WHEELER: ANTS OF THE GENUS FORMICA. A477 
than the head through the eyes. Base of epinotum with a median 
longitudinal impression, metanotum concave. Petiole very thick 
and blunt above, anterior and posterior surfaces both convex, border 
with a faint median notch. 
Head, thorax, legs, and antennae subopaque, finely shagreened; 
mandibles, clypeus, frontal area, vertex, and scutellum shining as are 
also the petiole and especially the gaster. 
Hairs and pubescence grayish, the former short and erect on the 
clypeus, thorax, gaster, and legs; the latter sparse and indistinct 
except on the antennae and legs. Eyes almost imperceptibly hairy. 
Black; mouthparts, legs, and genitalia fuscous. Wings like those 
of the female but of a slightly darker tint. 
Host (Temporary). Probably F. neogagates. 
Type LOCALITY.— Connecticut: Colebrook, 1,400 ft. (Wheeler). 
Massachusetts: Stony Brook Reservation, Chestnut Hill, near 
Boston (Wheeler). 
Illinois: Black Hawk Springs, near Rockford (Wheeler). 
The female nepticula resembles the female nevadensis, but differs 
in having much fewer erect hairs on the antennal scapes and body and, 
owing to the nearly complete absence of grayish pubescence, a more 
shining head and thorax. Moreover, the head, thorax, and appendages 
are decidedly darker and less red than in nevadensis. The worker 
nepticula may be readily confounded with that of F. truncicola ob- 
scuriventris owing to both forms having the same color and the same 
luster of the gaster, but nepticula is of average smaller size, has much 
sparser, coarser, and more obtuse hairs, the border of the clypeus is 
more projecting, and the epinotum is much lower and rounder. 
F. nepticula is, in my experience, a rare ant. It nests in open woods 
under stones, the edges of which it banks with vegetable detritus. 
The colonies are rather small. The males and diminutive females 
make their appearance early in July. 
63. F. DIFFICILIS Emery. 
F. pallidefulua Mayr (nec Latreille), Verh. Zool. bot. ver. Wien, 1866, 16, 
p. 889, 9. 
F. rufa subsp. difficilis Emery, Zool. jahrb. Syst., 1893, 7, p. 651, pl. 22, 
figs. 9,14,8 9 of. 
F. difficilis Wheeler, Bull. Amer. mus. nat. hist., 1904, 20, p. 348; Ibid., 1906, 
22, p. 63. 
Worker. Length: 3.5-5.5 mm. 
Head, excluding the mandibles, slightly longer than broad, slightly 
