ROSS COUNTY. 645 



corals, univalve shells, and chambered shells. The beds on Paint Creek, 

 for a dozen miles below the last named point, are occupied very largely 

 by casts of Megalomus. This remarkable fossil occupies nearly, or quite, 

 ninety feet of limestone, near the mouth of the Rocky Fork of Paint. 



As the Helderberg limestone is followed to the southward and east- 

 ward it is observed to thin out very rapidly. An excellent section — one 

 of the best in this whole region — is found on the banks of Buckskin 

 Creek, two miles north of Bainbridge, on the Greenfield road. The 

 Megalomus beds of the Niagara, the Helderberg (waterlime), and the 

 Huron shale are all shown in a section of fifteen feet. In other words, 

 the Megalomus beds reach up almost to the shales — a thin wedge of Hel- 

 derberg alone separating the two formations. 



It will be remembered that a few miles to the south-westward the 

 Helderberg disappears in places entirely, the Huron shales lying upon 

 the Niagara strata. The uppermost member of this formation at this 

 point is a peculiar sandstone, which has been described as the Hills- 

 borough sandstone. There are a few exposures of this sandstone in Pax- 

 ton township, in the vicinity of the caves of Rocky Fork. 



We find in the great exposure of limestone at the Falls of Paint, in 

 the beds that underlie the Megalomus division, another of these fossils 

 above named in equal abundance. The casts of Pentamerus oblongus here 

 make up the very substance of the rock. 



As Paint Creek turns in the extreme south-western corner of the 

 county abruptly to the north-east, the heavy easterly dip of the lime- 

 stones soon buries them below the surface. Their last appearance is op- 

 posite the village of Bainbridge. 



An admirable general section of the rocks of the western side of Ross 

 county is furnished by Benner's Hill, in the same neighborhood. The 

 summit is five hundred feet above the valley, and the following scale— 

 the formations being represented in their true order-vis shown in the 

 steep ascent : 



Upper beds of Waverly group (Buena Vista division,.etc.) 42 



Waverly black slate 15 



Waverly quarry courses 31 



Waverly shales 50 



Huron stales 332 



Helderberg limestone (waterlime) 15 



Niagara limestone (Megalomus division) 15 



Both of the limestones here shown are capable of furnishing an un- 

 limited supply of lime of the highest quality. It is not, indeed, sur- 

 passed in whiteness, mildness, and durability by any lime of the State.' 



