August 4, 1905.] 



SCIENCE. 



151 



road at the northern edge of Versailles, Ind., 

 both the Hehertella insculpta horizon, at the 

 base of the Versailles bed, and the Colum- 

 naria layer, immediately below the massive 

 Tetradium layer, at the base of the Madison 

 bed, are well exposed.^ 



The name Garrard, introduced by Camp- 

 bell, in Folio No. 46, of the ' Geological Atlas 

 of the United States,' 1898, may be used not 

 only for the comparatively unfossiliferous 

 Upper Eden beds of central Kentucky, but 

 also for the equivalent, often richly fossilifer- 

 ous, beds farther north. 



Finally, the reference of the beds underly- 

 ing the Eden' opposite Warsaw, Ky., on the 

 Indiana side of the Ohio River, to the Point 

 Pleasant beds of Orton may be asserted with 

 greater confidence, since these lower beds have 

 been studied along the Ohio River as far east 

 as Stony Point, a mile and a half east of 

 Higginsport. At Point Pleasant, O., a short 

 distance west of the town, the base of the clay 

 layer with Triarthrus hecki occurs 113 feet 

 above the level of the river. From this level 

 downward almost 50 feet of rock are quarried. 

 Between the level of the river road and the 

 river, a vertical distance of fifty-five feet, the 

 exposures are very poor, and no quarrying 

 operations are carried on here. It is very 

 evident that Professor Orton referred to the 

 quarried rocks, when proposing the name 

 Point Pleasant beds. As late as 1893, in 

 volume VII. of the ' Geological Survey of 

 Ohio,' p. 4, he states distinctly that the Tren- 

 ton limestone is seen only in the Point Pleas- 

 ant quarries, if at all in the state. Professor 

 Orton did not regard the quarried rocks at 

 Point Pleasant as equivalent to the Lower or 

 River quarry beds opposite Cincinnati, al- 

 though both lie directly below the Triarthrus 

 hecM layer, and in this he has been followed 

 by other investigators. The present writer, 

 on the contrary, after an examination of all 

 the exposures along the Ohio River, has come 

 to the opposite conclusion. The observations 

 which lead to this result are chiefly the follow 

 ing: The most characteristic and unbiquitous 

 fossil in these beds all along the Ohio River 



» Am. Journ. of Sci., 1904, p. 329. 



is Eridotrypa hriareus. Even if this fossil 

 eventually should be found in the Lexington 

 limestone, it can not be common there, since 

 so far it has not been detected at all. In the 

 next place, Trinucleus concentricus is found 

 in the upper part of these beds at many locali- 

 ties. It is present opposite Warsaw; opposite 

 Cincinnati it was detected .as low as eighteen 

 feet below the top of the heavy limestone be- 

 neath the Eden section. At Point Pleasant 

 it occurs in the upper part of the section. 

 Whatever its range may be elsewhere, along 

 the Ohio River it does not extend below the 

 upper part of the rocks here identified as 

 Point Pleasant beds. It certainly , never has 

 been found in rocks known to be of Lexington 

 age. Again, the rocks are very much alike 

 lithologically. This usually does not appear 

 where the rocks have been quarried, but where 

 much weathered along the hillsides, the simi- 

 larity of the rocks at Point Pleasant and at 

 Cincinnati often is very striking. For in- 

 stance, on the hillside southwest of the rail- 

 road trestle at Foster, Ky., near railroad level, 

 the dense, fine-grained limestones with nu- 

 merous cross-sections of gastropods, and the 

 coarse-grained, more crinoidal limestones, 

 often wave-marked along the top, have an 

 appearance very much like the long-exposed 

 rocks in the Mohawkian section opposite Cin- 

 cinnati. These features are not presented by 

 the Lexington rocks in central Kentucky. 



The total thickness of rocks to be included 

 in the Point Pleasant beds, if this name is to 



Series. Divisions. 



Richmond. 



Cincinnatian. 



Maysville. 



Eden. 



Beds. 



{Saluda. 

 Versailles. 

 Waynesville. 



Arnheim. 

 Mount Auburn. 

 Corryville. 

 Bellevue. 

 Fairmount. 

 . Mount Hope. 



r Garrard. 

 J MiddleEden. 

 i Lower Eden 



L (Fulton layer' 



Mohawkian. 



{Point Pleasant. 

 Lexington 

 (top only). 



