MOUNTAIN ANTS OF NORTH AMERICA. 553 



tana, and three workers taken by Dr. S. J. Hunter at Beaver Creek, 

 6300 ft. in the same state also belong to this species, though the thorax 

 in the former is more reddish and the cheeks and clypeus are deep red. 

 Some workers from a single colony at Field seem to represent a hybrid 

 form between hewitti and the typical /u5ca. Only an occasional worker 

 in this series has one or two erect hairs on the gula and the color, 

 pubescence and sculpture is more like certain forms of fusca that are 

 intermediate between the type and the var. subsericca. Like the fol- 

 lowing species and F. sibylla, hewitti is a puzzling form, since, owing 

 to its peculiar pilosity, it cannot be assigned either to fusca or to 

 cinerea. 



164. Formica stihcyanea Wheeler. 



This species is known only from the state of Hidalgo, Mexico, where 

 it was taken in several localities at elevations of about 9000 ft. by Dr. 

 W. M. Mami. The worker and female are readily distinguished by 

 the very opaque, blue-black surface of the body, entirely black legs, 

 antennae and mandibles and the sparse, erect hairs on the gula. 



165. Formica subpolita Mayr. 

 California: Mt. Tamalpais (Wheeler). 

 Oregon: Ashland (W. Taverner). 



The typical form of this species is known only from the coast of 

 California, Oregon, Washington and British Columbia. I failed to 

 find it in the Yosemite or about Lake Tahoe though it ascends to an 

 elevation of at least 6400 ft. in the Coast Range in Southern California. 



166. Formica subpolita var. camponoticeps Wheeler. 

 California: Yosemite Village, 4000 ft. (Wheeler). 



This variety has been recorded from several localities in Washing- 

 ton. The Californian specimens agree in all particulars with the 

 tj'-pes. Each of the numerous colonies which I found nesting under 

 stones on the dry slope of the canyon wall near Yosemite Village 

 contained workers of very different sizes. These colonies were all 

 much less populous than those of the typical subpolita, which prefers 

 a moister environment. In several of the nests I took mature larvae 

 of a Coccinellid {Brachyacantha sp.) resembling those which occur 

 in the nests of Acanthomyojjs. 



167. Formica subpolita var. ficticia Wheeler. 



Montana: Helena and Elkhorn Mts. (W. M. Mann); Flathead 

 Lake (C. C. Adams); Missoula; Gallatin Co., 6500 ft. 

 Colorado: Boulder and Buena Vista (Wheeler). 



