338 GEOLOGY OF OHIO. 
They are observable, though not yet with the same definite limitations, 
in Michigan and [linois. 
The Tully Limestone.—This has not yet been seen in Paulding county, 
but is visible in the Auglaize River, in N. E. 4 section 9, Defiance, Defi- 
ance county. It constitutes the upper member of the Hamilton, and is 
marked in Delaware county by large lamellibranchiate fossils. (See also, 
Geology of Delaware County.) 
The Hamilton Inmestone.—This limestone is known to underlie the 
north-eastern portion of the county, and to present many indications of 
being én situ in the township of Paulding, near the center of the county. 
Its line of contact with the Corniferous limestone is plainly exhibited by 
the frequent exposures of rock in the bed of the Auglaize where it 
crosses that river in Auglaize township. The lowest outcropping rock 
overlying the Corniferous (“‘Delhi beds” of Delaware county) is seen at 
the quarry of Samuel Doyle, at the mouth of the Little Flatrock (N. EH. 4 
section 30), which joins the Auglaize about three-quarters of a mile north 
of the Flatrock.* This quarry furnished the stone put in the aqueduct 
at Royal Oak (Newberg on the maps) fifteen years since. At the quarry 
the beds are firm and uniform, showing but little shaly tendency, with 
dip north and north-east. Some are taken out that have a thickness of 
twelve or eighteen inches. It is of a dark, blackish blue, and is, on 
weathering, found to be charged with Hamilton fossils. At the quarry 
but few could be identified, owing to the high stage of the water, but the 
following species were seen in the stone put in the aqueduct, where the 
long exposure has caused it to check into hundreds of thin beds, and, by 
‘the disappearance of the shaly parts, to disengage numerous well-pre- 
served fossils. These beds are rarely or never crystalline, except that 
occasional calcite appears in the interior of the shells, but the massive 
abutments are crumbling away. Atrypa reticularis, Cyrtia Hamiltonensis, 
a handsome Orthis, Spirifera mucronata, Spirifera (large species, resembling 
garded as purely Hamilton, though it contains many fossils which are usually called 
Hamilton fossils, but all these, with perhaps the exception of Spirifera mucronata, are 
-also found in the Corniferous of New York. And it also contains fossils which are 
regarded at the east exclusively Corniferous; such as Spirifera gregaria, Pentamerus 
aratus, Strophodonta hemispherica, Tentaculites scalaris, and others. It also contains 
many fossil fishes and mollusks, which are abundant and characteristic fossils of the 
-Corniferous in Ohio. . 
I also regard the separation of the Lower Corniferous into two members, and their 
identification with the Corniferous and Onondaga limestones of New York, as prema- 
ture, since it is as yet sustained by no paleeontological evidence. This subject will be 
found more fully discussed in Vol. L., Part I., pp. 144 and 149 of this Report, and in 
~ the Report on Erie County. | J. 8. N. 
* The Indians called the Flatrock Crooked Creek, and that name still prevails on the 
rmaps. 
