144 



University of California. 



[Vol. i. 



color, often argillaceous and passing into sandy shales. Interbedded 

 with these are frequent hard, well-cemented shell beds, and hard 

 beds of pebbly conglomerate. Shell beds also occur in a soft con- 

 dition both sandy and clayey. There are besides these occasional 

 thin lignitic seams, and toward the north end of the section there is 

 a thin bed of white volcanic ash. The stratification is usually very 

 clearly and sharply marked. 



Fossils. — The series abounds in Pliocene fossils both in this par- 

 ticular section and in other parts of the terrane. Dr. J. G. Cooper 

 lists the following species from this cliff section in his "Cataolgue of 

 Californian Fossils," 1888: — 



Area microdonta Conr. PI. 



*Chione succinta Val. PI. 



Crepidula grandis Midd. PI. 



Columbella Richthofeni Gabb PI. 



*Nassa fossata Gld. PI. 



*01ivella biplicata Sby. PI. 



*Purpura crispata Chem. Var. septentrionalis Rve. PI. 

 *Standella falcata Gld. PI. 

 *Echinarachnius excentricus Esch. PI. 

 Scutella interlineata Stimp. PI. 



The following additional forms have been collected by the writer, 

 and by him submitted to Dr. W. H. Dall, who has kinder identified 

 them: — 



*Nassa mendica Gld. 



*Macoma (like sabulosa Spngl.) 



*Macoma nasuta Conr. 



*Chrysodomus lyratus Mart. 



*Monoceros engonatum Conr. 



*Astyris gausapata Gld. 



Crepidula praerupta. 



*Schizothserus Nuttallii Conr. 



*Siliqua patula Dixon. 



*Mytilus edulis L. 



*Venericardia ventricosa Gld. 



Mactra sp. 



Oyster sp. 



* Still living. 



