104 Psyche [June 



Lasius brevicornis Emery. — A single nest found at Pullman, 

 Wash. 



Lasius (Acanthomyops) interjectus Mayr. Common near 

 Pullman. Many nests were examined, some of them repeatedly. 

 The only guests were a pair of Adranes taylori, taken March 22. 



Lasius (Acanthomyops) latipes. — One nest, found under a 

 stone on the banks of the Snake River, at Wawawai, contained 

 eleven specimens of Adranes taylori and one of TribaUus cali- 

 fornicus. Though the latter beetle is often found in ant nests, it 

 is as frequently found away from them, and is doubtfully com- 

 mensal. 



Formica sanguinea subsp. subintegra Emery, and Formica 

 subpolita var. picea Emery. — A mixed colony found under a 

 stone in the vicinity of Pullman, Wash. 



Formica sanguinea subsp. subnuda Emery, and Formica 

 dakotensis Emery. — Mixed colonies abundant at Troy, Idaho, 

 in May and June, nesting in rotten logs and stumps. 



Formica rufa subsp. obscuripes Forel. — This, the common 

 mound-building ant of the Northwestern states, is the most con- 

 spicuous ant in eastern Washington. Several large colonies, 

 located on the campus of the State College, were regularly examined 

 throughout the spring. March 1, I took with this ant a single 

 specimen of Platymedon laticollis Casey. This brightly colored 

 little staphylinid was later found common in most of the mounds 

 examined, and may be considered as the characteristic inquiline 

 of that ant in Eastern Washington. It was found in all parts of 

 the nests, generally where the ants were thickest and in no 

 instance did I observe the ants to molest or even notice it. 



The most interesting find with obscuripes was a species of 

 Aphodius. Three specimens were taken on March 5 from a popu- 

 lous nest, which had been previously baited with a piece of board. 

 Although the allied genus Euparia is an ant guest, no Aphodius 

 has been recorded as myrmecophilous, so the occurrence of these 

 three specimens was thought accidental. The board was carefully 

 examined and replaced on the nest. The next day another of the 

 beetles was taken, and specimens continued to turn up until March 

 18. In all eight were taken from the one nest. 



The finding of this species, belonging to a genus normally 

 coprophagous in habit, in an ant nest may seem too slight an 



