wheeler: ants of the genus formica. 563 



like that of the worker, with red and not brownish yellow, head, thorax, 

 petiole, legs, and antennae. The wings seem to be a little darker than 

 in the typical r as His. 



Male. Length 7 mm. 



Differing from the male of the typical rasilis only in having some- 

 what darker wings and a more opaque gaster. 



Described from several specimens of all three phases taken by 

 Mr. W. M. Mann at Guerrero Mill (9,000 ft.) and Velasco in Hidalgo, 

 Mexico, from populous colonies nesting under stones banked with 

 vegetable detritus. These colonies were very sporadic, but each con- 

 tained a large number of the small, winged females. Mr. Mann also 

 found these females (dealated) in two colonies of F. subcyanea, sp. 

 nov. {vide infra), thus proving that this is the temporary host of 

 nahua. 



144. Formica subcyanea, sp. nov. 



Worker. Length: 4-5.5 mm. 



Closely related to F. fusca. Head as broad as long, a little narrower 

 in front than behind, with feebly convex sides, rounded posterior 

 corners and straight posterior border. Eyes rather large. Clypeus 

 sharply carinate, with entire, slightly reflected but not produced an- 

 terior border. Antennae rather stout, the tips of the scapes a little 

 thicker and the terminal funicular joints a little shorter than in fusca. 

 Shape of thorax, petiole, and gaster as in fusca, the petiole having a 

 convex anterior and flat posterior surface and a broadly rounded, 

 entire upper border. 



Body, including the appendages, opaque, very coarsely shagreened 

 and in this respect resembling F. fusca var. japonica; gula and man- 

 dibles a little more shining, the latter coarsely striatopunctate. 



Hairs short, white, erect, a little more abundant on the head and 

 thorax than in fusca, obtuse on the gaster. Gula in the middle with a 

 very few erect hairs (1-4). Pubescence yellowish, extremely short, 

 moderately abundant on the head and gaster, less conspicuous on the 

 thorax and appendages. 



Deep black throughout, including the antennae, legs, palpi, and 

 mouthparts ; only the strigils of the fore tibiae and in some specimens 

 the bases of the scapes, reddish. Body in bright sunlight with dis- 

 tinct, deep metallic blue and bronze reflections. 



Female. Length 8-9 mm. 



Very much like the female of the typical F. fusca in size and shape. 

 Differing from the worker in having longer pubescence on the body and 

 in lacking the metallic blue reflections, though there is more or less 



