562 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
142. F. MICROGYNA RASILIS var. PULLULA, var. nov. 
Worker. Length 3.5-6 mm. 
Differing from the typical rasilis in color, the red portions of the 
body being decidedly darker and more brownish red. The petiole 
is more compressed anteroposteriorly, with a sharper border, which is 
more produced upward in the form of a blunt point. The erect, 
blunt hairs on the upper surface of the head and thorax, especially 
on the latter, are shorter and even less numerous. In many specimens 
they are altogether lacking on the front and thorax. 
FremaLe. Length 5 mm. 
Differing from the female of rasilis in color and in the shape of the 
petiole. Head, thorax, and gaster dark brown or blackish; mandibles, 
clypeus, cheeks, and gula dark red; antennal scapes, propleurae, epi- 
notum, petiole, and legs somewhat paler, dull red. Head and thorax 
opaque, gaster slightly glossy, with very short, rather sparse pubes- 
cence. Wings grayish hyaline; stigma light brown, veins paler. 
Petiole as in the worker, but its border even more produced and atten- 
uated in the middle. 
Described from numerous workers and three winged females taken 
from two colonies at Flathead Lake, Montana, by Prof. C. C. Adams. 
In the coloration of the worker and shape of the petiole this variety 
resembles F. adamsi Wheeler, but is larger and the head and thorax 
are at most very faintly and diffusely clouded with fuscous and not 
spotted. 
143. FoRMICA MICROGYNA RASILIS var. NAHUA, var. nov. 
WorkeER. Length 4-6 mm. 
Differing from the worker of the typical rasilis in having the petiole 
narrower and its margin distinctly blunter, the erect, obtuse hairs on 
the head and thorax somewhat more numerous and also present on 
the border of the petiole and on the gula; the sculpture is somewhat 
sharper, so that the sides of the head are opaque like the remaining 
surface, and the color of the gaster is darker and more blackish. 
Even the largest workers have no infuscation on the ocellar triangle 
and very rarely have faint blotches on the pro- and mesonotum. 
The tibiae are naked as in the typical rasilis. 
Femae. Length 6 mm. 
Differing from the female of rasilis in being a little larger and more 
robust, in having more numerous erect, obtuse hairs on the head, 
thorax, and gaster, a blunter petiolar border and in color, which is 
