ii6 Carl O. Dunbar. 



this period they appeared only sporadically in the Appalachian 

 trough, several specimens of Camarocrinus having been found in 

 the Manlius of New York, while these anchoring bulbs are com- 

 mon at one thin horizon in the Keyser of Maryland. In other 

 respects, the fauna of the Olive Hill formation is largely made 

 up of species which continue into the succeeding Birdsong forma- 

 tion, and the chief difference in these faunas is the sudden 

 appearance in the Birdsong shale of many new species, the typi- 

 cal New Scotland facies, which now come to mingle with those 

 already present in the Ross limestone. 



The Oriskany faunas of the Quail and Harriman formations 

 again show an advent of the Appalachian faunas almost 

 unchanged. 



The Camden chert, on the other hand, has a fauna distinctive 

 of the southern embayment, which occupied practically the same 

 position as that of Helderbergian time. It was only during the 

 deposition of the almost immediately succeeding Pegram lime- 

 stone that communication with the Appalachian seas was again 

 established, and the Onondagan coral faunas attained western 

 Tennessee. The evidence for the Onondagan age of the Camden 

 chert is fully presented in the larger paper mentioned above. 



The study of these Devonian faunas was made in the paleon- 

 tological laboratories at Yale University, and the types of the 

 new species here described are the property of the Peabody 

 Museum. The writer wishes to acknowledge his indebtedness 

 to Professor Charles Schuchert for helpful criticism in the 

 preparation of the paper. 



