454 bulletin: museum of comparative zoology. 



scutellum, and the alar insertions black or infuscated. Wings uniformly 

 grayish hyaline ; veins and stigma more yellowish gray, the latter not 

 very conspicuous. 



Male. Length 6.5-8 mm. 



Mandi])les edentate, sharply pointed. Head very short, very broad 

 behind the eyes, very narrow in front, occipital border straight. 

 Clypeus strongly carinate. Maxillary palpi 5-jointed. Thorax 

 robust, broader than the head. Petiole thick, convex anteriorly, 

 more flattened posteriorly, border very blunt, evenly rounded and 

 entire both in profile and when seen from behind. 



Mandibles and upper surface of body slightly shining, remainder 

 of body, including the frontal area, opaque. 



Head, thorax, petiole, and base of gaster with short, rather dense 

 hair; pubescence grayish, moderately developed on these and the re- 

 maining portions of the body and appendages. Eyes distinctly hairy. 



Deep black even to the tips of the mandibles and appendages; geni- 

 talia yellowish, the separate sclerites tipped and bordered with black 

 and castaneous. Wings grayish hyaline, distinctly infuscated towards 

 their bases; veins dark brown, stigma black. 



Host (Temporary). Unknown; probably F.fusca var. argcntca. 



Type locality. — Colorado (Ma;yT). 



Colorado: Manitou, Ute Pass, Colorado City, Colorado Springs, 

 Malvern, Wild Horse (7,000-8,000 ft.) (Wheeler). 



Montana: Elkhorn (W. M. Mann). 



The aberrant type of female, with its remarkable pilosity so much 

 like the trichomes of many myrmecophilous beetles, suggests that 

 this ant must be a temporary parasite on some one of the Colorado 

 varieties of F. fusca, but up to the present time it has not been taken 

 in mixed colonies. Although the female may be distinguished at a 

 glance from the females of any of the known species of Formica, the 

 worker and male are not so easily recognized, since they closely re- 

 semble the various western forms of rufa and truncicola and the two 

 following species, comata and criniveiitris. The ground color and 

 pilosity of the gaster of the worker are, nevertheless, peculiar, the 

 erect hairs being very short and stubby, and more abundant than in 

 any of the foregoing species. 



45. F. COMATA W'heeler. 

 F. co??rato Wheeler, Journ. N. Y. ent. soc, 1909, 17, p. 85, y 9 &. 



Worker. Length 4.5-7 mm. 



Allied to F. ciliata Mayr. Head, excluding the mandibles, as broad 

 as long, broader behind than in front, with rounded posterior cor- 



