Hills, Valleys and Plain s of the U. 



THE IVES ALTITUDE MAP 



previously published, 



Aid in the Study of Geology. 



THE IVES STRATA MAP 







., 





JAMES T. B. IVES, F. G. S. 



OPINIONS OF EMINENT AUTHORITIES. 



JAMES T. B. IVES, 

 Office of the American Naturalist, 



518 Minor Street, Philadelphia, Pa. 



