GEOLOGY AND PALEONTOLOGY OF THE SCHOHARIE VALLEY 



159 



this period the near shore sand and pebble beds of the lower 

 Oriskany were deposited in the Rondout region and southward 

 iind the low^er Oriskany beds of Becraft mountain were deposited 

 probably at a greater distance from the shore, so that the 

 silicious element in them became much reduced. As has been 

 shown elsewhere^ the Oriskany of Becraft mountain is a continu- 

 ous series with the Helderbergian series, the calcareous Port 

 Ewen beds of that locality forming a complete transition from the 

 one to the other. 



Fossils of the Oriskany formation 



Brachiopods are the most characteristic fossils of this forma- 

 tion. One of the most striking is H i p p a r i o n y x p r o x i m u s 



Fig. 75 Hipparionyx proxiraus 



[fig. 75] with its extremely convex brachial and nearly flat pedicle 

 valves, the latter with strong muscular impressions, which have 



^Stratigraphy of Becraft mountain. 



