wheeler: ants of the genus formica. 497 



ences between the form which I described as the var. cjlaciaUs from 

 Maine and the true Em-opean fusca. The wings of the males and 

 females in the American form are perhaps slightly darker, but the tint 

 is variable in European specimens. The sculpture, color, and pubes- 

 cence are identical in the two forms. The specimens from Newfound- 

 land, including in all probability those from St. Pierre and Miquelon, 

 Newfoundland, mentioned by Emery (Zool. jalirb. Syst., 1893, 7, p. 

 660), and the specimens from Nova Scotia and New Brunswick agree 

 very closely with the cotypes from JVIaine. The western forms are 

 often a little more like subsericea in pubescence and may be regarded 

 as transitional to that variety. Should it be possible on further study 

 to detect any satisfactory differences between American and Eurasian 

 specimens, the term glacialis would, of course, have to be reinstated. 



The colonies of the American fusca are often much larger than those 

 which I have seen in Europe. In both continents it nests under stones 

 or logs or in rude craters or small earthen mounds. The workers are 

 extremely timid. This timidity, which characterizes all the varieties 

 and subspecies of F. fusca, together with its extreme fecundity, has 

 made it an ideal host for a large number of the parasitic species of 

 Formica of the sanguinea, rufa, microgyna, and exsecta groups. 



81. F. FUSCA FUSCA var. glebaria Nylander. 



F. glebaria Nylander, Acta. Soc. Fennica, 1846, 2, p. 917, ^ 9 , taf. 18, 

 fig. 23; Forster, Hymen, stud., 1850, 1, p. 31, y 9 cf . 



F. fusca var. glebaria Emery, Deutsch. ent. zeitschr., 1909, p. 196, S 9 ; 

 Karavvajew, Rev. Russe ent., 1909, p. 268. 



F. fusca subsp. glebaria Emery, Deutsch. ent. zeitschr., 1912, p. 672. 



Worker. Length 4-6.5 mm. 



Differing from the typical fusca in color and pilosity. The body is 

 deep brown or at any rate not deep black, and the pubescence is longer 

 and more abundant, especially on the gaster, so that the body is dis- 

 tinctly silky. The front of the head, the sutures of the thorax, the 

 scapes, and articulations of the legs are pale and more yellowish or 

 reddish. 



Female. Length: 7-9 mm. 



Resembling the worker in color and pilosity. The gaster is not 

 smooth and shining as in the typical fusca but subopaque and covered 

 with much denser pubescence and appearing glossy or silky. Wings 

 distinctly infuscated at their bases. 



Male. Length 8-9 mm. 



