GEOLOGY AND PALEONTOLOGY OF THE SCHOHARIE VALLEY 287 



the Marcellus shown in small draws, but the 

 greater part of the slope is covered by soil so 

 that it is impossible to determine the line of 

 division between the Marcellus and Hamilton 

 formations. Again in the Helderberg regioD 

 there is a gradual change in the lithologic char- 

 acters from the Marcellus to the Hamilton, and 

 tin* Marcellus shales have a greater thickness 

 than in central and western New York. It is 

 probable that the upper part of the hill belongs 

 in the Hamilton formation. To the southwest 

 across one of the head branches of the Onis- 



