PLATE 3. 



Lyellia papillata. Niagara. 



1. Portion of the upper surface of a corallum from the ferruginous clay 



just below the Niagara and Devonian passage-beds, near Louis- 

 ville. Collection of the author. 



Lyellia Americana. Niagara. 



2. Upper surface of a corallum from the white clay ten feet below the 



Niagara and Devonian passage-beds, near Louisville. Collection 

 of the author. 



