PLATE 4. 



Cladopora labiosa. Middle Devonian. 



1. Front lateral view of the upper fronds of a corallum imbedded in 



rock matrix, from the Falls of the Ohio. Collection of the author. 



Lyellia discoidea, Nova Species. Niagara. 



2. Convex upper surface of a corallum from the white clay, near Lou- 



isville. Collection of the author. [The example figured is ex- 

 quisitely preserved, but its color seems to have prevented good 

 photographic delineation.] 



3. Plane upper surface of a corallum, found near Louisville. Collection 



of Dr. J. Knapp. 



Lyellia papillata. Niagara. 



4. Lateral view of a weathered corallum showing the vesiculose ccenen- 



chyma, found near Louisville. Collection of the author. 



Cgexites lamixata. Niagara. 



5. Upper surface of a weathered corallum from the white clay, near 



Louisville. Collection of the author. 



Ccexites crassa. Niagara. 



6. Upper surface of a corallum from the ferruginous clay just below the 



Niagara and Devonian passage-beds, near Louisville. Collection 

 of the author. 



