206 Vaiighan — Addition to Maryland Coral Fauna. 



the first compound coral that has been found in the Eocene of 

 Virginia and Maryland, and shows a northward range of an Ala- 

 baman species. The physical conditions, however, apparently 

 were not favorable for luxuriant growth. Two factors were 

 probably active. Apparently the Aquia deposits were laid down 

 in water somewhat deeper than those of the same age in Ala- 

 bama. More probably the most important factor was the colder 

 temperature in the Maryland-Virginia region. Both deep water 

 and low temperature are detrimental to a development of colonial 

 corals, especially those that tend to be somewhat or pi-onouncedly 

 massive. 



The sjjecies previously known from the Aquia formation are: 

 Flabellum^^., Turbinolia acuticostata Vaughan, Trochocyathus 

 clarkeanus Vaughan, Paracyathus mar ylandicus Vaughan, 

 JBalanojyhyllia desmophylln7n Milne Edwards and Haime, and 

 EupsaTn7nia elahorata (Conrad). Only the last two species were 

 known to occur also in Alabama. The Flahellum may be drop- 

 ped from the list, as it could not be specifically detei-mined. 

 Now of the six determined species (including the addition of 

 Maimesiastrma conferta), we have three common to the 

 Aquia formation of Virginia-Maryland and the Gregg's Landing 

 horizon of Alabama. 



