1905.] Wheeler, Ants of the Genus Dolichoderus. 317 



pot-shaped cavity from 12-18 inches in depth and 3-5 inches in 

 diameter, (Plate XIII, Fig. 2.) The spaces between the root-fibres 

 serve as galleries and in them the larvae and pupae are kept. The 

 withdrawal of so much sand from the roots of the grass often 

 destroys the vigor of the plant and prevents it from flowering. 

 Bits of dead leaves, pine-needles, etc., are heaped over the sur- 

 face between the grass-blades sometimes in sufficient quantity to 

 form a flat mound, but quite as often the top of the nest is concave 

 owing to the withdrawal of the sand and its being only partially re- 

 placed by vegetable debris. One large nest of gagates about ten 

 inches in diameter was seen in the open woods surmounted by a 

 flat mound consisting exclusively of flakes of charred pine bark 

 which the ants had collected and placed not only on the top of the 

 nest but between the root-fibres to a depth of a foot. On warm, 

 sunny days, the workers bring their brood so near the surface that 

 the maturer pupae may be exposed to the light, while the ants them- 

 selves bask in the sun in a great mass among the bases of the grass- 

 stems. At such times a gagates colony sparkles like a mass of jet 

 beads and a colony of marice is even more beautiful, as it reflects the 

 sunlight from thousands of bright -red and blue-black bodies. 



The nests are most easily located by first finding the ants on the 

 foliage of some one of the numerous oaks (Quercus nana, ohtusiloha, 

 marylandica, prinoides, etc.) or pines (Pinus rigida and inops) so 

 characteristic of the barrens. A few hundred gagates or maricB may be 

 seen attending aphides or coccids (Chcrmes) on a branch of one of 

 these trees and thence traced in an uninterrupted file descending the 

 trunk and moving over the white sand, dead leaves, and pine-needles 

 sometimes a distance of 30-50 feet to the nest. Often several files go 

 out from the same nest in different directions to as many different 

 trees. From the large gagates nest above described six files were seen 

 radiating and traversing the barren ground for distances varying 

 from 20 to*4o feet before they reached their respective trees. 



Although these ants subsist very largely on the excrement of 

 plant-lice and coccids, they are also very fond of insect food. A 

 caterpillar or dead insect dropped near one of their files is soon com- 

 pletely covered with ants and devoured in situ. It is probable 

 that the aphides and coccids within a radius that can be con- 

 veniently patrolled by a single colony are far from being sufficient 

 to supply its thousands of workers with food. Hence the colonies 

 must from time to time move to new localities and excavate fresh 

 nests. That this is not infrequently done is shown by the following 



