E. W. Berry—Age of the Dakota Flora. 389 



from time to time by Clark, Stanton, Stephenson and the 

 writer. 



The Woodbine, for example, is in part continuous with 

 the Bingen sand of Arkansas which contains a flora, and 

 which represents all of the Upper Cretaceous in Arkansas 

 below the Exogyra ponderosa zone. The Woodbine ap- 

 pears to be the same age as the Tuscaloosa of Alabama 

 which also contains many "true Dakota" plants and 

 which I have advanced reasons for considering as in part 

 contemporaneous with the Eutaw formation — the eastern 

 correlative of the Eagle Ford and Benton. That there 

 is a comparable relationship in Texas between the Wood- 

 bine and Eagle Ford seems likely but has not yet been 

 demonstrated. 



There is a similar Dakota element in the floras of the 

 Raritan and Magothy formations, and in the Carolinas 

 the plant beds are a part of the Black Creek formation 

 which contains a considerable marine fauna, as does also 

 the Magothy formation in New Jersey. Invertebrate 

 paleontologists have been inclined to correlate any traces 

 of marine organisms in these beds, even in a formation as 

 old as the Raritan, with the Senonian of Europe, whereas 

 I have argued from the floral evidence that these beds 

 should be correlated with the Turonian. There is abso- 

 lutely no question but that they are all not only Upper 

 Cretaceous but post Comanchean. 



The floral evidence in all of these cases is overwhelm- 

 ingly in favor of considering these floras more closely re- 

 lated to their known successors than to their known 

 ancestors and this remains true despite the very consid- 

 erable dicotyledonous element in the Patapsco formation 

 of Maryland and Virginia, which I have correlated with 

 the Albian stage of Europe and with the Fuson forma- 

 tion of the western Black Hills region. 



Undoubtedly it is confusing to continue talking about a 

 Dakota flora that is a composite, but which it is difficult 

 from regarding as an entity implied by its having a name. 

 I have tried to avoid this in a measure by speaking of a 

 "true Dakota" flora, meaning thereby the equivalent of 

 that of the Woodbine formation of Texas, and those of 

 corresponding age elsewhere, as opposed to such floras as 

 that found in the Cheyenne sandstone and at other local- 

 ities throughout the West that have mistakingly been 

 thought to come from the Dakota sandstone. 



