172 BERRY— LOWER EOCENE FLORA OF [April 25, 



The order Resales includes about eighteen famihes-^ with over 

 fourteen thousand existing species, the largest families being those 

 of the Leguminosae, and the Rosacea, Saxifragace^e and Crassulacese. 

 Some members of the alliance are close to the Ranales in their apo- 

 carpy, hypogyny and the indefinite repetition of certain floral mem- 

 bers, and the order culminates in the relatively modern Papilionacese. 

 Five families of Rosales are present in the Wilcox flora. Of these 

 the three leguminous families are by far the most abundant. 



The family Hamamelidacese consists of about nineteen genera 

 and fifty species. Twelve of the genera are confined to the Asiatic 

 region. One genus is doubtfully confined to Australia : Three gen- 

 era are African : and three genera are common to Asia and eastern 

 North America. The family is remarkable in containing no less 

 than nine monotypic genera. A consideration of the existing dis- 

 tribution is not only of exceeding interest but also conclusive proof 

 of an extended geologic history, which unfortunately has not yet 

 been unravelled. Since the group is scarcely if at all represented in 

 the existing flora of Australia or in its fossil flora, its present range 

 over Asia would seem to have been accomplished after the land con- 

 nection with Australia had been interrupted. As the only known 

 Cretaceous fossil forms are from North America there is a prob- 

 ability that the group had its origin in the North American region. 

 The fossil species are not numerous enough, however, for definite 

 conclusions on this point. 



The genus HarnaincUs and its generalized fossil type Hamamc- 

 litcs Saporta have five species in the Dakota sandstone, one of which 

 occurs in the Atlantic coast Upper Cretaceous (Middendorf beds of 

 South Carolina) and another is doubtfully represented in the sup- 

 posed Upper Cretaceous of Argentina (Kurtz). There are two 

 Paleocene species in France and Belgium, and Conwentz has de- 

 scribed characteristic flowers preserved in perfection in the Baltic 

 Amber (Sannoisian) as Hamamclidanthium. 



The genus Parrotia, with a single existing species of northern 

 Persia and the Caucasus, has three species in the Dakota sandstone : 



^'^ The family Platanacese, which by the majority of students is referred 

 to the Rosales, I regard as the sole survivor of an independent order, the 

 Platanales, closely related to the Urticales. 



