PLATE 106. 



Ptychophyllum trop(eum, Nov. Spec. Devonian. 



1. (Lower right specimen.) Anterior view of a coralluni 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 diaphragma, Nov. Spec. Devonian. 



4. (Lower left specimen.) Left lateral ^•iew of an adult corallum. 



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



fortuitously broken. 

 From tlie 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 coniferum, 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 fi'om the horizon and vicinage of exam- 

 ple 9. 



The specimens figured in the Plate are fi'om the collection of the 

 author. 



