298 STUART WELLER 



suggest the regular courses in a well-built masonry wall. The 

 weathered surfaces of the cliffs become darker colored than the 

 freshly broken rock, and in places more or less iron stained. The fos- 

 sils of the Cypress sandstone consist of more or less fragmentary 

 plant remains, the only recognizable form being Lepidodendron 

 trunks. 



It has not been possible to measure the exact thickness of the 

 Cypress sandstone in any section in the southern counties of 

 the state. The base of the formation, resting upon the Paint 

 Creek shale, can be approximately determined in many places, 

 but the top of the section in these same sections is in all cases 

 missing and the upper portion has- been more or less reduced by 

 weathering. The greatest actual thickness that has been observed 

 in a cliff is about 70 feet, but the thickness has been estimated as 

 no feet in at least one section, and the average thickness across 

 these counties is about 100 feet. 



In tracing the stratigraphic position of the Cypress sandstone 

 into the section of the Chester series of the Mississippi River 

 counties, the sandstone is found to be much reduced in thickness 

 and much less massive in character. In this section, as originally 

 described by the writer,^ a sand and shale formation overlying the 

 Paint Creek limestone was named the Ruma formation. The later 

 study of the section in the more southern counties has shown that 

 the sandstone of the Ruma should be considered as the thinned- 

 out margin of the Cypress sandstone, and that the shales below 

 should more properly be considered as being a part of the Paint 

 Creek. With this interpretation the name Ruma becomes super- 

 fluous, and Cypress may be extended to include these sandstone 

 beds of the Ruma in Monroe and Randolph counties. In follow- 

 ing the section still farther, into Missouri, it is found that the 

 Cypress sandstone disappears entirely, and the super-Cypress 

 limestones rest directly upon the Paint Creek. 



In a recent contribution Uhich^ has proposed the correlation 

 of the Cypress sandstone of the southern counties with the Lower 



^Weller, Trans. III. Acad. Set., Vol. VI (1914), p. 126; also III. State Geol. Surv., 

 Monog. I (1914), p. 26. 



= "The Formations of the Chester Series in Western Kentucky, and Their Corre- 

 lates Elsewhere," Ky. Geol. Surv., Plate D, opposite p. 47. 



