19I4-] SOUTHEASTERN NORTH AMERICA. 153 



than in the European Tertiary, although it was present in the em- 

 bayment area in the late Upper Cretaceous (Ripley formation of 

 Tennessee). Its meager representation in the Wilcox time may be 

 due to the more tropical climate conditions. The modern Myricas 

 are temperate and subtropical and a number of the species are coastal 

 forms of either swamps or sand dunes. Myrica clccanoides was evi- 

 dently a coastal form and so was Myrica wilcoxcnsis. The latter is 

 very similar to the existing Myrica cerifera which ranges from New 

 Jersey to Texas and is also found on the Bermudas and Bahamas. It 

 is most abundant and vigorous in the sandy swamps along the south 

 Atlantic and Gulf coasts and its habitat may be compared with that 

 of Myrica zcilcoxcnsis. The latter seems to be the ancestral stock of 

 a very similar species which occurs along the Middle Eocene (Clai- 

 borne) coast of the embayment. 



The order Fagales, which includes such important timber trees 

 of the temperate zone, is comprised by the two families Betulaceae 

 and Fagaceae, together containing about 450 existing species, of 

 which three fourths belong to the Fagaceae. Only the latter family 

 is represented in the Wilcox although the Betulaceas are character- 

 istically developed in the Upper Cretaceous of North America. 



The family is unrepresented in the Wilcox flora probably because 

 the climate was too warm and this reason may also account for the 

 absence of true oaks since the Fagaceae are represented in the Wil- 

 cox flora by only the genus DryophyUum with four rather wide- 

 spread and often common species. 



The genus Dryophyllum is of worldwide distribution and consist- 

 ently uniform characters in the various horizons of the late Cre- 

 taceous and early Eocene from the Senonian to the Ypresian stages. 

 It especially characterizes the dawn of the Eocene and represents the 

 ancestral stock from which the genera Castanea, Castanopsis, Pasania 

 and Quercus took their origin, although this origin was in the late 

 Cretaceous. As might be expected Dryophyllum has long since be- 

 come extinct. The Wilcox species were apparently strand types as 

 were also the numerous species enumerated by Debey, the describer 

 of the genus, from the sandy shores of the Upper Cretaceous sea of 

 Rhenish Prussia. Dryophyllum is abundant in the Montian of Bel- 

 gium and in the littoral sands of Ostricourt and Belleu in 



