I9I3.] STRATIGRAPHY OF PACIFIC COAST OF AMERICA. 



581 



A typical San Lorenzo fauna has been collected from the area 

 north and east of Porter, Washington. 



Partial List of Species in the San Lorenzo Horizon of the Astoria Series 

 (Middle Oligocene) of the Porter-Oakville District, Washington. 



Note. — Thracia condoni Dall, Acila cordata Dall, dalli Arn. and shumardi 

 Dall, Strepsidura calif ornica Arn. {S. oregonensis Dall), Epitonium condoni 

 Dall and rugiferum Dall, and Miopleionia indurata Conr. are also character- 

 istic species of this horizon. 



Locality 50; massive shaly sandstone, road cuts one fourth of a mile 

 southeast of Porter along Chehalis River, Washington. (H. Hannibal.) 



28 Species characteristic of this horizon. 

 30 Species still living. 



