342 
GEOLOGY OF THE FIRST DISTRICT. 
county, eastwards by Schoharie to the eastern brow of the Helderberg mountains; thence 
southeast and south to Kingston. It has not been recognized in the Mamakating valley farther 
to the southwest than Marbletown. This rock is characterized by the impressions of the 
Fucoides cauda-galli, figured above. The rock was called by Dr. Eights the “ Cocktail grit,” 
in consequence of the impressions having some resemblance to the tail of a cock. The im¬ 
pressions are very abundant in many localities. 
5. Oriskany Sandstone. 
Fig. 19. 
1. Delthyris arenaria. 3. Atrypa peculiaris. 5. Internal cast of Delthyris arenaria. 
2. Atrypa elongata. 5. Internal cast of Hipparionix proximus. 
The Oriskany sandstone is generally a hard siliceous grit, which generally approaches chert 
and hornstone in aspect, and is replete with fossils. In some places it is white; in others 
