CONTRIBUTIONS TO PALAEONTOLOGY. 81 



SUPPLEMENTARY NOTE 



TO PAGES 95 AND 96 OF THE THIRTEENTH ANNUAL REPORT OF THE 

 REGENTS ON THE STATE CABINET. 



During the studies and comparisons of the fossils described in the pre- 

 ceding pages, I have discovered among my collections from Licking county 

 (Ohio) a specimen of the Goniatites hyas^ which I have described from 

 Rockford ( Indiana). This specimen is from the yellow sandstones and olive 

 shale and sandstone group known as the Waverly sandstone series of Ohio, 

 and which is the equivalent or continuation of the Portage and Chemung 

 groups of New-York. From the usually limited vertical range of Gonia- 

 tites in our strata, the occurrence of this fossil in such a position induces 

 me to conclude that the position assigned to the Goniatite beds of Rockford 

 may be erroneous, and that the true position is higher in the series, or more 

 nearly in a parallel wifli the Chemung group ; for I can hardly suppose that 

 a species of Goniatite common in beds of the age of the Hamilton group 

 would range so high as the Chemung group. 



The similarity of one or two of these Goniatites with Carboniferous forms 

 of Europe renders the question regarding the position of the Goniatite beds 

 of Rockford a matter of much interest ; and during the Geological Survey 

 of Iowa, I directed Mr. Worthen, then connected with that survey, to 

 make a section across the country, taking the locality of these beds in his 

 way, with a view of determining their true position. He however failed to 

 obtain an actual section from exposures of the strata at the locality ; but 

 his observations elsewhere, in connexion with those made by myself, com- 

 pelled me to the conclusion that the Rockford beds w^ere below the sand- 

 stones, which, in the Ohio and farther west, were regarded as the continua- 

 tion of the Chemung group. 



I am satisfied, from my own observations in other localities, that the 

 Goniatite beds of Rockford are associated with, or lie directly above the 

 Black slate ; and that this Black slate, on the Ohio river, apparently suc- 

 ceeds in direct sequence the limestone which is clearly a continuation of the 

 Upper Helderberg limestone of New-York. As the Hamilton group has not 

 been recognized in the south part of Ohio or Indiana, so far as I know, there 

 may yet be room for doubt as to whether this group thins out beneath the 

 black shale or above it ; or, in other words, whether the Black shale of 

 Southern Ohio and Indiana, and of Kentucky and Tennessee, may be the 

 continuation of the Marcellus shale or the Genesee slate of New-York. For, 

 as I have said elsewhere*, this rock, "from position, seems to be the equi- 

 valent of the Marcellus shale of New-York, and is the only representative 

 of that rock, the Hamilton group, and the Genesee slate ; for we pass di- 

 rectly from this to the green shales or slaty sandstones of the Portage group 

 or Waverly sandstones of Ohio." 



The discovery of this Goniatite in the latter series of Ohio suggests 

 anew the question regarding the age of the black slate near the Falls of the 

 Ohio. 



* Transactions of the Am. Assoc, of Geologists and Naturalists, 1841 & 1842, p. 280. 

 1S6L] U " [Senate No. 116.] 



