Bui. 211, U. S. Dept. of Agriculture. 



Plate IX. 



Fig. 1.— View in the South-Central Part of New Mexico, Showing a Small 

 Tank in the Foothills. 





'■■if j- <■ 



r3i 



Fig. 2.— View in the Southeastern Part of New Mexico, Showing a Large 

 Tank on the Plains. 



