762 



Bidldin American Miiseitm of Natural History. \yo\. XXIII, 



.sino;le gallery. The internal structure of the nest resembles on a small 

 scale that of Trachipnyrmcx turrifex. It consists of from two to four alter- 

 nating vertical galleries and spheroidal chambers. As the former are very 

 tenuous and run through pure sand, the excavation of the nests is rather 



Fig. 27. Section of nest of Atta (Myretosoritis) hnrtmanni in pure sand at Delvalle, Texas. 

 About I natural size. (Pliotograpii by Mr. C. G. Hart maim.) 



difficult. The measurements of six of these nests (S to X) are given in the 

 accompanying table, diagrams of three of them are represented in Figs. 

 30-32, PI. LI, and photographs of portions of one of them in Figs. 27 and 

 28. 



