PLATE 73. 



Aulopora edithana. Devonian. 



1. Corallum incrusting the dorsal valve of Strophomena hemispherica, 



from the rotten hornstone of the Middle Devonian, Falls of the 

 Ohio. Collection of the author. 



Ro.mixgeria incrustans, Nov. Spec. Devonian. 



2. Corallum, somewhat eroded, incrusting Cyathophyllum pocillum. 



3. Under surface and lateral view of a corallum. 



4. Upper surface of a corallum. 



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

 author. 



Atlopora pygmcea, Nov. Spec. Niagara. 



5. Corallum incrusting Thecia swindernana, from the Upper Niagara 



white clay, near Louisville. 



6. Example incrusting Stromatopora concentrica, from the Upper Ni- 



agara red clay, near Louisville. 

 Collection of the author. 



Aulopora cornuta. Devonian, 



7. Corallum incrusting interior and margin of calyx of Cyathophyllum 



corniculum, from, the Middle Devonian, Falls of the Ohio. Col- 

 lection of the author. 



8. Corallum incrusting fragment of Cyathophyllum scyphus, from the 



Upper Devonian dark red encrinal limestone clay, near Louis- 

 ville. Collection of Mr. Graines. 



Aulopora culmula, Nov. Spec. Devonian, 



9. Corallum incrusting a jejune frond of Favosites clausus, from the 



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



Nicholsonia (Nov. Gen.) canadensis. Devonian. 



10. 11. Corallets incrusting a Fenestella, from the rotten chert of the 

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

 [The corals and bryozoa both being white, the photographic deline- 

 ation of the former is unsatisfactory, although the examples are 

 good.] 



Aulopora procumbens, Nov. Spec. Devonian. 



12. Corallets incrusting a species of Stromatopora, from the Lower 



Devonian ferruginous clay, near Louisville. Collection of the 

 author. 



13. Corallets similarly incrusting Stromatopora, from the horizon and 



place of example 12. Collection of Mr. McConathy. 



