23G BERRY— LOWER EOCENE FLORA OF [ApHi 25, 



corollas and other special features. This theorem is corroborated 

 by the in general modernness of the alliance. 



Six of the Gamopetalous orders are represented in the Wilcox 

 flora. The first of these, the Primulales, in its fullest development in 

 existing floras includes the three families Myrsinacese, Primulacese 

 and Plumbaginaceje. They are structurally much alike with a single 

 cycle of stamens opposite the petals, and a unilocular ovary with a 

 free central placenta. This community of floral organization can 

 only be attributed to convergence and not to filiation since the Myr- 

 sinacese are old forms which in modern floras are predominantly 

 tropical and American while the Primulacese are chiefly north tem- 

 perate and boreal herbs of relatively recent evolution : and the Plum- 

 baginace?e are very modern halophytic herbs and undershrubs of 

 salt beaches and steppes, the majority being found in the Alediter- 

 ranean and Caspian regions. 



The Myrsinacese, the only family represented in the Wilcox flora, 

 is characterized by alternate, simple, coriaceous, punctate, exstipulate 

 leaves ; perfect, regular flowers ; and single seeded drupaceous fruits. 



The family contains about thirty genera and 530 species of shrubs 

 or trees, largely tropical and predominantly American. Thus eleven 

 genera containing upward of 200 species are peculiar to America 

 while there are only four genera with less than a dozen species 

 peculiar to Asia, and three genera with about 100 species peculiar 

 to Africa. 



The genus Myrsine Linne is found on all the continents except 

 Europe and in Polynesia. Its distribution is extratropical in the 

 African region. Euardisia Pax is found in all tropics. Maesa For- 

 skal is found in all oriental tropical countries as is also the monotypic 

 genus Mgiceras Gsertner, a member of the coastal mangrove associa- 

 tion. The genus Cybianthiis Martins, largely South American, has 

 species in the Philippines and in New Grenada. There is little that 

 is significant in the recent distribution of the family and the fossil 

 record is very incomplete. 



Over seventy-five fossil forms have been referred to Myrs'mc. 

 The oldest are the seven or eight forms recorded from the Upper 

 Cretaceous. All of the older of these (Cenomanian) are from North 

 America and only one from the Turonian of Bohemia occurs in the 



