226 BERRY— LOWER EOCENE FLORA OF [April 25, 



reverse of the hypothesis proposed by Deane (op. cit.) but one that 

 accords far better with the facts not only of geologic history, but 

 with those of existing distribution. 



As is pointed out in the systematic part of this work all of the 

 Wilcox forms are coastal types closely related to existing American 

 species of similar habitat. About 150 fossil forms have been re- 

 ferred to the Myrtacese, one third at least having been described as 

 species of Eucalyptus. At least half of these occur in the Cretaceous 

 of all parts of the world, but particularly throughout the northern 

 hemisphere. They are especially well represented in North Amer- 

 ica and the possibility that they are ancestral forms of Myrcia or 

 Eugenia has already been pointed out. A similar widespread distri- 

 bution but less specific variation characterizes the Eocene forms that 

 have been referred to Eucalyptus. The Oligocene records are all 

 European and the Miocene records include both Europe and Asia. 



The genus Myrtus has about 24 fossil species, all European, the 

 majority being almost equally divided between the Oligocene and the 

 Miocene. The oldest forms are early Eocene but the form-genus 

 Myrtophyllum Heer has several Upper Cretaceous species in Eu- 

 rope, America and Australia, as well as Tertiary species in Europe, 

 Asia and South America. 



The genus Myrcia DC. so well represented in the Wilcox flora 

 has species in the European Oligocene, four species in the early Ter- 

 tiary of Chili and one in the Pliocene of Brazil. 



The genus Eugenia, also prominent in the Wilcox flora, has its 

 oldest known species in the Dakota sandstone. It is represented in 

 Europe throughout the Tertiary from the lower Eocene to the 

 Pliocene. 



The genus Callistcmon R. Brown has been identified in both the 

 Upper Cretaceous and Tertiary of Europe and no less than 25 spe- 

 cies have been referred to the genus Callistemophyllum Ettings- 

 hausen. These include Upper Cretaceous forms in America and 

 Europe, Eocene forms in Greenland and Australia, and numerous 

 Oligocene and Miocene species in Europe. 



Leptospermun\j Leptospermites and Leptospermocarpum havebeen 

 identified from the Upper Cretaceous and Tertiary of Europe: Tris- 



