PLATE 106. 



Ptychophyllum TRorcEUM, Nov. Spec. Devonian. 



1. (Lower right specimen.) Anterior view of a corallum of average 



size. 



2. (Lower central specimen.) Posterior view of a corallum. 



3. View of the calyx of a large corallum. 



From the Lower Devonian rocks, Falls of the Ohio. 



Ptychophyllum diaphragm a, Noi pec. Devonian. 



4. (Lower left specimen.) Left lateral view of an adult corallum. 



5. View of the calyx of a corallum, with portion of the right wall 



fortuitously broken. 

 From the horizon and vicinage of the preceding species. 



Ptychophyllum typicum, Nov. Spec. Devonian. 



6. Right lateral view of a corallum, from the Middle Devonian clay 



of Lincoln county. 



7. View of the calyx of a corallum, from the blue clay of the Middle 



Devonian, Falls of the Ohio. 



Ptychophyllum contferum, Nov. Spec. Devonian. 



8. (Right of center.) Right lateral view of a corallum, from the 



Lower Devonian clay of Lincoln county. 



9. (Left of center.) Posterior view of a corallum, from the Lower 



Devonian rocks, Falls of the Ohio. 



10. Right lateral view of a corallum. 



11. (Upper central specimen.) Right lateral view of a corallum, with 



calyx wall broken down so as to show the sub-vesicular cen- 

 tral cone. 



Examples 10 and 11 are from the horizon and vicinage of exam- 

 ple 9. 



The specimens figured in the Plate are from the collection of the 

 author. 



