1894. PROCEEDINGS OF THE NATIONAL MUSEUM. 315 



about 1| miles NE. of Schodack depot, in the townsliip of Schodack, 

 and in great abundance in tlie gorge of the Poestenkill, If miles east 

 of Troy, near the Eagle Mills road, along the right bank of the river, 

 which there flows south. The Oldhaniia is here associated with various 

 trails, and both cover large surfaces of the rock. 



The slates are post-Lower Cambrian and pre Trenton, but their exact 

 stratigraphic position is not fully determined. They are either Upper 

 Cambrian or Lower Ordovician. 



