THE ANTS OF NORTHERN COLORADO 219 



Formica rufa L., subsp. rubiginosa Emery (Pine Cliff, Boulder). 



Formica ruja L., subsp. obscuripes Forel (Tolland, Boulder). 



Formica ruja L., subsp. integra Nyl., var. coloradensis Wheeler (Tolland). 



Formica rufa L., subsp. obscuripes Forel var. melanotica Emery (Boulder). 



Formica subpolita Mayr., var. (New Castle, Boulder, Tolland). 



Formica pergandei Emery (Boulder). 



Formica sanguinea Latr. ; subsp. subnuda Emery (Tolland). 



Formica sanguinea Latr., subsp. rubicunda Emery (Tolland). 



Formica fusca L., var. between var. subsericea Say and var. argentata Wheeler (Pine Cliff, 



Tolland). 

 Formica ciliata Mayr. (Boulder). 

 Formica microgyna Wheeler (Boulder). 



Formica pallidefulva Latr., subsp. schaufussi Mayr. (Boulder). 

 Formica pallidefulva Latr., subsp. nitidiventris Emery (Boulder). 

 Formica fusca L., var. neorufibarbis Emery (Long's Peak, 12,500 ft.). 

 Formica fusca, var. neoclara Emery (Boulder). 

 Formica oreas Wheeler (Boulder). 



Lasius (Acanthomyops) interjectus Mayr., small var. ? (Boulder). 

 Lasius niger L., var. americanus Emery (Boulder). 

 Lasius umbratus Nyl., subsp. speculivenlris Emery (Boulder). 

 Lasius niger L., var. neoniger Emery (Boulder). 

 Myrmecocystus melliger Forel, subsp. mendax Wheeler (Denver). 



Subfamily: PONERINAE 

 P oner a opaciceps Mayr. (Boulder). 



Notes on Distribution and Habits 



Cremastogaster lineolata Say. This species is the only one of the genus Cremas- 

 togaster which ranges over the whole United States. It extends up to an altitude of 

 7,000 feet in Colorado. The other species are confined to the southern and southwestern 

 states. The workers are often seen attending masses of coccids or aphids on plants, 

 feeding on the "honey dew" which these insects give off. It has the habit of building on 

 the twigs of plants high above ground "tents" over colonies of these coccids or aphids; 

 hence they are called the "tent-building ants." These tents are enclosures made of 

 agglutinated earth or vegetable matter and often show wonderful workmanship. The 

 workers have a disagreeable odor. 



Dorymyrmex pyramicus Roger. This species occurs at altitudes below 6,000 feet. 

 It lives almost always in barren soil. 



Dorymyrmex pyramicus Roger, var. niger Pergande. This small black ant makes 

 diminutive circular hills in barren soil, \ inch high and about 2 inches, in diameter. It is 

 common at lower altitudes in Colorado. 



Formica crinata Wheeler. The nests are from £-1 foot high and are often con- 

 structed of conifer needles. 



Formica fusca L., var. between subsericea Say var. and argentata Wheeler var. 

 This is a very rapidly moving ant. It is easily disturbed and excited, even by scraping 

 the feet near the nest. 



Formica rufa L., subsp. obscuripes Forel. I have seen this subspecies attending 

 aphids on the leaves of aspen. 



Formica fusca L., var. argentata Wheeler, occurs at considerable elevations, prob- 

 ably above 7,500 feet in northern Colorado. 



