Clark and 

 18f 



Rarii 



8< 



Pata 



j 



i 



i 



r 



Arun 



PatU 



N. H. Darton, 



1893. 



J. S. Newberry, 

 1895. 



Magothy. Amboy clays. 



Potomac. 



L. F. Ward, 



1895. 



O.C. Marsh. 

 1896. 



Island series. 



Albirupean 

 series. 



Iron ore 

 series. 



A quia Creek 

 series. 



Mt. Vernon 

 series. 



Rappahan- 

 nock series. 



Potomac 



or 



Jurassic 



Formation. 



James River 

 series. 



