R. W. 



Chaney — A Fossil Flora, 



Fraxinus ungeri{ f) 



Miocene 



Florissant, Colo. 



Laurus saliciformis 



Miocene 



Corral Hollow, Calif. 



Nelumhoi?) sp. 







Planer a my ricce folia 



Miocene 



Florissant, Colo. 



Populus crassa 



Miocene 



Florissant, Colo. 



Salix n. sp. 







Sapindus n. sp. 







Sterculea cf. engleri 



Miocene 



Florissant, Colo. 



91 



Zizyphus piper oides{1) Eocene Chalk Bluffs, Calif. 



The Miocene age of the flora is indicated by its relation 

 to the flora of the Florissant beds, with which it has eight 

 species (three doubtfully determined) in common, and to 

 the Miocene deposits of Corral Hollow, a total of nine 

 Miocene species. Two species (one of which is doubtfully 

 recorded) are found at Chalk Bluffs, California where the 

 deposits are commonly listed as of Miocene age, though 

 they will doubtless be found to be older, and are here 

 designated as of Eocene age. One of these, Aralia whit- 

 neyiy has been doubtfully recorded from the Miocene 

 of the John Day Basin in Oregon. The resemblance 

 noted of one of the species of Ficus to Ficus puryearensis 

 of the Wilcox is probably nothing more than superficial, 

 as indicated by several incomplete and poorly preserved 

 specimens in the Puente flora. The age of the flora may 

 be tentatively established as Miocene, which is in accord 

 with the indications of the faunas. 



With the exception of Ficus, Laurus, and Sapindus, 

 which occupy shores and coastal swamps, the genera 

 included in the flora are commonly found on stream 

 borders and in moist woods. Nelumbo, doubtfully deter- 

 mined, is a fresh-water aquatic form. Thus there is 

 evidence that most of the leaves have been transported 

 seaward, probably by streams, and mingled with marine 

 deposits along the shores. The coriaceous character of 

 the majority of the leaves would allow this mode of trans- 

 portation without their destruction. 



The climatic implications of the flora and its means of 

 transportation to the sea are not in accord with the conclu- 

 sions of Jordan and Gilbert.^ Describing the conditions 

 under which a relatively pure deposit of diatomaceous 

 shale would be accumulated, they state: — ^'The region 

 must have been arid, else sand would have been washed 

 in and mixed with the diatom deposits.'^ This assump- 



^ Jordan and Gilbert, op. cit. p. 13. 



