20 PROCEEDINGS OF THE ACADEMY OF [1881. 



Spanish bayonet, low cedars and pine, and in the little vales or 

 nooks wild sunflowers, wild roses, and numerous small thickets 

 and clusters ol' a scrub oak (Quercus undulata). These localities 

 are indicated diagramatically in the sketch-map at Fig. 1. 



All along the tops of these ridges, and on the eastern and 

 south-eastern slopes, the nests of the Honey Ants arc located 

 (PL I, fig. 2 ^). About ninety per cent, of those found were on 

 the tops of the ridges, and every one on or near the summit or 

 central line of the top. The choosing of such a site may, there- 

 fore, be inferred to be a fixed habit of the ant. 



The advantage of this location is apparent, at least in the 

 points of dryness and warmth. I made several observations of 

 the effects of the heavy July and August rain storms upon the 

 exterior architecture, which is a low, gravel-covered moundlet, 

 penetrated at the centre by a tubular gallery or gate three-fourths 

 of an inch in diameter (PI. II, figs, 3, 4). The large gravel-covered 

 mounds of the Occidental Ant {Pogonomyrmex occidentalism Cres- 

 son), numbers of which were built in the vallej^ of the Boiling 

 Fountain Creek, and in the nooks between the ridges, were more 

 or less damaged by the wash of the water. Some were seriously 

 injured, one wholly swept away. The only damage wrought upon 

 the Honey Ant nests was a little beating down of the pellets of 

 gravel within the gate. There was no injury from the wash of the 

 water, and apparently no likelihood of any beyond that which the 

 momentum of the rain-drops could inflict as they dashed upon the 

 nest and within the gate. Throughout one storm, during the 

 entii'c progress of which a nest was watched, several ants were 

 stationed like sentinels within the gate around the upper margin 

 (PI. Y, fig. 25). They were evidently on the look out for any 

 damages to their home. The disarrangement of a few pellets 

 moved two of these sentinels to bring up bits of gravel and 

 attempt repairs. But there was little occasion for this, although 

 the force of the rain was great enough to cause a good deal of 

 discomfort to the observer. In half an hour the rain ceased, the 

 sun came out over Pike's Peak, and a rainbow girdled the Mesa. 

 One worker-major crawled upon the crest of the nest, stretched 

 herself, reared her head as though to snuff the fresh air, then 



1 This is a sketch of my camp, from the point at which the Adams and 

 Von Hagen ridges meet. One of the ant-nests is seen in the foreground ; 

 others are indicated by the white circles on the crests of the ridges. 



