MOUNTAIN ANTS OF NORTH AMERICA. 541 



very brief description of the var. ruhiginosa. The only difference I can 

 detect between this form and the typical obscuriventris is the greater 

 infuscation of the thorax and petiole of even the largest workers. 

 Emery records the form from Nebraska, Colorado and Dakota. 



120. Formica foreliana Wheeler. 



Known only from the Huachuca Mts., Arizona, where it was taken 

 by Mr. C. R. Beidermann at altitudes between 4500 and 5G00 feet. 



121. Formica ciliata Mayr. 



Colorado: West Cliff, 7864 ft. (T. D. A. Cockerell). 



Recorded from various localities in Colorado and Montana. 



Several workers taken by Mr. E. J. Oslar in the San Miguel Mts. of 

 Colorado at an elevation of 11,000 ft. seem to belong to this species, 

 but the head is covered with short erect hairs and not naked as in 

 typical ciliata. As there is a possibility that these specimens may 

 represent a new species with aberrant female form like ciliata, comata, 

 criniventris, etc., I await further material before introducing another 

 name. 



122. Formica comata Wheeler. 

 Known from Colorado and South Dakota. 



123. Formica criniventris Wheeler. 



Recorded from Boulder, Colo, and Helena, Montana. 



124. Formica oreas Wheeler. 



Taken in various localities in Colorado and New Mexico. 



125. Formica oreas Wheeler var. compiula W^heeler. 

 Known from Pullman, Washington and Elkhorn, Montana. 



126. Formica dakotensis Emery. 

 Alberta: Banff (Wheeler). 



Colorado: Creede, 8844 ft. (S. J. Hunter). 



Previously known from South Dakota, British Columbia and Nova 

 Scotia. 



127. Formica dakotensis var. montigena Wheeler. 

 Montana: Nigger Hill, Powell Co. (W. M. Mann). 

 Recorded from Colorado, New Mexico, Montana and Idaho. 



