1916] 



Dickerson: Tejon Eocene of California 409 



692. Marysville Quadrangle. Tejon Group. Two and one-eighth miles 

 east, ten degrees south of South Butte. Coll., C. K. Studley. 



2225. Chico Quadrangle. Tejon Group. Two miles north of Oroville 

 in the Dyer mining shaft. Colls., J. Ruckman and R. E. Dickerson. 



2365. Jackson Quadrangle. Tejon Group. Red sandstone quarry three 

 miles southeast of Buena Vista. Coll., R. E. Dickerson. 



2067. Sonora Quadrangle. Tejon Group. One mile south of Merced 

 Falls on top of a low hill, "Planicosta Butte". Coll., R. E. Dickerson. 



Of the species listed the following have not been reported at lower 

 horizons in California : 



Trochocyathus( ?) perrini, Barbatia, sp. a., Cardium marysvil- 

 lensis(f), Glycimeris marysvillensis, Venericardia planicosta mer- 

 riami, Architectonica weaveri, Bittium longissimum, Caricella storm- 

 siana, Cordiera gracillima, Call lost oma( ?) arnoldi, Galeodea 

 sutterensis, n. sp., Fusinus lineatus, Olivula ■marysvillensis, Chryso- 

 domus martini, Surcula crenatospira, Surcula holwayi, Surcula 

 davisiana, Siphonalia sutterensis, Terebra ivattsiana, Voluta lawsoni, 

 Bittium feather ensis, n. sp., Cerithiopsis orovillensis, n. sp., Drillia 

 cooperi, Drillia orovillensis, Nyctilochus thunani, n. sp., Murex nashi, 

 n. sp. 



A study of a littoral facies of the Siphonalia sutterensis fauna at 

 Oroville, at locality 692, and at the mouth of Little River, North 

 Fork of the Umpqua River in beds near the top of the Tejon group 

 (Umpqua Formation), confirms and reinforces the writer's previous 

 conclusion that "The unique character of the Marysville Buttes 

 fauna appears to be due to its representing a period from which no 

 adequate fauna had previously been obtained. . . . That it evolved 

 from the typical Tejon there can be little doubt. ... In other words, 

 the evidence indicates that the Marysville Buttes fauna represents 

 a later zone or stage of the Eocene than the typical Tejon." The 

 faunal list given above demonstrates conclusively that the Siphonalia 

 sutterensis fauna was evolved from the typical Tejon and that the 

 fauna is in reality much closer to the Tejon than the writer sus- 

 pected three years ago. On this account the fauna is placed as the 

 uppermost zone of the Tejon group in California. 



CORRELATION OP THE IONE AND THE AURIFEROUS GRAVELS 



Various workers in Sierran geology, including Whitney, Tur- 

 ner, Diller, and Lindgren, have recognized a genetic relationship 

 between the auriferous gravels and the lone formation. Diller 37 says 



07 Diller, J. S., Topographic Revolution on the Pacific Coast, Fourteenth 

 Annual Report, U. S. Geological Survey, Part II, p. 420, 1894. 



