WHEELER: ANTS OF THE GENUS FORMICA. 461 
49. IK. FEROCULA, sp. nov. 
p 
Worker. Length 3.5-6 mm. 
Head, excluding the mandibles, as broad as long, broader behind 
than in front, with feebly excised posterior border and very slightly 
convex sides. Mandibles 8-toothed. Clypeus convex, carinate its 
entire length, with broadly rounded anterior border, but slightly or 
not at all produced in the middle. Frontal area triangular, as long 
as broad. Frontal carinae short, diverging. Antennae slender, four 
basal funicular joints longer and more slender than the penultimate 
joints. Palpi short. Pro- and mesonotum not very convex, meso- 
épinotal constriction not very deep, epinotum with subequal base and 
declivity, the former feebly convex, the latter distinctly concave. 
Petiole narrow and very low, its anterior surface very convex, its pos- 
terior surface flattened, its border very blunt and when seen from 
behind, evenly rounded and entire, not produced upward in the 
middle. Legs rather long. 
Opaque, finely shagreened; mandibles shining, rather superficially 
striatopunctate; frontal area smooth and shining, clypeus also more 
shining than the posterior part of the head. 
Hairs and pubescence golden yellow; the former abundant on 
the clypeus and mandibles, absent on the remaining portions of the 
head; dense and erect on the pronotum, epinotum, and petiole, absent 
on the mesonotum, except at the posterior border. On the gaster the 
erect hairs are short, obtuse, and rather abundant. Eyes hairless. 
Pubescence long and rather dense on the head and thorax, scarcely 
denser on the gaster and not concealing the ground color. Pubescence 
on the legs long and somewhat oblique on the flexor surfaces of the 
tibiae. 
Bright yellowish red; mandibles, antennal funiculi towards their 
tips, and the legs in some specimens, darker. Gaster dark brown, 
with the anal region and a spot at the base of the first segment red. 
Very small workers have the upper surface of the head, thorax, and 
petiole infuscated and the legs darker. 
Described from sixteen workers taken from a single colony at 
Rockford, Illinois. This and several other colonies of the same species 
were found nesting in dry, open fields in crater nests 3-4 inches in 
diameter about the roots of Hrigeron canadense and other weeds. The 
species is evidently allied to F. comata, criniventris, ciliata, and oreas, 
but differs from all of these forms in the peculiar shape of the petiole 
and the arrangement of the hairs. The female is probably of a pecu- 
har aberrant type, like the females of the forms just mentioned. 
