28 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



Blakeley horizon — Acila gettysburgensis zone Oligocene 



Porter horizon — Turritella porterensis zone OHgocene 



Lincohi horizon — Molopophorus Hncohiensis zone .. OHgocene 

 Tejon group Eocene 



MOLOPOPHORUS LINCOLNENSIS ZONE 



The oldest post-Tcjon fauna which has been recognized 

 within western Washington occurs in sandy shales outcrop- 

 ping along the south bank of Chehalis River five to 10 miles 

 west of the city of Centralia, in Thurston County. Fossils in 

 this locality are fairly abundant and in an excellent state of 

 preservation. An examination of the faunal lists from this 

 region indicates that several of the species are identical with 

 those occurring in the underlying Tejon Eocene. Among 

 these are Brachysphingus clarki Weaver, Leda uvasana Dick- 

 erson, Crassatellites washingtoniana Weaver, Exilia dicker- 

 soni Weaver, Hemifusus ivashingtonianus Weaver, and Strep- 

 sidura oregonensis Dall, 



The following species have been recognized as occurring 

 in the rock blufifs along the south bank of Chehalis River west 

 of Lincoln Creek. The strata containing the fauna may be 

 referred to as the Lincoln horizon** and the fauna itself as the 

 Molopophorus lincolnensis zone. 



Pelecypoda Nucida washingtonensis 



Cardium lincolnensis Weaver Weaver 



Cardium lorenzanum ( Arnold ) Ostraea lincolnensis Weaver 



Crassatellites washingtoniana ^olcn ciirtus Conrad 



Weaver Solen parallelus Gabb 



Crassatellites cowlitsensis Pitaria dalli Weaver 



Weaver 

 Crenella porterensis Weaver 



Leda uvasana Dickerson Dentalium straminetim Gabb 

 Leda lincolnensis Weaver 



Macrocallista pittsburgensis Brachiopoda 



Dall Terebr alalia, sp. 



'The use of the term Horizon is in the sense of a deposit formed at a particular 

 time and identified by distinctive fossils. 



SCAPHAPODA 



