136 BERRY— LOWER EOCENE FLORA OF [April 25, 



was far richer than floras of small insular areas of the American 

 tropics of the present, as for example, that of the Bahamas which are 

 relatively close to mainland, where in addition to difficulties of intro- 

 duction there is relatively great uniformity of edaphic factors and 

 directly adverse factors such as winds, which limit the floral display. 



Without pursuing the subject in greater detail it may be assumed 

 to be proven that the Wilcox flora is a typical coastal flora. Com- 

 pared with recent coastal floras it is at once apparent that its affin- 

 ities are entirely with those of tropical and subtropical America. It 

 has much in common with the Bahaman flora and that of the Florida 

 keys, but is far richer in arborescent forms. Comparisons with the 

 larger islands of the West Indies show more elements in common, 

 such differences as are apparent being due to the prevalence of por- 

 ous coral rock along these recent shores while the Wilcox shores were 

 not of this character. The most complete agreement is furnished by 

 the floras along the Caribbean coast from Central America to north- 

 ern Brazil. A considerable number of genera found in the Wilcox 

 flora do not range through the West Indies at the present time and 

 the explanation seems to be that the Wilcox flora more closely re- 

 sembles the original flora of the whole American equatorial region 

 which became restricted during the epeirogenetic and climatic changes 

 of the INIiocene or Pleistocene and the elements now lacking in the 

 West Indies never regained all of the area of distribution lost at that 

 time. 



It may seem improper to say that a flora with abundant forms 

 of Artocarpus, Nipa, Cinnaniomum, Banksia, etc., is entirely Amer- 

 ican in character but if the brief sketches in the botanical discussion 

 which follows are read it will be obvious that these genera, oriental 

 in the existing flora, were cosmopolitan in the early Tertiary, so that 

 it would be entirely misleading to draw conclusions from existing dis- 

 tribution alone. 



The Wilcox waters of the upper embayment were always shal- 

 low ; there were fringing bars and lagoons as well as deltas, estuaries 

 and swampy bayous. The deposits in places show river action and 

 streams shifting about over sand flats. Regarding actual tempera- 

 tures so little is known after all of the relations of modern plants to 

 their climatic environment that results can only be qualitative and 

 not quantitative. 



