wheeler: ants of the genus formica. 515 



Worker. Length 4-7.5 mm. 



Very closely related to F. fusca and scarcely differing in structural 

 characters. The epinotum is distinctly angular in profile; the 

 petiole rather broad, compressed anteroposteriorly, with broadly 

 rounded, entire, rather sharp superior border. Legs and antennae 

 long. 



Head, thorax, and gaster, including the frontal area, opaque, densely 

 shagreened, venter and legs feebly shining. 



Hairs yellow, very sparse, present on the upper surface of the head, 

 pronotum and gaster, and sometimes also on the petiole and other 

 parts of the thorax. Pubescence dense and rather long, concealing 

 the surface, but without a silkj' gloss. 



Pale red, posterodorsal portion of head and the gaster blackish 

 brown. Mandibles dark red; funiculi, except at the base, the coxae 

 and sometimes also the middle portions of the femora, infuscated. 

 Rarely in large workers the pro- and mesonotum are slightly infuscated. 

 In small workers the infuscation of the thorax may be more extensive. 



Female. Length 9-11 mm. 



Resembling the worker in sculpture, pubescence, and color, but the 

 posterior margin of the pronotum, the scutelhmi, metanotum, more 

 or less of the pleural region, and three elongate blotches on the mesono- 

 tum, dark brown. The venter is usually reddish. Wings grayish 

 hyaline, with pale brown veins and darker stigma. Hairs longer and 

 more abundant than in the worker, especially on the thoracic dorsum. 



Male. Length 9-10 mm. 



Very similar to the male of fusca and its varieties, but the thorax 

 and gaster are more robust. Mandibles pointed, edentate. Petiole 

 though thick and low, with a sharp, compressed and very broadly 

 and distinctly excised border. 



Body opaque, gaster scarcely shining. Frontal area opaque. 



Hairs very sparse, present on the head, thoracic dorsum, and venter, 

 but absent elsewhere. Pubescence grayish, short and dense. 



Black; legs and genitalia yellow; tarsi of the former and tips of 

 appendages of the latter infuscated ; tips of mandibles brown. Wings 

 uniformly gray as in the female. 



Widely distributed through Europe and Northern Asia and occur- 

 ring in Sardinia though absent from the smaller Mediterranean Is- 

 lands. It is a distinctly xerothermal form and in the Alps does not 

 reach such an elevation as the typical fusca. According to Ruzsky, 

 however, it occurs at an altitude of 3,000 m. in the Caucasus, and 

 according to Forel even higher in the Himalayas. 



Although this ant is so very close to fusca in its morphological struc- 

 ture, I have ne\'ertheless followed the majority' of authors in regarding 

 it as a species and not as a subspecies of fusca. P. Huber and Forel 



