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Cincinnati Society of Natural History. 



the only fossil suggesting such affinities. On account of the many 

 good exposures of this argillaceous limestone formation near Belfast, 

 in Highland County, Ohio, it is called here the Belfast bed. Its 

 usual thickness is between 3 and 6 feet. 



West of its eastern line of outcrop, the Belfast formation does 

 not maintain the same characteristic structure. If it is represented at 

 Morris Hill, half a mile northeast of Dodd's Station, it is only in the 

 form of a brownish shaly stone. On the Marian Clark farm, about 

 half a mile west of Lytle, a layer similar to the Belfast bed, but only 

 7 inches thick, is overlaid by 12 inches of blue clay, and underlaid by 

 15 inches of the same material. On the Thorp farm, two miles north- 

 west of Waynesville, and two miles directly east of Lytle, the Clinton 

 is underlaid by about 3 feet and a half of blue clay in the gully, and is 

 represented by fine, fissile, brownish shale in a side branch nearer 

 the barn. At Centreville the Clinton is underlaid by about 30 inches 

 of a firm blue massive rock, finer grained than the usual Belfast rock. 

 At Huston's quarry the Clinton is underlaid by about 6y 2 feet of 

 brown shales, rather firm and sandy, hardly clayey. At the Soldiers' 

 Home quarries there is no rock underlying the Clinton in anyway cor- 

 responding to the Belfast bed, unless it be a clay layer containing Qrthis 

 occidentalis. At Fauver's quarry, about two and a half miles north 

 of Dayton, about 22 inches of shaly blue clay and 20 inches of 

 hardened blue clay underlie the Clinton. On the Keplinger farm, 

 about half a mile east of Tadmor, about 24 inches of fairly solid, mass- 

 ive, greenish blue rock underlying the Clinton represent the Belfast 

 bed. In the Charlestown Falls section, 42 inches of a rather firm 

 blue rock, massive, in thick courses, represent the Belfast bed. They 

 are underlaid by 34 inches of thinner, more shaly rock, and then by 9 

 inches of limestone, presumably Lower Silurian. At the High Banks, 

 3 miles south of Troy, 6 2 3 feet of a light brown rock are found beneath 

 the Clinton. It occurs in layers 2^ and 3 inches thick, frequently 

 traversed by vertical cracks, and more firm than the shales beneath. 



West of the line of outcrop of the typical Belfast bed this bed is 

 therefore represented by rock having somewhat different lithological 

 characteristics. These differences are well marked towards the south- 

 west where shales or even blue clays seem to represent this horizon in 

 many localities. They are less marked in the intermediate regions 

 from Dayton northward, where the corresponding rock is firmer, in 

 contrast with the more frequently parted softer shaly rock beneath. 



