PLATE 27. 

 Michelinia insignis. Devonian. 



1. View of the epithecatecl under surface of a corallum, showing the 



semi-cylindrical shape of the outer walls ; to the left of the center 

 several of the corallets become temporarily disjunct, but again 

 unite with their neighbors by approximation; from the encrinal 

 limestone clay of the Upper Devonian, near Louisville. Collection 

 of the author. 



Favosites convexus, Nov. Spec. Devonian. 



2. View of the under surface of a corallum from which the epitheca is 



removed so as to show the mural pores and squamous walls; from 

 the ferruginous clay of the Lower Devonian, near Louisville. Col- 

 lection of the author. 



3. (Central small sjDecimen.) View of the under surface of a small 



corallum, covered with a deeply-wrinkled epitheca ; from the Lower 

 Devonian, Falls of the Ohio. Collection of the author. 



Favosites mundtjs, Nov. Spec. Devonian. 



4. Upper surface of a corallum in which the larger sub-rotund tubes are 



more regularly recurring than is common; from the blue clay of 

 the Middle Devonian, Falls of the Ohio. Collection of the author. 



Favosites rotundituba, Nov. Spec. Devonian. 



5. Upper surface of a corallum from the encrinal limestone clay just 



below the shale of the Upper Devonian, near Louisville. Collec- 

 tion of the author. 



Favosites proximus, Nov. Spec. Devonian. 



6. Upper surface of a corallum of expanded discoidal shape, composed 



of corallets whose tubes are above average size; from the ferru- 

 ginous clay of the Lower Devonian, near Louisville. Collection 

 of Dr. Knapp. 



Favosites eximius, Nov. Spec. Devonian. 



7. Lateral view of a corallum of turbinate form, from the dark red 



encrinal limestone clay of the Upper Devonian, near Louisville. 

 Collection of the author. 



