MOUNTAIN ANTS OF NORTH AMERICA. 547 



Washington: Mt. Renier (J. C. Bradley). 



California: Lake Tahoe, 6000-7000 ft. and Glacier Point, Yosemite 

 (Wheeler). 



Previously cited from various localities in South Dakota, Utah, 

 Montana, Idaho, Oregon, Washington, British Columbia and Alberta. 



I found many colonies in the localities above recorded and secured 

 all three phases so that I am able to improve on the description given 

 in my "Revision." 



The workers vary greatly in size in each colony, from 3.5-5.5 mm. 

 The largest have the head, including the clypeus, palpi and antennae 

 black, with the scapes, cheeks and mandibles deep red or castaneous, 

 the gaster black and shining, with very short grayish pubescence, the 

 thorax, petiole and legs opaque and immaculate red. The medium- 

 sized workers have a black spot on the pro- and one on the mesonotum ; 

 the smallest workers have the whole thorax, petiole and legs dark 

 brown. The petiole is broad, much compressed anteroposteriorly, 

 with broadly rounded, rather sharp border. 



The female measures 7-8 mm. and is colored like the worker, except 

 that the sides of the pronotum and the pleurae are clouded with fuscous 

 and the metanotum and posterior border of the scutellum and three 

 large, elongate blotches on the mesonotum are black. The thorax is 

 as shining as the head. The petiole is very broad, very much com- 

 pressed anteroposteriorly, with flat anterior and posterior surfaces and 

 sharp, broadly rounded superior border. Wings clear grayish hyaline 

 with pale brown veins and dark brown stigma. 



The male measures 7-7.5 mm. and is larger than the male of gelida. 

 It differs also in having the legs rich yellow, with the base of the femora 

 slightly infuscated and the gaster more shining, with much shorter 

 pubescence and much fewer erect hairs on the head and thorax. 



This ant nests by preference in old logs in hot sunny places, but 

 both at Lake Tahoe and in British Columbia I often found it nesting 

 under stones. Several pseudogynes were taken in both localities. 

 They are small (3-4 mm.) and have the dorsal surface of the pro- 

 and mesonotum and the scutellum black. 



The specimens cited in my "Revision" as belonging to gelida from 

 Blue Lake, Humboldt Co., and Alta Peak, Cala. and from Kassiloff 

 Lake, Kenai Peninsula, Alaska, have the color of the var. neorufibarhis 

 but the pubescence of gelida. They may be regarded as representing 

 a form intermediate between the two varieties. Owing to its con- 

 stancy and the pronounced variation in size of the workers of the same 

 colony, neorufibarhis should, perhaps, rank as a subspecies. 



