108 FOSSIL FLORA OF THE JOHN DAY BASIN, OREOON. [bull. 204. 



h/r((f<i^'/ii</l<(tin uregoNfiiiKi^ etc., that wore supposed to hiivc conic from 

 the Auriferous yravels, are in r(>ality contined to the Van Horn's 

 ranch locality. This correhition therefore fails, and the age of the 

 Van Horn's ranch material must be tixed in other ways. 



The tal)l(^ on the precedinu- page shows at a g'lance that the geologic 

 horizons of those species found outside these beds are decidedl}- higher 

 than those of either of the floras previously considered. Thus, 17 

 species out of 25 are found in the Miocene. The oldest beds repre- 

 sented, at least by species having any particular value for tixing the 

 age, is the Fort Union, which contains 5 or (> of the species listed. 

 Sequoia Lany.sdoriii extends throughout the entire Tertiary, and pos- 

 sibly even into the Upper Cretaceous. Phragrnites aoum/eniils extends 

 from the Laramie to the Pliocene, but it is at best a doubtful organ- 

 ism, hard to identify satisfactorily. Salix angusta is another species 

 ranging throughout the Tertiary, but it is simply a narrow-leaved 

 willow that may or may not be the same form at all points where it 

 has been reported. Seven of the species enumerated. 2 of which 

 are doubtful,. are found in the Green River beds, and (>, one of which 

 is open to question, have been found in the Eocene in general. Seven 

 species are found in the so-called Eocene of Alaska, which was, until 

 recently, regarded as of Lower Miocene age. 



If dependence were placed exclusively on the distril)ution of the 

 above-mentioned forms in fixing the age of these beds, the tendenc}^ 

 would be to regard them as not younger than Lower Miocene, or even 

 possibly as old as the Upper Eocene, but when we take into account 

 the affinities and relationships of the forty or more named species that 

 are confined to these beds, the preponderance of evidence would seem 

 to relegate them to an age as young as Upper Miocene. Thus the 

 species of Salix are closely allied to various living species, such as S. 

 m'gentea^ etc. The species of Quercus are distinctly modern. QueTcus 

 pseudo-lyrata is hardly to be Idistinguished from Q. lyrata; Q. Mer- 

 riami is also near Q. lyrata; Q. durkiscula is very close to Q. minor ^ 

 and Q. urstna to the living Q. nana. The form referred to Artocarpus 

 californica^ if correctly identified, is close to the living A. inclsa; 

 Hydrangea Bendirel is closely related to several living species; and 

 the species of Liquidambar are not far from Z. Styraciflua. The two 

 species referred to Prunus are close to the living P. demissa, P. vir- 

 giniana^ etc. The maples are very modern in appearance, being 

 related to A. saccharum., A. macrophyUmn., etc., and the box elder is 

 not far from the living species. The species described as jEscidm 

 simulata is similar to ^. odandra and y'E. glahra. 



Taking all lines of evidence into account, it seems warranted to 

 refer these beds to the Upper Miocene. 



