458 bulletin: museum of compakative zoology. 



South Dakota: Harding County (S. S. Visher). 



The worker differs from those of ciliaia, comata, and orcas in the ab- 

 sence of hairs on the head, thorax, and petiole, and the female has 

 much fewer hairs and these are confined to the clypeus and gaster. 

 The hairs are very easily rubbed off in both workers and females, 

 but the long series of the former and the callows of the latter show that 

 they cannot be more abundant than described above. The colony 

 from which the type specimens were taken was very populous. Its 

 nest resembled very closely those of ciliata, comata, and oreas which 

 I have examined in Colorado. It was under several contiguous stones, 

 banked with vegetable detritus and in the immediate neighborhood 

 of flourishing colonies of F. ciliata and rufa aggcrans. 



47. F. OREAS Wheeler. 



F. oreas Wheeler, Bull. Amer. mus. nat. hist., 1903, 19, p. 643, S 9 cf • 



Worker. Length 4.5-7 mm. 



Resembling the workers of F. ciliata, comata, and criniventris. 

 Mandibles 8-toothed. Head, excluding the mandibles, as broad as 

 long, slightly narrower in front than behind, with feebly concave 

 posterior border, rather broadly rounded posterior corners, and convex 

 sides. Clypeus carinate its entire length, with broadly rounded, not 

 produced anterior border. Antennae rather slender, funicular joints 

 1-3 longer and more slender than the penultimate joints. Frontal 

 carinae rather strongly diverging. Palpi short. Thorax with convex 

 pro- and mesonotum and deep mesoepinotal constriction. Epinotum 

 with the base horizontal and slightly convex, distinctly longer than the 

 rapidly sloping and distinctly concave declivity with which it forms 

 an obtuse angle. Petiole broad, compressed anteroposteriorly with a 

 sharp superior border, which is either bluntly pointed or slightly trun- 

 cated in the middle. 



Body subopaque, very finely shagreened, anterior portion of head 

 smooth and shining, mandibles and clypeus longitudinally striated, 

 shining; frontal area glabrous. 



Hairs silvery white or pale yellow, short, abundant, erect, covering 

 both the dorsal and gular surfaces of the head, the thorax, border of 

 petiole, and gaster. Hairs on the ocellar region conspicuously long. 

 Scapes and legs covered with shorter, suberect hairs. Hairs on the 

 gaster pointed and more delicate than in the three preceding species, 

 long on the venter and terminal segments. Eyes hairy. Pubescence 

 yellowish, sparse on the head, somewhat more abundant on the thorax 

 and sufficiently dense on the gaster to conceal the surface and give it a 

 grayish tinge. 



