Williams J STEVENSON. 125 



The section below Selin's Grove is as follows: 



Feet. 

 Genesee slate 264 



Hamilton group 2 922 



Marcellus slate 300 



Selin's Grove lower limestone o. r > 



Selin's Grove shale 140 



505 



This is the "Middle type." 



The third or " Southern type" is exhibited at a railroad cut two miles 

 below Georgetown. 



Feet. 

 Concealed 400 



Selin's Grove upper sandstone 300 



Selin's Grove shales 325 



Selin's Grove lower sandstone 100 to 50 



Marcellus? .... 25 



Selin's Grove lower limestone 75 



Gray shales 50 



Oriskany saudstone, VII, placed in the Silurian by Mr. White, varying from 40 to 

 in thickness. 



In the Campbell's Ledge black slate, immediately below the Pottsville 

 Conglomerate, sixty-three species of plants and six fossil insects were 

 obtained, a few of them suggesting " Subcarboniferous types," but the 

 great majority were of the coal flora, known only from the Pottsville 

 Conglomerate. l 



High up in the rocks called Catskill, fossils of Chemung species were 

 reported, as Spirifera disjuncta and 8. mesostrialis. 2 This was some 

 three hundred feet above Holoptychius remains. 



Several species regarded as of characteristic Chemung age in New 

 York were reported from several horizons in the Chemung-Catskill 

 group. These, too, are well above red shales which had been regarded 

 as at least as high as Catskill formations. In the Chemung, typical 

 Chemung species were reported, but in combinations not precisely those 

 commonly seen in the typical New York sections. The "Tully" was 

 not recognized by its fauna, but on account of resemblance lithologi- 

 cally to the Tully limestone of New York. 3 The "Hamilton" is iden- 

 tified by typical Hamilton species. Thus is the "Oriskany" also distin- 

 guished. The identification of species is credited to Prof. B. W. 

 Claypole. 



The report called out sharp criticism, first in the letter of transmis- 

 sion by the State geologist who wrote : 



The paleontology of this report requires the closest consideration, and presents 

 some difficulties of considerable magnitude, I have, therefore, submitted the proof 

 sheets to our highest authority, Prof. James Hall, of Albany. 4 * » * 



Prof. Hall objected to considering the Holoptychius bed as the base 

 of the Catskill, because of the occurrence of Chemung species higher up. 



1 Hep. of Prog. G 7 , p. 39. 2 Ibid., p. 57. »Ibid.,p.76. * Ibid,, p. xix. 



