288 AMERICAN HYMENOPTERA. 



yellow pile ; fifth segment sometimes with a very few black hairs mixed 

 in with the yellow ; sixth segment often entirely covered with yellow 

 pile, but as often with a more or less strong sprinkling of black hairs 

 on the middle portion ; apical segment mostly black, but usually with 

 a more or less noticeable light tuft toward each side. Venter, except 

 basal and apical segment, bearing whitish pile for the most part. 



Genitalia. — Outer spatha with a variable (usually scattering) tuft of 

 hairs on each side of the apical portion of the ventral surface (fig. 

 138). Basal part of head of sagittse perforate close to the shaft. 



Wings. — Colored about like those of the worker though, as a rule, 

 somewhat lighter, distinctly lighter than those of the queen, only 

 slightly stained with brown. 



Legs. — Posterior coxae bearing more or less whitish pile ; all the 

 trochanters and femora bearing a large amount of whitish pile and, as 

 a rule, very little dark pile, except the fore and middle femora in front 

 and the posterior femora behind and all the femora around very distal 

 ends ; tibiae all dark. 



Dimensions . — Length : queens, 14 mm. to 20 mm. ; workers, 10 

 mm. to 14 mm. ; males, 12 mm. to 17 mm. Spread of wings: queens, 

 35 mm. to 42 mm. ; workers, 24 mm. to 35 mm. ; males, 30 mm. to 33 

 mm. Width of abdomen at second segment : queens, 8 mm. to 9J 

 mm. ; workers, 6 mm. to 8 mm. ; males, 6| mm. to 1\ mm. 



Redescribed from twenty queens (two of them homo- 

 types), fourteen workers (two of them homotypes) and nine 

 males. 



Habitat. — This handsome species appears to be confined 

 to the mountain ranges and higher lands of the western 

 United States and to the southwestern portion of Canada 

 (probably the lower lands). The most southern records 

 which I have are the Magdalena Mountains and Rio Ruidoso, 

 New Mexico and Chino, southern California. My most 

 northern record is Kelowna, British Columbia, where it does 

 not appear to be rare. My most eastern record is Fort Col- 

 lins, Colorado. I have records from the following states of 

 the United States : Washington, Oregon, Montana (western 

 part), Wyoming, Colorado, Utah, Nevada, California and 

 New Mexico and from British Columbia only in Canada. It 

 appears to be rather a rare species in New Mexico, Colorado, 

 Utah and Nevada and to increase in abundance northwards 

 until it reaches its maximum in western Montana, Idaho 

 (probably), Washington and Oregon, where it appears to be 



