F. H. Knowlton — Jurassic Flora of Oregon. 41 



have never been found commingled, but the fauna is occasion- 

 ally, as at Elk River, also found interbedded with, as well as 

 below, the J urassic flora, showing that it has a greater vertical 

 range than has usually been accorded to it. 



2. Western Side of the Sacramento Valley in Shasta and Tehama 

 Counties, Calif orida. 



This is much the largest and most important of the areas 

 which have afforded the Lower Cretaceous flora. It is found 

 at many localities on the North fork of Cottonwood Creek 

 near the town of Ono, Shasta County, and along the Cold fork 

 and South fork of Cottonwood Creek, as well as near the Post 

 Oflice of Lowrey and as far south as Paskenta, all in Tehama 

 County. The field relations of this region have been so fully 

 set forth by Professor Ward* and Mr. Diller that it is unnec- 

 essary again to go over the matter. 



This area is also notable as that which has supplied the 

 major portion of the Knoxville fauna, and since small por- 

 tions of this fauna were found in association with the Jurassic 

 flora at Elk Eiver, Big Bar, etc., it was assumed by some that 

 the flora of the western side of the Sacramento Valley would 

 present the same associations-that is, prove to be a Jurassic 

 flora-but it very distinctly is not. By combining the floras 

 collected by Professor Ward and studied by Professor Fon- 

 taine, with those collected by James Storrs for Mr. Diller and 

 reported on by the writer, we have the following aggregate 

 list of 59 forms, only a single species of which is common to 

 the Jurassic flora. It is distinctly a Lower Cretaceous (Neo- 

 comian) flora and flnds its closest affinity with the Kootenai of 

 the interior region, the Trinity of Texas, and the lower Poto- 

 mac of the Atlantic Coastal Plain. A further analysis and 

 comparison will be made in later pages. 



List of Loioer Cretaceous Flora of the Western Side of the 

 Sacramento Valley. 



DicJcsonia pachyphylla Font. 

 Thyrsopteris rarinervis Font. 

 Cladophlebis parva Font. 



" Browniana (Dunk.) Sew. 



" falcata Font. 



" heterophylla Font. 



" TIngeri (Dunk.) Ward. 



" ala'taf Font. 



Matonidium Althausii (Dunk.) Ward. 

 Gleichenia JSTordenskioldi Heer. 



" f Gilbert- Thompsoni Font. 

 * U. S. Geol. Siirv. Mon. 48, p. 211 et seq., 1905. 



