Bui. 194, U. S. Dept. of Agriculture. 



Plate XI. 



ev'vs. 



"^iLJh: 



Fig. 1.— Hedge Canal, Montana. (No. 161.) 





:^. 



Fig. 2.— Birch Canal, Imperial Valley, California. 



(No. Ki'J— iJowiiMlrciiiii from MeU:r Htutioii 6.) 



