60 Berry — Ni/pa-palm in the North American Eocene. 



nmbilicate apex, and range from 5 cm to 8 cm in length and from 

 3 cm to 5 cm in maximum width. The surface is more or less 

 fibrous and obscurely angled. 



The discovery of Nipadites in the Eocene of Mississippi 

 serves to fix more definitely the age of the Wilcox Group in 

 terms of European chronology. It also emphasizes the lagoon 

 and estuarine character of the Wilcox deposits of the upper 

 Mississippi Gulf and the sub-tropical character of the strand 

 flora that flourished along the margin of the low-lying conti- 

 nental lands that bordered the Gulf. It also raises an interest- 

 ing question regarding the path of migration of Nipadites. 

 Since these fruits appear to be found in older deposits abroad 

 the genus is very likely of oriental origiu. It could have 

 reached the Western Hemisphere by two routes. The fruits 

 may have floated across the Atlantic, which would hardly be 

 possible if the Atlantic currents of the Eocene were at all sim- 

 ilar to those of the present time. If there was more or less of 

 an Atlantic equatorial land-mass, as a number of geologists 

 have advocated, the foregoing migration would have been a 

 simple matter. On the other hand, and this seems to me to be 

 the more probable hypothesis, the range of these palms may 

 have covered a large part of Oceanica during the late Creta- 

 ceous and early Eocene, and they may have been carried by 

 ocean currents across the submerged lands of what is now 

 Central America and into the Eocene Mississippi Gulf. The 

 accompanying sketch-map (fig. 1) shows in a generalized but 

 graphic way the range of the existing .Nipa and the early 

 Tertiary occurrences of Nipadites. 



Johns Hopkins University, Baltimore. 



