1934 ] Ants of the Snake River Plains 225 
It was beneath a large flat rock on a dry sagebrush-covered 
hillslope in the Snake River Canyon, near Twin Falls. 
24. Myrmecocystus melliger semirufus var. 
Numerous crater nests, about six inches in diameter, pre- 
dominated in a semidesert sand dune area near Indian Cove, 
and have also been found on sand hills near Buhl. The pop- 
ulous colonies contained both males and females in early 
June at Indian Cove. Repletes were not present. 
25. M. yuma Whir. 
Many small crater nests of fine sand were found on a 
sagebrush plain near Hammett. The workers were very 
active. Winged forms appear in the nests during early 
July. Repletes were not found. 
26. M. mexicanus var. 
Sandy crater nests of an undescribed variety of mexicanus 
abounded in a sandy area near Indian Cove. Other localities 
include Hollister and Twin Falls. Males and females ap- 
peared in the nests in early June near Indian Cove and in 
late June near Twin Falls. True repletes were not present 
in the nests. 
27. Camponotus maculatus vicinus nitidiventris Emery 
This variety abounds beneath rocks in the more moist 
places of the sagebrush plains and in wooded areas of aspen 
and western yellow pine at higher elevations. The colonies 
are large and the workers active. Males and females appear 
in the nests throughout June and July near Twin Falls. I 
have taken this ant as far north as Boise. 
28. C. hyatti Emery 
A very few colonies of this species were beneath rocks on 
rather moist sagebrush and bromegrass-covered hillslopes 
near Twin Falls. 
29. C. modoc Whir. 
This species is abundant in pine and aspen groves south 
of Rogerson. It inhabits nests in moist, rotting logs. 
