REPORT OP THE STATE PALEONTOLOGIST 1902 1120 



In the beginning of this paper I have called attention to the 

 fact that the original fauna from the " Coralline " limestone as 

 described by Hall contained but little that was truly Niagaran in 

 character. An examination, however, of the above list will show 

 that the species which are known to occur outside of the Cobles- 

 kill limestone are largely Niagaran species. In this case, how- 

 ever, these species are not indicative of the age of the Cobleskill, 

 but must be looked on as the return of the Niagara and Guelph 

 faunas after the long interval during which the Salina shales of 

 central New York were deposited, and during which these faunas 

 suffered such changes as time and environment would produce. 



A number of CobleskiU species continued their existence into 

 the Rondout; and, so far as they have been observed, all the 

 species that have been found near the base of the Rondout, with 

 the exception of the Eurypterus, are forms also found in the 

 Cobleskill, but none of the gastropods or cephalopods of the 

 Cobleskill appear to pass upward into the Rondout. 



Cobleskill section at Union Springs, Cayuga lake 

 The studies of Vanuxem extended as far west as Cayuga lake, 

 the western limit of the third district. The last place where a 

 line is sharply drawn between the Salina and the Waterlime rec- 

 ognized as consisting of three groups, is at Waterville, in Oneida 

 county. From that place to Cayuga lake only one locality is 

 mentioned where the brownish limestone, so characteristic of 

 the base of his Waterlime group in the eastern end of the district, 

 follows the Salina. This locality is near Jamesville, in Onondaga 

 county. A number of quarries are mentioned about Cayuga lake, 

 and a final disappearance of the group under the lake. The 

 stratigraphic position of these quarries, however, is not clearly 

 indicated. 



In this connection it is interesting to note that Hall in speaking 

 of the fourth or upper deposit of the Salina group, says i 1 



In Seneca county it does not appear in its usual characters ; the 

 highest rock of the group being a fine grained, dark colored, and 

 grayish brown mass, which apparently represents the lower part 



1 Geol. N. Y. 4th Dist. 1843. p.129. 



