624 L. C. SNIDER 



and limestone occurring locally at the base of the formation which 

 are correlated with the Fern Glen formation of Missouri and lUinois. 

 The great portion of the Boone is of Burlington-Keokuk age. The 

 Warsaw, Salem, and Ste. Genevieve are supposed to be absent, the 

 formations above the Boone being of Chester age. At the base of 

 the Chester is a formation consisting principally of limestone which 

 is very thin along the southern part of the area, but thickens to at 

 least loo feet along the western side, where the unconformity 

 between it and the Boone is very marked. The Fayetteville shale 

 thins from the Arkansas line westward and northward. The sand- 

 stone member (Wedington) disappears and limestones become 

 more important. The Pitkin limestone thickens and becomes 

 more regular in thickness westward from the Arkansas line into 

 the Muskogee quadrangle, and then thins rapidly and becomes 

 argillaceous and ferruginous to the northward. In the Pryor and 

 Vinita quadrangles it was locally removed by erosion before the 

 deposition of the overlying Pennsylvanian rocks. 



It should be repeated that the work on these rocks is still in 

 progress and that this paper is merely a statement of the facts con- 

 cerning them so far as they are known at present. The faunal 

 lists given are admittedly very incomplete, their aim being to list 

 only the better known or more abundant species. 



