THE PRINCIPLES OF STRATIGRAPHY 



By AMADEUS W. GRABAU, S.M., S.D. 



Professor of Palaeontology in Columbia University 



"This monumental work will be of great value especially to the 

 younger generation of American Geologists, in broadening their 

 mental horizon and outlining the problems which rise for solution 

 in the twentieth century study of the rocks. It differs from other 

 manuals in the English language to such a degree that it 

 supplements but does not supplant them." — Science, July 14, 19 14. 



8vo, 1150 pages, 264 illustrations. Price $7.50 



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A new series — volume II, No. 1. The Structure and Relationship of Diplocaulus. 

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No. 1. The Vertebrates from the Permian Bone 

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No. 4.* New or Little-known Vertebrates from 

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