wheeler: ants of the genus formica. 443 



front. Tibiae with oblique and rather long pubescence on their 

 flexor surfaces. Pubescence gray, long, dense, and suberect on the 

 gula, upper surface of the head and thorax, appressed on the antennal 

 scapes and gaster. The latter region is slightly more lustrous than in 

 the worker. 



Head, thorax, and petiole sordid brownish yellow; mandibles, ocellar 

 region, posterior corners of head, posterior border of pronotum, 

 mesonotum, scutellum, metanotum, mesopleurae, legs, antennae, 

 and sometimes also the upper border of the petiole, brown; gaster 

 blackish brown, with slightly reddish anal region. Wings distinctly 

 inf uscated, scarcely paler towards their tips ; veins and stigma brown. 



Male. Length 7-8 mm. 



Mandibles edentate, clypeus convex, carinate, transversely im- 

 pressed behind; head rather broad; eyes large. Petiole low and thick 

 with rounded, entire superior border. 



Mandibles and frontal area shining; head and thorax opaque; gas- 

 ter, pleurae, legs, and genitalia lustrous. 



Hairs yellowish, very short, erect, and rather abundant on the head 

 and thorax, sparser and more appressed on the upper surface of the 

 gaster, absent on the legs. Pubescence grayish, moderately developed, 

 most distinct on the gaster. 



Black; even the tips of the mandibles not paler; genital sclerites 

 black or castaneous, with yellowish insertions. Wings infuscated 

 as in the female. 



Type locality. — Colorado: Colorado Springs. (Wheeler). 



Colorado : Colorado City, Malvern, Wild Horse, Manitou (Wheeler) ; 

 West Chff (P. J. Schmitt). 



This form is rather puzzling. It is perhaps a distinct species, but 

 I have preferred to regard it provisionally as a subspecies of truncicola. 

 The small, almost hairless and peculiarly colored females enable one 

 to recognize the species better than the workers, which at first sight 

 resemble those of F. iruncicola intcgroidcs vars. haeinorrhoidalis and 

 coloradcnsis. The new form differs from these varieties, however, in 

 pilosity and pubescence, and in the smaller average size of all three 

 phases. The males are peculiar in being almost entirely black, even 

 to the greater portion of the genital appendages. 



I found several colonies of this ant both in 1903 and 1906, each con- 

 taining many females and males. They were nesting in open places, 

 at altitudes of about 5,000-7,000 feet, under stones banked with 

 vegetable detritus. 



