RANGE OF THE AUCELLA 



369 



Oregon. California. 



Umpqua Tejon Eocene. 



Chico Chico Upper Cretaceous. 



Aucella crassicoUis.. 



Aucella piochi.. 



"Myrtle." 



" Myrtle." 



.incellri errini/toni ■ 



Dothan. 



Galioe. 



Paleozoic. 



Shasta flora. 



!-. Jurassic flora. 

 1 f 



Correlalion ] 

 not fully < 

 established 



J J 









Horsetown. 









C8 



Lower Cretaceous. 



Knoxville. 







Franciscan. 





(■') 



Jurassic. 



Mariposa (re- 

 garded=lMonte 

 de Ore.) 





Paleozoic. 



HISTORICAL DEVELOPMENT 



The discovery of fossil plants by Aurelius Todd in Douglas county, 

 Oregon, more than thirty years ago has led finally, through the collections 

 of Will Q. Brown and the much larger collections of thd U. S. Geological 

 Survey, to an extensive study of the fossil flora of that region. Pro- 

 fessors Lester P. Ward and William M. Fontaine have been the chief 

 investigators, and their results appear in the Twentieth Annual Eeport 

 (part ii, pages 368-377) and Monograph XL VIII of the U. S. Geological 

 Survey. They regard the flora as Jurassic and studied it from tliree 

 localities in Oregon : one in the neighborhood of Buck mountain, extend- 

 ing north across Thompson branch of Olalla creek in Douglas county; 

 another in the same county, near Nichols station, on Cow creek; and a 

 third, the most important, on the forks of Ellc river, in Curry county, 

 Ijeside a very important locality near Oroville, California, at the western 

 foot of the Sierra Nevada. 



Since the investigations of Ward and Fontaine were published my 

 field party of the Geological Survey has mapped and somewhat extended 

 the localities in Oregon and discovered a number of new localities of 

 plant beds containing the same flora in the Klamath mountains of Trin- 

 ity county, California, especially at Big Bar and Eattlesuake creek. 



