Vol. VI] WEAVER— EOCENE OF LOWER COWLITZ VALLEY 3 



and one-half miles east of the town of Vader in Lewis County. 

 Many new species of mollusks were described and the fauna as a 

 whole was referred to the Cowlitz formation which was re- 

 garded as of Eocene age and possibly older than the Tejon. A 

 suggestion was, however, made that future studies might show 

 that it was identical with the Tejon. 



A further discussion of this region is to be found in a report 

 by Arnold and Hannibal* on "The Marine Tertiary Strati- 

 graphy of the North Pacific Coast of America." In 

 this paper the Tejon is divided into three formations : the Che- 

 halis, Olequah and Arago formations. They are referred to 

 as the Tejon Series. The Chehalis and Olequah formations 

 are present in the region involved in this report. The Arago 

 is absent. On the basis of fossil floras colder climatic condi- 

 tions obtained during the deposition of the Chehalis formation 

 than during that of the Olequah. 



During the last year an important paper appeared by Dr. 

 Roy E. Dickerson^ entitled the "Fauna of the Type Tejon : Its 

 Relation to the Cowlitz Phase of the Tejon Group of Washing- 

 ton." Collections were made and studied from certain locali- 

 ties along the Cowlitz River and a number of new species were 

 described. A total of 95 species are listed from Washington 

 and 55 of these are found within the Tejon of California. The 

 paper gives the results of studies at the type Tejon locality 

 in southern California and makes correlations with the Cowlitz 

 phase of the Tejon in Washington. He states "The Cowlitz 

 phase of the Tejon of Washington appears to represent the 

 same faunal facies as the fauna of the type Tejon, i. e., the 

 Rimella simplex zone is present in both localities." 



GEOGRAPHY OF AREA UNDER INVESTIGATION 



The region mvolved in this study is situated in southern 

 Lewis County and extends from the town of Winlock southerly 

 for a distance of fifteen miles to the town of Castle Rock. From 

 east to west the area averages five miles in width. Just east 



^Arnold, Ralph, and Hannibal, Harold, The Marine Tertiary Stratigraphy of the 

 North Pacific Coast of America, Proc. Am. Phil. Soc, vol. 52, pp. 566-571, 1913. 



'Dickerson, R. E., "Fauna of the Type Tejon: Its Relation to the Cowlitz Phase 

 of the Tejon Group of Washington," Cal. Acad. Sci. Proc, 4th series, vol. 5, pp. 

 35-51, 1915. 



