176 BERRY— LOWER EOCENE FLORA OF [April 25, 



the genus GleditsiophyUiim, a form-genus proposed by me in the first 

 instance for an Upper Cretaceous form from North CaroHna. 

 There is a certain unavoidable duphcation in the giving of specific 

 names to unattached pods and leaflets since in some cases they may 

 belong to the same botanical species. I have followed this method, 

 however, in all instances where I was not sure of such a relationship. 

 The Mimosacese of the Wilcox are referred to four genera. 

 The genus Acacia represented by a single indisputable species in 

 which the leaves are reduced to phyllodes is of great interest since 

 in the existing flora the 450 species are largely confined to the Aus- 

 tralian region. The section Phyllodineae to which the Wilcox species 

 is referred has about 300 existing species which are confined to Aus- 

 tralia and Oceanica although in Eocene times they were also present 

 in Europe. It is a curious commentary on the modern character of 

 the earlier Tertiary floras that the reduction of foliar organs and the 

 habit of phyllody, often correlated with modern arid conditions, 

 should have really been developed in these early floras. 



The genus Inga, represented in the Wilcox by four well marked 

 species, has upwards of 150 species in the existing flora, all of which 

 are confined to the American tropical and subtropical regions. Its 

 geological history is for the most part unknown although it appears 

 to be represented in American Upper Cretaceous floras by Inga cre- 

 tacea Lesquereux which occurs in the Dakota Sandstone and in the 

 Tuscaloosa formation of Alabama. Ettingshausen has described a 

 species from the Cenomanian of Saxony {Inga Cottai) and the 

 European Miocene has furnished two or three species, while Engel- 

 hardt has described a Tertiary species from Bolivia. 



In the genus Pithecolohhim, which has two Wilcox species and 

 belongs to the same tribe as Inga (Ingese), while the majority of the 

 100 or more existing species are American there are over a score in 

 tropical Asia and a few in tropical Australia and Africa. With the 

 exception of a Tertiary species from Bolivia I do not know of other 

 fossil occurrences. 



The genus Mimosites, with four Wilcox species, represents trees 

 of the Mimosa type very abundant in recent species referred to sev- 

 eral genera which are either American, Asian, Australian or ^African, 



