96 Cincinnati Society of Natural History. 



inclined to accept Mr. C. I). Walcott's suggestion to refer to 

 these rocks as the Cincinnati shale and limestone in the Hud- 

 son Terrane.* 



Upon the organization of the vSecond Geological Survey of 

 Ohio, under Dr. J. S. Xewberr}-, special attention was naturally 

 directed to the rocks in the vicinity of Cincinnati, and in the 

 first volume of the final report, t Prof. Kdw. Orton proposed 

 to divide the rocks into three series as follows : 



Lebanon Beds, 293 feel. 



Cincinnati Beds, proper, 425 " 



Point Pleasant Beds, 50 " 



Total, 76.S feet. 



The Cincinnati Beds are again divided into the — 



Hill Quarry Beds, 125 feet. 



Eden Shales, 250 



River Ouarry Beds 50 



Total, . 425 feet. 



Details are given of these different series, together with an 

 account of the fossils obtained from various strata. 



It is to the lowest division of the Cincinnati rocks, called 

 by Prof. Orton the Point Pleasant Beds that particular atten- 

 tion is directed at the present time. This series is stated to 

 contain the lowest rocks of the State, and it takes its name 

 from the exposure at Point Pleasant, a little settlement on the 

 Ohio, some twenty-five miles above Cincinnati. The beds of 

 the series begin at low water mark at Cincinnati, and descend 

 gradually toward the east as far as Point Pleasant, when they 

 rise again. At this point the strata are about fiftv feet in thick- 

 ness, below the lowest level of the Cincinnati rocks. They 

 have been described by Prof. Orton as being lighter in color 

 than the ui)per courses, and to be sometimes slat\- in struct- 

 ure, " while in others they have a tendency to a.ssume lentic- 

 ular forms of concretionary origin, sometimes to such an ex- 

 tent as to destroy their \alue as building rock. The layers 



"■Value of the Icnn Hudson Rivc-r Croup in Cfologic Nomenclature, null. Gcol. 

 Soc. of Am , vol. I, 1S90, pngc 353. 

 fCcoloify, vol. I. 1873 page 373. 



