33^ Bulletin American Museum of Natural History. [Vol. XXI, 



nest. June lo, 1902, I happened on a huge nest of this species on 

 the "Crouching Lion" at Ft. Davis. It was fully two feet long and 

 a foot and a half wide, and was situated in the ground under a large 

 flat stone. A year or two previously the stone must have rolled down 

 a slope onto some coarse grass and twigs and the ants had built up the 

 earth in the interstices between these vegetable remains and com- 

 pacted it with some glandular secretion till it formed a huge mass of 

 trabeculae, much coarser and with larger openings but otherwise 

 similar to that figured by Mayr for the European species. The nest 

 contained thousands of workers and fully a quart of glistening white 

 worker larvae and pupae. The ants attacked me with great fury and 

 nearly suffocated me with their intense butyric acid odor. This nest 

 was situated in an open stony region at least 200 feet from the nearest 

 trees. Another smaller nest of similar construction was found under 

 a stone in the Paisano Pass, near Alpine, Texas. The specimens of 

 apiculatum collected by Mr. C. H. Tyler Townsend on the volcano of 

 Colima are also from a "large nest in the ground and dead leaves under 

 a log." That these insects habitually build in the soil is also shown 

 by the fact that on four different occasions, twice at Ft. Davis and 

 twice near Manitou, I came upon isolated females in the act of 

 establishing their colonies in small cavities excavated in the soil under 

 stones in rather open places. One of these insects had a packet of 

 eggs, another a packet of larvas, and a third, that had recently died, 

 probably from hunger or exhaustion, was being devoured by a colony 

 of a small species of Solenopsis allied to 5. validiuscula Emery. These 

 huge females, with the exception of the females of Atta fervens and 

 our larger Camponoti, the largest and most obese of their sex among 

 North American ants, are thus seen to establish their colonies in the 

 same manner as the vast majority of Formicidas. 



While collecting in Colorado during the summer of 1903, I made 

 repeated attempts to get at the nests of Liometopum, which was 

 very common in the Garden of the Gods, where it prefers the red 

 volcanic rocks and soil just as it does in the Paisano Pass and at Ft. 

 Davis. The files of ants were often seen disappearing under rocks, 

 but when these were lifted in the hope of finding their nests, it was 

 found that only a runway or perhaps a succursal nest had been un- 

 covered. In vain rocks were removed over large surfaces, only to 

 find the burrow at last disappearing into the ground under the roots 

 of some great tree, immovable boulder or cliff. The fact that in 

 these runways the ants often congregate in numbers, together with 

 the myrmecophilous beetles mentioned below, is apt to lead the ob- 



