628 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 54. 



Permian, although locally traces of the Lower Cretaceous may be 

 intercalated. 



According to our present knowledge of the genesis of the conti- 

 nental Tertiary deposits it can not be expected that similarity of 

 lithologic composition has any definite bearing upon correlation, 

 and it must be understood that the conclusions of the present paper 

 refer only to the fossiliferous outcrop which is discussed. 



The florule collected from this outcrop represents but six deter- 

 minable species, of which four are new, and three additional forms 

 that are generically but not specifically recognizable. It includes two 

 grass or sedge-like plants which are fragmentary and of no botanical 

 value beyond indicating the presence of such plants in this region at 

 that time. Willow leaves are present, but not specifically deter- 

 minable. The most abundant forms are the Platanus and the Sap- 

 indus. The Gymnocladus^ Rhamnus, Bumelia^ and Diospyros are 

 all represented by a scanty amount of material, but as the collection 

 is a small one the individual abundance of the different species is 

 probably without significance. 



All of the forms appear to have been alluvial species of river bot- 

 toms, and most of them have their genera still represented in the 

 valleys of the principal streams that enter eastern Oklahoma from 

 the Coastal Plain of the Gulf States. This statement is true of Plata- 

 nus, Gymnocladus, Sapindus, Rhamnus, Bum,elia, and Diospyros. 

 All these genera are normal constituents of the rich alluvial de- 

 ciduous forests of the southeastern United States, and the presence 

 of fossil representatives in western Oklahoma shows that climatic 

 conditions in that region were more mesophytic toward the close of 

 the Miocene than they are at the present time, with the stream valleys 

 covered with a mixed deciduous forest, which may also have covered 

 more or less of the interstream areas. 



Regarding the age indicated by this florule, it may be said that 

 the Cyperacites, Oaulinites, and Salix are without significance. Only 

 one of the nine forms — namely, Rhamnus lesquereuxi — is limited to a 

 single outside horizon, and this species occurs in the late Miocene of 

 Florissant, Colorado. Platanus aceroides and Diospyros hracliysepala 

 are recorded throughout the Tertiary in both this country and 

 Europe, and while both are probably composite species, it is impos- 

 sible to segregate them in the present state of knowledge. Both are, 

 however, typically Miocene forms, the Platanus being found in the 

 John Day Basin on the west coast and in the Calvert Miocene of the 

 Atlantic coast, and indistinguishable leaves of the Diospyros occur 

 at Florissant, Colorado. Moreover, the new species of Sapindus ap- 

 proaches closely to Sapindus lancifolius Lesquereux, another Floris- 



