PLATE 11. 



Favosites hemisphericus, et vaeietates. Devonian. 



1. Lateral view of a weathered example, showing corallet walls incras- 



sated hy siliceous deposits during fossilization, from the Middle 

 Devonian, near Louisville. Collection of the author. 



2. Vertical section of an example from the same locality. Collection of 



the author. 



3. Lateral view of a corallum from the same horizon, near Louisville. 



Collection of the author. 



4. Conical section, parallel with the operculous exterior, from the same 



horizon and place. Collection of the author. 



5. 6. Lateral views of sub-bacillate forms, from the upper clay beds of 



the Middle Devonian; near Louisville. Collection of the author. 



7. Lateral view of a corallum, whose operculous apex has been flattened 



by attachment to a marine object; from the locality of 5 and 6. 



8. Portion of a corallum from the dark red clays derived from the de- 



composition of the encrinal limestone lying under the shale which 

 caps the Devonian; near Louisville. Collection of the author. 



9. Lateral view of a distorted example formed by two sub-bacillate 



forms intimately united; from the horizon of 5 and 6, near Lou- 

 isville. Collection of the author. 



