]\LVUYLAXD GliOLCXUCAL SuRVEY 105 



late Cayugan age as shown by the general composition of its fauna. 

 Eecent studies of the writer tend to show that the Tonoloway is probably 

 the same as the Bossardville of Pennsylvania and New Jersey. 



Keyser Member 



The presence of the Keyser member of the Helderberg in parts of West 

 Virginia adjacent to Maryland is shown in the description of the Mary- 

 land sections. The relation of the Keyser member to strata of the same 

 age in Pennsylvania, New Jersey, and New York will now be considered. 



Correlation with Pennsylvania. — The Keyser limestone has been 

 traced continuously from j\Iary]and into southern Pennsylvania and has 

 been fouiul to possess tlie same lithology and faunas in both areas. 



It is present also in central Pennsylvania where the same features are 

 clearly recognizable, establishing the essential identity of the beds in both 

 regions. Its relations will be seen best by the examination of a few typical 

 sections in the area. The sections described were examined very briefly 

 by the writer, but the relations are sufficiently clear to permit conclusions 

 as to their general similarity. 



Claypole ' described the following section at New Bloomfiold, Penn- 

 sylvania : 



Vertic 



Tot a 



jggj thickness 



thickness 



feet 



Yellow flint beds (Oriskany chert member). 



Clarks Mill Shale. 



Limestone beds with black chert 8 242.5 



Bed with Htromatopora 1 234.5 



Bed with Tentaculites and brachiopods 20 233.5 



Coral bed 0.5 213.5 



Tentaculites 3 213 



Tentaculites and some brachiopods 3 210 



Not described 2 207 



Corals 1 205 



Rhynchonella beds 2 204 



Concealed 4 202 



Uneven gray shales with limestone beds 1 198 



Concealed 8 197 



Concealed, Chwtetes and Tentaculites 1 189 



Hard dark limestone full of small C/iff^eies and brachiopods. . 3 188 



^ Kept. 2d Geol. Survey Pa., vol. F2, 1885, p. 182. 



