THE DELAWARE LIMESTONE 417 



itself, though containing some fossils which are common to the Hamilton and the 

 Corniferous, has never yielded me any exclusively Hamilton fossils. 1 



In 1875 Professor Winchell read a paper "On the Parallelism 

 of Devonian Outcrops in Michigan and Ohio" before the American 

 Association, in which he gave a table of parallel "Devonian Outcrops 

 in Michigan and Ohio," in which Sandusky, Delaware, Marion, 

 and sec. 17, Defiance, Defiance County, Ohio, are correlated with 

 the Hamilton blue limestone as exposed in the vicinity of Thunder 

 Bay, Lake Huron, and near Charlevoix, Lake Michigan, in the 

 northern part of the Lower Peninsula. 2 



Dr. Newberry's objection was restated in the succeeding state 

 report under the "Review of the Geological Structure of, Ohio," 

 where he expressed this opinion: 



In regard to the position of the Sandusky limestone, it must be said that the 



weight of evidence is in favor of retaining it in the Corniferous There is 



even in New York much in common between the fossils of the two groups, and 

 all the fossils which Professor Winchell relies upon as criteria for distinguishing 

 the Hamilton from the Corniferous, are found in both; hence their presence in 

 the Sandusky limestone is no proof of its Hamilton age. It should also be said 

 that quite a number of fossils are found in the Sandusky limestone which are 

 regarded as characteristic of the Corniferous. 3 



This volume contains Dr. Orton's report on the geology of Franklin 

 County, in central Ohio, in which he followed Dr. Newberry in cor- 

 relating all of the Devonian limestone with the Corniferous. The 

 upper division, however, of thirty-two feet of blue limestone he 

 states is, "from its occurrence at Delaware, and the extensive use 

 made of it at that point, well named the Delaware limestone;"* and 

 this name was used in place of Newberry's older one of "Sandusky 

 limestone." For the lower division Dr. Orton retained the name 

 "Columbus limestone," and described a six-inch stratum named 

 the "bone-bed" containing large numbers of the teeth, plates, and 



1 Ibid., footnote, p. 290. For similar statements see Dr. Newberry's criticism 

 of Professor WincheH's geological classification of Paulding County . (footnote, 

 pp. 337, 338); and Dr. Newberry's description of the Corniferous limestone of Erie 

 County (pp. 191, 192). 



2 Proceedings 0) the American Association for the Advancement 0} Science, Vol. 

 XXIV (1876), Part II, p. 59. 



3 hoc. cit., Vol. Ill, Part I (1878), p. n. 4 Ibid., p. 606. 



