526 WHEELER. 



Manitou and Salida (Wheeler) ; Boulder (T. D. A. Cockerell); Canvon 

 City (P. J. Schmitt). 



Idaho: JuHetta (J. M. Aldrich); Troy (W. M. Mann). 



Utah: East Mill Creek, Salt Lake Co. (R. V. Chamberlin). 



New Mexico: Gallinas Canyon (T. D. A, Cockerell); Las Valles 

 (Mary Cooper). 



Arizona: Grand Canyon, 7000 ft. (Wheeler). 



California: Glacier Point, 8000 ft., Yosemite (Wheeler). 



Very common throughout the Middle and Eastern States as far south 

 as Georgia. That this variety should be attached to the European 

 subsp. alienus and not to the typical niger is evident from the absence 

 of erect hairs on the legs and antennal scapes and the sparse pilosity 

 of the body, and also from the fact that the female, especially in the 

 mountains of the western states, is indistinguishable in stature from 

 the female of the true alienus, measuring nearly 8 mm., with wings 

 9-10 mm. long, although the females of the typical eastern americanus 

 are often not more than 5-5.5 mm., with wings not exceeding 8 mm. 

 Both forms may occur in some of the middle-western states, e. g. in 

 Illinois and Wisconsin. The western form might be distinguished as 

 a variety, for which the name alicno-aincricanus would be appropriate. 

 The males, too, vary greatly in size and the differences of color among 

 the workers of different colonies are considerable. In the Eastern 

 States the workers of a form always found in dry sandy fields are very 

 pale, almost drab-colored, whereas in adjacent woodlands the workers 

 are always darker, varying from dark brown to black. Future study 

 on the basis of a large amount of material will probably lead to the 

 distinction of a number of forms of L. 7iiger in North America, where 

 the species is more variable than it is in Europe. 



8L Las'ius {Formicina) hrevicornis Emery. 



Montana: Elkhorn (W. M. Mann). 



Colorado: Cheyenne, Canyon, near Colorado Springs (Wheeler). 



New Mexico: San Geronimo (Mary Cooper). 



This species, which is very common under stones on dry sunny hill 

 slopes in New England and New York, is rare in the Western States. 



The worker specimens from Colorado and New Mexico approach 

 those of the following subspecies in the shape of the petiolar node 

 and in having slightly smaller eyes than the typical form, but the 

 differences are not sufficient to justify a new varietal name. 



82. Lasius {Formicina) hrevicornis subsp. microps subsp. no v. 

 Worker. Differing from the typical hrevicornis in the much smaller 



