wheeler: ants of the genus formica. 423 



Hairs and pubescence grayish, both very abundant, covering the 

 head, thorax, and gaster; the hairs erect and rather short, the pubes- 

 cence very long; eyes, scapes, and legs hairless. 



Black; genitalia heavily infuscated; mandibles brown with yellow- 

 ish tips; legs yellow, terminal tarsal joint of each foot black; wings 

 uniformly gray, or smoky, with brown veins and black stigma. 



Type locality. — Colorado: Canyon City (P. J. Schmitt). 



Colorado: Cotopaxi (P. J. Schmitt). 



New Mexico: Paraje, Las Valles (T. D. A. Cockerell); Alamogordo 

 (G. V. Krockow). 



Arizona: Tucson, Benson (Wheeler); Tempe (T. D. A. Cockerell). 



Nevada: Las Vegas (J. C. Bradley). 



Texas: San Esteban near Marfa, Langtry, Ft. Davis (Wheeler); 

 Eagle Pass (J. D. Mitchell). 



Mexico: Coahuila (A. F. Rangel). 



This ant is certainh' not a form of snbpolita, nor does it belong with 

 fusca, as I formerly supposed. It is closely related to the preceding 

 species (F. manni), but differs in the greater size of the worker and 

 especially of the female, the more robust body and antennae, more 

 convex mesonotum, more abundant and longer pilosity and pubescence. 

 F. manni might, perhaps, be regarded as a subspecies of pcrpUosa. 

 The notch in the clypeus of the worker of the latter species is shallower 

 and less constant, especially in small individuals than in manni. 



Since the original account of this species was published ten years ago, 

 I have had several opportunities of studying it in xArizona and Western 

 Texas. It is preeminently a species peculiar to u-rigated lands and 

 river l)ottoms in the deserts of the southwest. There it nests in 

 rather populous colonies about the roots of bushes or trees, often form- 

 ing obscure craters or low mound nests, not unlike the nests of F. 

 subsericea in the Eastern States. I have never found it nesting under 

 stones. It is a very active and aggressive ant, and, as Herrera has 

 shown, is of some little economic value as a boll-weevil exterminator. 

 There is not the slightest indication that it is either a temporary social 

 parasite or a slave-holder. 



19. F. BRADLEYI, Sp. HOV. 



Worker. Length 3.5-5 mm. 



Head, excluding the mandibles, a little longer than broad, a little 

 narrower in front than behind, with straight sides and straight or 

 feebly convex posterior border. Eyes rather large. Clj'peus convex, 

 carinate, its anterior border not produced, broadly rounded, with a 

 very shallow, broad excision in the middle. Frontal carinae subparal- 



