STRATIGKAPHY O / O 



past, in Maryland, the thickness of this formation is about 250 feet. It 

 is not improbable that it should be made to include part of the strata 

 referred to the overlying Permian — a problem awaiting further in\es- 

 tigation. 



Members. — It comprises the following members in descending ordei- 



Waynesburg coal ? 



Waynesburg limestone. 



Uniontown sandstone. 



Uniontown coal ? 



Benwood limestone. 



Upper Sewickley sandstone. 



Upper Sewickley coal. 



Lower Sewickley sandstone. 



Lower Sewickley coal ("Tyson coal"). 



Sewickley limestone. 



Cedarville sandstone. 



Redstone coal, upper bench. 



Redstone sandstone. 



Redstone coal, lower bench. 



Upper Pittsburgh sandstone. 



Pittsburgh coal. 



The Permian system is represented in Maryland by the Washington 

 and Green formations, which are preserved only in a few small areas, 

 on the tops of the highest hills, where the}^ are little exposed. They 

 are without commercial coals and have been but little studied. Their 

 further discussion will be reserved for a later publication. 



TABLE SHOWING GEOLOGICAL AND GEOGRAPHICAL DISTRIBUTION OF 



MARINE SPECIES 



The following table contains a list of the marine species found in 

 the Coal Measures of Maryland and gives their geological range and 

 distribution in other parts of the Appalachian basin. It is furnished 

 by W. Armstrong Price. 



