222 
Psyche 
[December 
3. Pheidole oregonica Emery 
P • oregonica occupies the same habitats as does P. Cali- 
fornia, but its colonies are usually less populous. 
4. Leptothorax curvispinosus rugatulus Emery 
This ant is rather frequent in moist habitats near Twin 
Falls, Hagerman and Buhl, chiefly along the Snake River. 
Colonies are small, the workers timid and sluggish and the 
brood scant. Winged forms appear at Twin Falls in late 
September. 
5. Leptothorax eldoradensis Wheeler 
The species eldoradensis occurs in small numbers near 
Twin Falls, where it occupies small crater nests in moist 
areas. 
6. Monomorium minimum Buckley 
Occurring in small numbers, this species occupies either 
minute crater-nests or nests beneath fallen timber and loose 
rocks. The populous colonies often contain several queens 
each. Winged forms appear in the nests from the middle of 
June to late August. 
7. Monomorium pharaonis L. 
One colony of this species was found under a house near 
Twin Falls. This locality is decidedly out of its normal 
range. 
8. Solenopsis molesta Say 
This ant is occasionally found beneath rocks in moist 
habitats throughout southern Idaho, and is usually observed 
in the superficial nest chambers of other ants ( Formica 
fusca subsericea and F. fusca neorufibarbis Emery). 
9. S. molesta validiuscula Emery 
Much more abundant than the typical species, colonies of 
this variety are widely scattered throughout the region un- 
der discussion, but make their appearance only in moist 
areas. The nests are similar to those of the typical molesta 
but are more isolated and of smaller size. 
