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NEW YORK STATE MUSEUM 



transition of the Rondout from the Cobleskill and the gradual 

 passage into the Manlius were clearly recognized by Professor 

 Stevenson, and, had he carried his observations a little farther, 

 their true significance might have been realized. The gradual 

 change from the Cobleskill, which he regarded as the Niagara, 

 into the succeeding formations he explained by saying, " It is 

 sufficiently evident that, while the great mass of Salina shales 

 was in process of deposit in central New York and in much of 

 the Appalachian region, the conditions within this portion of New 

 York changed so gradually as to bring about only a slow disap- 

 pearance of the fauna/' 



From similar observations, based on the section at Rondout 

 N. Y„ Messrs Ulrieh and Schuchert 1 have correctly concluded 

 that the so called " Clinton " of Schoharie county is really Salina. 

 There is no doubt, however, that they did not properly construe 

 the section at Rondout in assuming that the " Coralline " as there 

 developed is equivalent to the Cobleskill of the Schoharie section. 

 It will be shown from the sections in Ulster county that, while 

 the Cobleskill is present, the " Coralline " of that region repre 

 sents an age earlier than the Cobleskill. It may be here stated 

 that, while Hall wrongly concluded as to the age and position 

 of the Cobleskill in Schoharie county, he was more nearly right in 

 his estimation of the age of the " Coralline " of Ulster county, 

 though his conclusion in regard to the latter evidently was based 

 on the Schoharie section. 



Fossil localities of the Cobleskill in Schoharie county 



The Cobleskill limestone is more or less fossiliferous through- 

 out its extent in Schoharie county, and the following lists repre- 

 sent the collections made from its various outcrops. The sections 

 will be taken up in order, beginning with the most easterly and 

 extending along the line of outcrop into the western part of the 

 county. 



On the Stevens farm south of Shutter's Corners and 3 miles 

 eas1 of Schoharie the Cobleskill is partly exposed for some dis- 

 tance. This lias proved to be the best collecting ground for 



1 \. Y. State Paleontologist. An. Rep't, 1901. p. 650 (foot note) 



