WHEELER: ANTS OF THE GENUS FORMICA. 447 
Pilosity and pubescence yellowish, abundant, the former suberect, 
absent on the upper surface of the gaster, which is covered with rather 
long, appressed pubescence. Legs covered with short, suberect 
hairs. Eyes hairy. 
Head and thorax, including the frontal area, opaque; gaster some- 
what shining. 
Black; legs and genitalia yellow, coxae and bases of the femora 
dark brown. Wings infuscated as in the female. 
Host (Temporary). F. fusca var. subsericea. 
TYPE LOCALITY.— Connecticut: (Mayr). 
Massachusetts: Stony Brook Reservation, Blue Hills, near Boston, 
Ellisville (Wheeler); Wellesley (A. P. Morse). 
Maine: Sebascodegan Island, Casco Bay (Wheeler). 
New York: Saugerties (G. v. Krochow); Ithaca (Cornell Univ. 
Coll.). 
New Jersey (Mayr). 
District of Columbia: Washington (A. Forel). 
Virginia (Mayr). 
Indiana: Culver, Tippecanoe Lake (W. S. Blatchley). 
Ilinois: Rockford (Wheeler). 
Wisconsin: White Fish Bay, near Milwaukee (Wheeler). 
Colorado: Florissant (Wheeler); Flagstaff Mt., Boulder (T. D. 
A. Cockerell). 
British Columbia: Carbonate, Ravelstoke (J. C. Bradley); Golden 
(W. Wenman). 
Ontario: Toronto (R. J. Crew). 
This ant was originally described from Connecticut, but in a later 
paper (1886) Mayr cited it from several of the Atlantic States and also 
from Colorado, California, New Mexico, and Arizona. As it is very 
rare in Colorado, and as I have never received it from other Western 
States, I believe Mayr must have confounded it with specimens of 
F. rufa aggerans. This would be easy for large greasy specimens of 
aggerans are very similar to large workers of obscurwentris. In 
fresh specimens, however, the gaster of the latter has a very different 
appearance, being much as in melanotica, but it is readily distinguished 
from this form by the uniform deep red color of the head, thorax, 
petiole, and legs. \ 
F. obscuriventris nests under large stones in open woods, often 
banking the edges of the stones with vegetable débris. The colonies 
are much smaller than those of integra, and integroides and rarely 
extend over more than one nest. Many queens are retained in the 
