large spots on the mesonotum, the metanotum and posterior portion 

 of the scutellum black. Wings colorless, with pale brown veins and 

 darker stigma. 



Male. Length 6-7 mm. 



Head and thorax, including the frontal area, opaque; mesonotum 

 covered with coarse, scattered punctures. Epinotum, petiole, and 

 gaster shining. Erect hairs on thoracic dorsum, petiole, and base 

 of gaster rather abundant. Pubescence very sparse and rather long. 

 Black; gaster dark brown; genital appendages distinctly infuscated. 

 Legs yellow, middle portions of femora slightly infuscated. Antennae 

 black; only the tips of the mandibles brownish. Wings as in the 

 female. 



Type locality.— Colorado: Ward, 9,000 ft. (T. D. A. Cockerell). 



Colorado: Arapahoe Peak, timberline. Long's Peak, 12,500 ft. 

 (T. D. A. Cockerell); Cripple Creek, 10,200 ft., Cheyenne Mountain, 

 8,000 ft. (Wheeler); Canyon City (P. J. Schnn'tt). 



New Mexico: N. E. Truches Peak, 12,000-13,000 ft., above timber- 

 line (Mrs. W. P. Cockerell and Miss Ada Springer); Harvey's Ranch, 

 Las Vegas Range, 9,600 ft. (Miss Ruth Reynolds) ; Top of Las Vegas- 

 Range, 11,000 ft. (T. D. A. Cockerell). 



Arizona: Coconino Forest, Grand Canyon, 7,000 ft. (W' heeler). 



California: Alta Peak, Sequoia National Park, 9,500-11,000 ft.,. 

 Blue Lake, Humboldt Co. (J. C. Bradley). 



Oregon: (Amer. Mus. Nat. Hist. Coll.). 



Washington: Three Brothers, Olympic Range (J. C. Bradley). 



