406 DILLER 



Pofiulus zaddachi Heer. 



Aralia angustiloba ? Lesq. 



Juglans califomica P Lesq. 



Ulmus califomica Lesq. 



Ficus tilicBfolia ? Al Branner. 



Among the shells found with or very near the fossil leaves, 

 Dr. Wm. H. Dall has recognized over 20 genera, and remarks : 

 "The fossils are Eocene. They contain a number of inter- 

 esting things, particularly the Orbitolites, which is usually char- 

 acteristic of the Oligocene on the Atlantic coast and is now for 

 the first time recognized from the Pacific coast." 



The fossil leaves were found near the southeast border of the 

 Eocene where shells are not abundant, but a short distance far- 

 ther northeast they become very abundant locally with such 

 characteristic forms as Venericardia planicosta and Turritella 

 nvasana, and there is no doubt concerning the Eocene age of 

 the strata containing the fossil leaves. 



Of the 10 species of plants identified seven are somewhat in 

 doubt, but three, Magnolia lanceolata, Aralia zvhitneyi, and 

 Populus zaddachi, are completely satisfactory. They all occur 

 in the auriferous gravels of Independence Hill, on the western 

 slope of the Sierra Nevada, as well as on the summit of the 

 northern end of the range, 7^ miles southwest of Susanville. 

 The last species occurs at many other localities among which 

 may be mentioned the lone formation of Kosk Creek and Little 

 Cow Creek of Shasta County, Cal., and the auriferous gravels 

 of Moonlight, Chalk Bluff, and Volcanic Hill. 



Eight of the 10 species reported from the Eocene of Oregon, 

 occur, according to Mr. Lindgren, in the "bench gravels" of 

 Independence Hill, in California. It seems probable therefore 

 that not only the " deep gravels " but also the " bench gravels," 

 both of which belong to the pre-volcanic gravels, may be of 

 Eocene age. 



