1 





Professional Paper No. 47 



Series C, Systematic Geology and Paleontology, 76 



DEPARTMENT OF THE INTEKIOIi 

 UNITED STATES GEOLOGICAL SURVEY 



CHARLES D. WALCOTT, DIRECTOR 



T li E 



TERTIARY ANT) QUATERNARY PECTENS 



OF CALIFORNIA 



R^VLPH ARNOLD 



WASHINGTON 



GOVERNMENT PRINTING OFFICE 



I 9 (i 



S-^ctional Llbrcny 



Zl5g1^ 



