WHEELER: ANTS OF THE GENUS FORMICA. 409 
9. F. SANGUINEA SUBNUDA Emery. 
F. sanguinea rubicunda var. subnuda Emery, Zool. jahrb., Syst., 1895, 8, p. 
335; 8. 
F.. sanguinea subsp. subnuda Wheeler, Ants, 1910, p. 458, 570. 
WorkKeER. Length 5-8 mm. 
Head like that of the typical rubicunda but the clypeal emargina- 
tion is much shallower, often reduced to a feeble sinuosity. Epino- 
tum often more rounded and less angular in profile, especially in 
smaller workers, in larger ones, however, often as angular as in the 
typical rubicunda and aserva. Petiole rather broad, with sharp, entire, 
or very feebly sinuate superior border. 
Surface like that of rubicunda, the gaster usually slightly more 
opaque. 
Hairs grayish or yellowish, much less abundant than in the typical 
rubicunda and its var. sublucida, nearly always completely absent on 
the thoracic dorsum, gula, and petiolar border. There are only a 
few hairs on the upper surface of the head and those on the gaster are 
decidedly short and sparse. Pubescence on gaster dense but finer 
than on the typical rubicunda, concealing the surface; on the thorax 
and head very sparse or absent and often not perceptible under an 
ordinary magnification. 
Color variable, but usually a light, rich red like that of the typical 
rubicunda, in some cases, however, more brownish; gaster black, as a 
rule, but occasionally with each segment brownish or reddish towards 
its base. 
FEMALE. Length 8-9 mm. 
Closely resembling the worker in sculpture and pilosity, but the 
red portions of the body somewhat browner. Dark spots on the 
mesonotum faint or wanting. Wings colored as in the typical rubi- 
cunda, if anything somewhat more deeply. Clypeal border more 
deeply notched than in the worker. 
Mate. Length 8-9 mm. 
Differing from the males of the preceding forms of sanguinea in 
having the anterior border of the clypeus entire and evenly rounded; 
its surface is convex and carinate. Mandibles dentate. Petiole 
somewhat more compressed anteroposteriorly and with a sharper 
border than in rubicunda. There are no erect hairs on the head and 
thorax and the hairs on the gaster are short and sparse. Pubescence 
short and dilute so that the surface of the head, thorax, and gaster is 
more shining than in the typical rubicunda. 
Hosts (Staves). F. fusca vars. subsericea, argentea, subaenescens, 
and gelida; large colonies often without slaves. 
Tyrer Locatity.— British Columbia: Yale, (Dieck). 
British Columbia: Vancouver I.; Field, Carbonate, 2,800 ft., Lake 
