June, 1909 ] Wheeler : North American Formtcid^, 85 



dense to conceal the surface sculpture. Hairs short, sparse and obtuse, in several 

 rows on the gastric segments ; on the thorax confined to the median portions of the 

 pro- and mesonotum, on the head to the clypeus, front and vertex. The hairs on the 

 mandibles are appressed and pointed, on the palpi short, but numerous and conspicu- 

 ous. Legs naked, except for a series of pointed bristles on the flexor surfaces of the 

 tibiae and tarsi and a few bltnt hairs on the anterior surfaces of the fore coxoe. 



Sordid brownish-red ; the smaller specimens somewhat more yellowish-red. 

 (iaster 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 meso- 

 notum, much of the posterior surface 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. 

 Teeth of mandibles black. 



Described from numerous specimens taken from a single colony 

 on Isle Royale, Michigan, and received from Dr. C. C. Adams. A 

 dpzen workers taken by myself on Pikes Peak, Colorado, near timber 

 line, at an altitude of 10,500 to 11,000 feet, differ from the Isle 

 Royale specimens only in having the frontal area smooth and shining, 

 the middle of the petiolar border produced upward as a distinct, blunt 

 point, and in the less extensive infuscation of the head, pro- and meso- 

 notum. These specimens may be regarded as representing a distinct 

 variety, which may be called alpina var. nov. Both this and the 

 typical adamsi may be distinguished from our other North American 

 Formicce of the rufa group by their small size, opaque surface and 

 peculiar coloration and pilosity. The following collector's note ac- 

 companying the Isle Royale specimens adds some ethological charac- 

 ters which are not observed in any of the other small forms of the rufa 

 group known to me : " The nests of this ant are one of the most con- 

 spicuous features of the drier tamarack swamps. They are rounded- 

 conical in shape, 3-6 dcm. high or even larger and 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 evapora- 

 tion from the interior. They are frequently placed under or near a 

 bush of Cassandra, but the same covering is used even if no Cassandra 

 is near." (H. A. Gleason.) 



8. Formica comata, new species. 



Worker. —Length 4.5-7 mm. 



Allied to F. ciliata Mayr. Head, excluding the mandibles, as broad as long, 

 broader behind than in front, with rounded posterior corners, feebly excavated pos- 

 terior margin and slightly convex sides. Eyes large. Mandibles 7 -toothed. Cly- 



