ANTS. 



Colorado Springs. It took place on a clear afternoon and resembled 

 in nearly all respects the nuptial flight of inolefaciens described above. 

 During the .summer months of 1906 1 saw dealated females founding 

 their colonies in the rocky plains about Buena Vista, Colorado. The 

 female enters the soil obliquely, throwing the earth backward with her 

 legs or carrying it out with her mandibles till it accumulates in the form 

 of a small fan-shaped mound as in inolefaciens and californicus. I 

 have inferred the manner of growth of the crater from examination of 

 many nests of different sizes and ages, and represent the process in the 

 accompanying diagram (Fig. 165). A and A' show in surface view and 

 section respectively the nest as dug by the dealated queen, .r being 

 the opening and s the cell in which she brings up her first brood of small 

 workers after closing the entrance. The moundlet of excavated earth 

 is soon disintegrated by the wind or rain. When, during the following 

 spring, the young brood break out to the surface, they construct a 

 crater like B and B'. This corresponds to the permanent nests of such 

 forms as P. coniancke, californicus and badius. Gradually, however, 

 the wall of the crater back of the slanting entrance is built up more 

 rapidly than the wall in front, till a cone is produced with the .opening 

 near the base on one side (C and C'}, and as it grows the chambers are 

 extended up into it from the underlying soil. This is the adult form 

 of the nest and is not represented in the sand-inhabiting species men- 

 tioned above. P. inolefaciens also presents a stage like B and B', but 

 the opening is perpendicular and the crater rim grows uniformly around 

 its whole periphery and often to a much greater height. B and B' may 

 also be taken to represent on a large scale the permanent nest-form of 

 the small species of the genus, P. dcscrtorum, Ephebomyrmex hnbcr- 

 biculus, etc. 



A good account of the distribution and nesting habits of P. occi- 

 dcntalis in the higher, western portion of Kansas has been published 

 by Headlee and Dean. These authors give measurements of the nests 

 and interesting figures of their architecture. One of these figures is 

 here reproduced with Mr. Dean's permission (Fig. 164). 



In conclusion, attention may be called to the stinging habits of 

 Pogonomyrmex. In this respect the smaller and more timid species 

 are no more formidable than other Myrmicine ants of the same size 

 dwelling in small colonies. But this is not the case with P. occidcntalis, 

 P. borbatns and the allied varieties and subspecies. The sting of these 

 ants is remarkably severe, and the fiery, numbing pain which it pro- 

 duces may last for hours. On several occasions when my hands and 

 legs had been stung by several of these insects while I was excavating 

 their nests. I grew faint and almost unable to stand. The pain appears 



