Bull. TJ. S. Geol. and Geojrr. Survey, Vol. III. 



Plate 30. 



Plate 30. — Sections of Cretaceous Formations. 



[N. B.— In Fip. 2, the lower bracket, after "Cret. No. 4", should include only "Black Carbonaceous and 

 Alkaline Shale". ] 



