GEOLOGY AND PALEONTOLOGY OF THE SCHOHARIE VALLEY 293 



7 Pteriuea flabelluni (Con.) H. r 



8 Nyassa arguta H. aa 



9 Leptodesma rogersi H. rr 



10 Actinopteria subdecussata H. rr 



11 Liopteria dekayi H. rr 



12 L. bigsbyi H. rr 



13 Palaeoneilo maxima (Con.) H. rr 



14 p. constriota (Con.) H. r 



15 Modiomorpha concentrica (Con.) H. rr 



16 Tentaculites bellulus H. (?) rr 



oj I Sea Level _ 



Fig. 203 Section of escarpment near Clarksville. (After Prosser) 



Feet Total 



Marcellus shales 300-771 



Black argillaceous shales with dark slightly cal- 

 careous sandstones. In a gully in the rear of the 

 house of Elias Mathias the upper 200 feet of 

 this formation are well exposed as well as its 

 gradual transition to the arenaceous shales of 

 the Hamilton. The lower 100 feet or more of 

 this formation are covered, after that there are 

 about 80 feet of black, argillaceous shales, then 

 about 30 feet of shales of this character inter- 

 spersed frequently with layers of slight lv cal- 

 careous, dark sandstone, above which are 85 

 feet of dark, argillaceous shales. It is rather 



