338 GEOLOGY OF OHIO. 



They are observable, though not yet with the same definite limitations, 

 in Michigan and Illinois. 



The Tully Limestone.— This has not yet been seen in Paulding county, 

 but is visible in the Auglaize River, in N. E. £ 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 Limestone.— This limestone is known to underlie the 

 north-eastern portion of the county, and to present many indications of 

 being in 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. E. \ 

 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 



; garde<i as purely Hamilton, though it contains many fossils which are usually called 

 .Hamilton fossils, but all these, with perhaps the exception of Spirifera mucronata, axe 

 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, Tenlaculites 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 palaeontological 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. s. n. 



'* The Indians .called the Flatrock Crooked Creek, and that name still prevails on the 

 tmaps. 



