No. 415.] NESTS OF AMERICAN ANTS. 52I 
when a break in the herbage compelled them to descend. 
hg traveled in single, or ‘Indian’ file, one behind another. 
. . The specimens which I preserved were taken from 
a small colony found within the bounds of a large Barbatus 
formicary which was being excavated. The agriculturals took 
no notice of their tiny neighbors, at least never interfered with 
them, and the two species seemed to be upon the most friendly 
terms with each other.” 
McCook’s observations are, in the main, correct, so far as 
they go, but they are so incomplete as to give a wrong concep- 
tion of the habits of Forelius. This ant is extremely common 
at Austin, where McCook made the above-quoted observations. 
It really prefers dry soil, nearly or quite destitute of vegeta- 
tion. It throws up its little crater-shaped mounds of earth in 
great numbers along the paths and roads, and on warm sunny 
days travels in straggling files over all the barren lands. 
Sometimes, however, it nests under stones on the dry hill- 
slopes, and it is in such situations that one often finds the 
largest and most flourishing colonies, containing many deálated 
queens and thousands of workers, larvae and pupz. The fact 
that it often builds within the confines of the Pogonomyrmex 
formicaries is easily explained, for, though the agricultural ant 
naturally prefers grassy regions, nevertheless, through its sin- 
gular habit of clearing away the vegetation over a large 
circular area, it establishes the very conditions that are pre- 
ferred by the Forelius. The “ friendly relations" with Pogo- 
nomyrmex are perhaps to be explained by the very small size 
and active movements of Forelius, which thus escapes the 
attention of its huge neighbors. In this respect the dolicho- 
derines seem to be in the same position as the small white 
podurans (Cyphodeira), which run about unheeded in the 
galleries and chambers of the Pogonomyrmex nests. 
5. Dorymyrmex pyramicus Roger. 
In connection with some rather fanciful passages from the 
Manuscript of Lincecum, McCook (79, p. 197 et seg.) records 
Several observations of his own on the relations of Dorymyrmex 
