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C. R. STAUFFER 



the Hamilton beds exposed along Aux Sable River in Ontario. The 

 general make-up, appearance, and physical properties of the shale 

 below the Prout limetsone and the Olentangy shale are the same 

 (Figs, i, 2, and 3). Moreover, the Delaware limestone, which 

 underlies this deposit at Delaware and at Sandusky, carries the 



Fig. 1. — A weathered bunk of fossiliferous Olentangy shale showing one of the 

 common calcareous layers in this shale along Plum Creek, near Prout station. 



FlG. 2. — A bank of Olentangy shale along the Olentangy River at Delaware, 

 Ohio. The limestone disks in this bank contain an occasional fragmentary fossil. 

 The lens of crinoidal limestone was found at this locality. This is Winchell's type 

 locality for the Olentangy shale and shows its marked contrast to the Ohio or even to 

 the blue bands occurring in the middle portion of the latter. 



same fauna at both places and extends northward into Ontario. 

 Whitfield found the lower part of the Delaware to be the western 

 extension of the Marcellus shale, to which he considered it to be in 

 part equivalent. 1 Wherever the Delaware limestone becomes 



1 R. P. Whitfield, /'••. of the American Association for the Advancement of 



Science, XXVIII (1879), :oS - 



