THE 



FAUNA OF THE MAXVILLE LIMESTONE. 



William Clifford JMorse, 

 Ohio State University. 





INTRODUCTION. 



The present paper represents the tinal resnlts of a study of 

 the Maxville limestone begun in 190^), the historic, stratigraphic, 

 and ecunoniic portions of which are soon to appear as Bulletin 

 13 of the Geological Survey of Ohio. In that publication it 

 was shown that the region of outcrop of the limestone is nat- 

 urally divisil)le into three parts, a Northern Area, a Central 

 Area, and a Southern Area, and that in the stratum itself, in 

 many places, may be recognized three divisions, a lower zone, a 

 middle (shale-nodular) zone, and an upper zone. The Xorth- 

 <M-n Area extends from a point near Zanesville on the north 

 to one near Logan on the south, and contains the best exposures 

 of the limestone. The Southern Area reaches from Hamden 

 on the north to the Kentucky side of the Ohio River on the 

 south, and has but a few widely separated exposures. The 

 lentral Area lies Ijetween the other two and so far as known 

 contains no exposures. The limestone of the lower zone is 

 an impure one, nearly destitute of regular bedding planes, poor 

 in fossils, and about twenty-five feet in thickness. The middle 

 zone is aljout three feet thick, and consists of alternating nodular- 

 like layers of limestone and thin intervals of shale, l)oth of 

 whicli are fossiliferous. In the upper zone, the maximum thick- 

 ness oi which is twenty-two feet, the fossils are common, the 

 limestone purer, and the medium layers are separated by shaly 

 ])artings in such a manner tliat the slratilication is the conspicu- 

 ous feature. 



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