538 WHEELER. 



110. Formica truncicola subsp. integroides var. tahoensis var. nov. 



Worker. Length 4-6 mm. 



Resembling the subsp. integroides but differing in its decidedly- 

 smaller average size, in the shape of the head, larger eyes, pilosity and 

 coloration. The head is narrower in front with much less convex, 

 anteriorly converging cheeks and straight posterior border, so that 

 it is distinctly trapezoidal with less rounded posterior corners. Sur- 

 face of body opaque, mandibles lustrous, frontal area shining. The 

 erect hairs are extremely sparse on the head and thorax, usually 

 restricted to a few scattered hairs on the clypeus and upper surface 

 of the head. Pubescence grayish, abundant, especially on the gaster. 

 Gaster black, with red anal region. In large workers the head, 

 thorax, petiole and appendages are red, with the apical half of the 

 antennal funiculus infuscated, but often even the largest workers 

 have the ocellar triangle, the upper portion of the petiole and a spot 

 on the pro- and mesonotum blackish and the coxae, femora and tibiae 

 dark red or fuscous. The infuscation of the red portions of the body 

 may be even more extensive in small individuals. 



Female. Length 8.5-9.5 mm. 



Differing from the female integroides in lacking erect hairs on the 

 upper surface of the thorax and pedicel, the gula and posterior por- 

 tions of the head. The head, thorax, petiole and appendages are uni- 

 formly red in some specimens, in others the metanotum and posterior 

 portion of the scutellum are black and there may be three elongate 

 black blotches on the mesonotum or only a single anteromedian blotch. 

 Wings grayish hyaline, with their basal halves distinctly infuscated; 

 veins and stigma brown. 



Described from numerous workers and four deJilated females taken 

 from several colonies near Lake Tahoe, Cala. (Tallac, Glen Alpine 

 Springs, Fallen Leaf Lake, Angora Peak), and a single female taken 

 by Prof. C. F. Baker in Ormsby County, Nevada. In the almost 

 complete absence of erect hairs on the head, thorax and petiole, this 

 variety resembles the var. haemorrhoidalis, but the worker averages 

 distinctly smaller, has a differently shaped head and the smaller and 

 even some of the larger workers are more or less spotted with black. 

 It is less hair}^ than the typical integroides and the gaster is darker. 

 Like the other forms of the subspecies it forms large colonies in stumps 

 and logs which it banks with much vegetable detritus. 



111. Formica truncicola subsp. integroides var. propinqua var. nov. 

 Worker. Very similar to the preceding both in size and coloration, 



