3914.] SOUTHEASTERN NORTH AMERICA. 147 



Since the early Eocene floras of Europe are so much like those 

 of southeastern North America an enumeration of the Sheppey 

 palms is of considerable interest. They include the genera Nipa, 

 (Enocarpns, Areca, Iriartca, Liz'tstonia, Sabal, Chamcerops, Thrinax, 

 Bactris, Asterocaryiun, and Elects. Of these Nipa and Sabal are rep- 

 resented in the Wilcox flora while Thrinax and Bactrites are present 

 in the embayment area in the Middle Eocene (Claiborne). The 

 Order Palmales, or more properly Arecales, has a single existing 

 family the Arecarese (Palm?e) with about 150 genera and consider- 

 ably over a thousand existing species about equally divided between 

 the oriental and occidental tropics. There are no temperate outliers, 

 although some species extend for considerable distances into the 

 temperate zone as for example Sabal adansonii which ranges north- 

 ward along the Atlantic Coast as far as North Carolina. The pres- 

 ent distribution of the palms is a good illustration of modern con- 

 tinental floral diversities succeeding a Tertiary cosmopolitanism of 

 floras and it shows further the part played by isolation in evolution, 

 also indicated by the abundance of monotypic genera in the Orient 

 where the tropical area is so much broken. Not a single species or 

 genus is common to the two hemispheres and even the tribes are 

 almost all either oriental or occidental. 



Regarding the origin of the palms most students regard the Pan- 

 danacese (screw pines) as their probable ancestral stock and while 

 the latter family is entirely oriental at the present time this was not 

 true in the Tertiary, and it is perhaps significant that the existing 

 genus Phytelephas which is regarded as intermediate between the 

 Pandanaceje and the Arecace?e is exclusively American, and that 

 genera now exclusively oriental like Nipa and Phoenix are repre- 

 sented in the American Tertiary (Nipa in the Wilcox and Phwnix in 

 the Vicksburg). There is no warrant for asserting that palms are 

 of occidental origin, at the same time their oriental origin is equally 

 difficult of proof and what we know of their geologic history conclu- 

 sively shows the inadequacy of the existing distribution in a discus- 

 sion of their phylogeny. 



The three Wilcox species of palms comprise a fan palm and two 

 feather palms. The Chamcedorea leaves represent a small palm 

 whose numerous modern allies are confined to America, being richest 



