EXPLANATION OF PLATE 23 



Fig. 1. Manix beds two miles south of Field, dissected by the back- 

 cutting of gulches tributary to the Mohave Eiver. View shows evenness 

 and persistence of bedding, the type of topography developed by erosion, 

 and the original lake-bed surface at the skyline. 



Fig. 2. Manix beds three miles south of Field. Course of Mohave 

 River is cut down forty to fifty feet. On left are Cady Mountains. 



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