474 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
latter flattened or slightly concave; the two surfaces passing into each 
other through a distinct but rounded angle. Petiole narrow, in pro- 
file compressed anteroposteriorly, with convex anterior and flattened 
posterior surface and sharp superior border, which when seen from 
behind is rounded and usually but slightly produced upward in the 
middle. 
Opaque throughout, except the bases of the mandibles, the frontal 
area, and sides of the clypeus, which are shining. Mandibles finely 
and densely striated. Surface of body densely and indistinctly sha- 
greened. 
Hairs and pubescence pale yellow; the latter covering the whole 
body and appendages, not conspicuous except on the gaster, but even 
on this region not sufficiently dense to conceal the surface sculpture. 
Hairs short, sparse and obtuse, in several rows on the gastric segments; 
on the thorax confined to the upper portions of the pro- and mesonotum, 
on the head to the clypeus, front, and vertex. The hairs on the mandi- 
bles are appressed and pointed, on the palpi short but numerous and 
conspicuous. Legs and antennae naked, the former only with a series 
of pointed bristles on the flexor surfaces of the tibiae and tarsi and a few 
blunt hairs on the anterior surfaces of the fore coxae. 
Sordid brownish red, the smaller specimens somewhat more yellow- 
ish red. Gaster dark brown, except a large spot at the base of the 
first segment and the anal region, which are reddish yellow. A large 
spot on the pronotum, one on the mesonotum, much of the postero- 
dorsal portion of the head, the distal halves of the antennal funiculi 
and in many specimens also the coxae and femora, dark brown or 
blackish. These dark markings are present in the largest as well as 
in the smallest workers. 
Host (Temporary). Probably F. fusca. 
TyprE LocaLity.— Michigan: Isle Royale (H. A. Gleason). 
In coloration, this ant resembles very closely small specimens of 
the European F. rufa pratensis, and can be distinguished from all the 
preceding forms of the microgyna group by the extensive infuscation 
of the upper surface of the head. Mr. Gleason describes the nests 
on Isle Royale as “one of the most conspicuous features of the drier 
tamarack swamps. They are rounded-conical in shape, 3-6 dem. high 
or even larger, with a diameter at the base about equalling the height. 
They are composed within of Sphagnum, but as would be expected 
with such material, without any definite system of galleries. The 
outer surface is thickly covered with leaves of Cassandra, probably to 
prevent loss of moisture by evaporation from the interior. They are 
frequently placed near or under a bush of the Cassandra, but the same 
covering is used if no Cassandra is near.” 
