The Rogers Gap Fauna of Central Kentucky 121 



Cornishville limestone and the base of the Fulton layer. The 

 name Cynthiana was chosen because this formation appeared to 

 present strong lithological and faunal changes on being traced 

 from the line of exposures including Flanagan, Winchester, Paris, 

 Millersburg, Carlisle, and Pleasant \^alley, westward across the 

 axis of the Cincinnati geanticline ; because the town represented 

 a sort of intermediate area between the eastern and western phases 

 of this formation ; and because it was one of the most northern 

 points at which the exact contact between the top of the Lexing- 

 ton and the base of the Cynthiana formation could be seen. The 

 character of the base of the Cynthiana formation here, however, 

 is quite different from that seen north of Flanagan and north of 

 Paris. There is no horizon at which All onychia -Ranaganensis is 

 abundant. There is no abundance of Orthorhynchula nor any 

 typical development of the Millersburg fauna. 



The exposures at Cynthiana occur along the railroad, one mile 

 north of the station, where the railroad approaches the river. 

 Flere massive, coarse-grained limestone, corresponding to the Ben- 

 son member is exposed above river level for a height of 19 feet. 

 The lower part of the limestone is cross-bedded, and Rhynchotrema 

 incrchescens, DalmancUa sp., and Hebertclla fvankfortcnsis is com- 

 mon also 11 feet above river level. Overlying the massive, coarse- 

 grained Benson limestone are more argillaceous limestones inter- 

 bedded with softer layers, weathering into alternations of com- 

 paratively thin-bedded limestone and clay. That part of this argil- 

 laceous section which lies below railroad level is poorly exposed 

 for fossil collecting, but the overlying parts have been quarried 

 sufficiently west of the railroad to provide a considerable fauna. 

 The strata bear a lithological resemblance to those at Rogers Gap, 

 but no specimens of Eridortliis, Clitamhoiiitcs or even of Plectani- 

 honitcs or Trimicleus were found. Moreover, the Cyclomena seen 

 here is taller and more like typical C. z'oricosuui. On the other 

 hand, species of Constcllaria, Pcrenopora, Dahnanclla, Hehertella, 

 Plat\strop/iia, Byssoiiychia, Liospira, Isotelus, Calymene, and Pro- 

 etus, resembling those found in the Rogers Gap beds, occur. For 

 the present, these beds are regarded as belonging below the Mil- 

 lersburg member. 



