PHYSICAL CONDITIONS AND AGE INDICATED BY FLORA OF ALUM BLUFF FOBMATIOX. 



53 



this species to a few representative citations.' 

 Tlie species has been recorded by Lesquereux, 

 Ward, and others from tlie lower Eocene of 

 the Rocky Mountain area, as well as by 

 Heer from West Greenland. I am not cer- 

 tain that all these records are correct, for 

 Diospyros hrachi/sepala is typicallj- an OUgo- 

 cene-XIiocene form. It is found in the type 

 area in both the Aquitanian and Burdigahan. 

 The jVlum Bluff leaves, like most of the 

 material referred to this species, are relatively 

 small, about 5.5 centimeters in length and 2.8 

 centimeters in maximum width, midway be- 

 tween the apex and the base, which are about 

 equally pointed, the general outhne being al- 



1 A much more complete sj-nonymy is given in my paper The lower 

 Eocene floras of southeastern North America: t.". S. Geol. Suney Prof. 

 Paper 91 (in press). 



most eUipticiJ. The midrib is stout and the 

 secondaries tliin, numbering six or seven sub- 

 opposite to alternate camptodrome pairs. The 

 leaves here described are close to a number of 

 examples figured by Heer from the type local- 

 ity, but are relatively slightly broader than 

 some of the forms referred to this species by 

 different authors. In some respects they are 

 very similar to Diospyros lamarrnsis Knowl- 

 ton,- from Lamar (probabh' upper Miocene), 

 in Yellowstone Park. 



OccmTonce: ^Uuiii Bluli formation, .Vlum 

 Bluff, Liberty County, Fla. (collected by E. W. 

 Berry). 



Collection: United States National Museum. 



« Knowlton, F. H., U. S. Geol. Surrey Mon. 32, pt. 2, p. 751, pi. 95, 

 figs. 5, 6; pi. 96, fig. 4, 1899. 



