

CONTENTS 



Prefatory note 5 



Introduction • 6 



Chapter 1 



Stratigraphic structure of Becraft mountain .... 6 



Chapter 2 



Description of the fauna ...... . 15 



Vertical range of species ..... . 65 



Faunal values of species 68 



Chapter 3 



Nature and distribution of the Oriskany fauna in New York 72 



Distribution of the calcareous facies ..... 72 



Ulster county ......... 72 



Orange county ......... 75 



Albany and Schoharie counties ..... 77 



The original Oriskany sandstone 78 



Fauna of the Gaspe limestones 80 



Chapter 4 



The Devonic age of the Helderbergian fauna and the base 



of the Devonic system in New York .... 82 



1 the argument from correlation . . . . 



2 the argument from the intrinsic character of the fauna 



3 the argument from stratigraphy . . . ... 95 



Fauna of the Manlius limestone ..... 98 



Explanation of plates 103 



Index , • • • 122 



83 

 83 



