PROCKKDINGS 



OF THE 



CALIFORNIA ACADEMY OF SCIENCES 



Fourth Series. 



Vol. IV, pp. 113-128, pis. 11-12. December 30, 1914. 



The Fauna of the Siphonalia sutterensis Zone 

 in the Roseburg Quadrangle, Oregon 



BY 



ROY E. DICKERSON 



Department oe Invertebrate Paleontology. 



Introduction. 



A definite connecting link between the Tejon group of Ore- 

 gon and that of California appears to be present in the upper- 

 most portion of the Umpqua formation on the Umpqua River 

 near the mouth of Little River. The fauna upon which this 

 correlation is based was obtained by Mr. Bruce Martin, until 

 recently Assistant Curator of Paleontology of the California 

 Academy of Sciences. 



The Siphonalia sutterensis Zone of California is found typi- 

 cally at the Marysville Buttes.^ Other localities where it has 

 been recognized also are at Oroville^ beneath the Older Basalt 

 of Oroville, South Table Mountain, and near lone^ Amador 

 County, California, and near Merced Falls, Merced County, 

 California. 



In all of these localities this zone of the Tejon group is the 

 only one present, the lower portion of the Tejon being absent. 

 The beds at the Marysville Buttes containing the Siphonalia 

 sutterensis fauna rest directly upon rocks of Chico-Cretaceous 



1 Dickerson, R. E., Fauna of the Eocene at Marysville Buttes, California, Univ. 

 Calif. Publ.. Bull. Dept. Geol., vol. 7, pp. 257-298, 1913. 



2 Dickerson, R. E., Note on the Faunal Zones of the Tejon group, Univ. Calif. Publ., 

 Bull. Dept. Geol.. vol. 8, pp. 17-25, 1914. 



3 Dickerson, R. E., The lone Formation of the Sierra Nevada Foothills, A Local 

 Facies of the Upper Tejon-Eocene, Science, New Series, vol. 40, pp. 67-70', 1914. 



