wheeler: ants of the genus formica. 479 



New Jersey: Lakehurst, Halifax (Wheeler); Brown's Mills Junc- 

 tion (W. T. Davis). 



New York: Bronxville (Wheeler). 



This ant, originally described as a form of rufa, occurs sporadically 

 in open mountainous woods from New York state to North Carolina 

 and probably somewhat further south along the AUeghanies. It 

 nests under stones, which it banks with vegetable detritus. The 

 colonies are often moderately large. 



64. F. DiFFiciLis var. coxsocians Wheeler. 



F. difficilis var. consocians Wheeler, Bull. Amer. mu.s. nat. hist., 1904, 20, 

 p.371, g 9 cf; Ibid., 1906, 22, p. 50. 



Worker. Length 3.5-5.5 mm. 



Closely resembling the typical form, but the erect hairs more abun- 

 dant and slightly longer, especially on the front, gula, and thorax. 

 There are also numerous hairs on the posterolateral corners of the head, 

 which are nearly always lacking in the typical difficilis. The petiolar 

 border is somewhat sharper and the frontal area is smoother and more 

 shining. 



Female. Length 4-5.5 mm. 



Differing from the female of the typical consocians in having the 

 pubescence and pilosity more abundant. The former is rather dense 

 so that the whole body except the anterior portion of the head appears 

 much less shining. The tibiae have long, scattered, oblique or sub- 

 erect hairs which are lacking in the typical difficilis. Wings grayish 

 hyaline, darker at the base. 



Male. Length 5.5-6.5 mm. 



Mandibles broad, usually edentate, but occasionally with minute 

 teeth at the base. Clypeus sharply carinate. Petiole thick, trans- 

 verse, its anterior surface angularly convex, its posterior surface more 

 flattened, its border obtuse, seen from behind broadly rounded and 

 entire. 



Body subopaque, head and gaster somewhat more shining. Man- 

 dibles coarsely punctate. Frontal area smooth and shining. 



Hairs yellowish, erect, rather abundant on the head, mesonotum 

 and petiole, sparse on the pleurae and upper surface of the gaster. 

 Tibiae with a few small oblique hairs. Eyes hairless. Pubescence 

 rather long and conspicuous on the thorax and gaster, shorter and 

 sparser on the head, dense and very fine on the legs. 



Head and thorax black; mandibles, antennae, petiole, and gaster 

 dark brown; legs and genitalia light yellow; fore femora sometimes 

 slightly infuscated. Wings grayish hyaline, distinctly infuscated 

 towards their bases ; veins and stigma brown. 



