REPORT OF THE STATE PALEONTOLOGIST 1902 J 1 15 



can not be far from the town of Knox, Albany co., at which place 

 it is quite likely that the Cobleskill slightly overlaps the Salina. 

 Both of these formations are absent at Altamont a few miles far- 

 ther east, and the Rondout is seen resting directly on the Lorraine 

 beds. 



Rondout waterlimes 



Next above the Cobleskill is the Rondout waterlime, which at 

 Howes Cave is 40 feet thick. The Rondout is transitional into 

 the Manlius limestone above, as well as from the Cobleskill below. 

 Hall 1 has called attention to the fact that, while in western New 

 York, where the Manlius is absent, the line of demarcation be- 

 tween the Salina (^Cobleskill or "Bullhead" of Erie county) 

 and the succeeding limestone (Onondaga) is very conspicuous, in 

 eastern New York the Rondout, then regarded as the Salina, 

 gradually gave way to conditions under which the Manlius lime- 

 stone was formed. Regarding the " Bullhead " as Cobleskill, it 

 will be seen that in New York, with the possible exception of 

 Schoharie county, there appears to be no unconformity between 

 the Salina and the overlying rock. The transition of the 

 Rondout into the Manlius as observed in eastern New York is 

 also to be noted at Cayuga lake, and these same conditions 

 probably exist at least as far west as Seneca county, beyond 

 which the Rondout and the Manlius have not been distinctly 

 recognized. 



The transition from Cobleskill to Rondout is marked by a 

 change from the limestone of the Cobleskill to the cement of the 

 Rondout. The weathered surface of the upper portion of the 

 Cobleskill varies slightly from the weathered Rondout, but fresh 

 fracture clearly shows the distinctive character of the cement 

 rock. The fauna of the lower Rondout, though much reduced in 

 force, is distinctively a Cobleskill fauna. Hall found H a 1 y- 

 sites catenulatus in the Rondout of Herkimer county, 

 and recently Prof. J. J. Stevenson 2 called attention to the fact 

 that Favosites niagarensis Hall is found abundantly 

 in the lower 3 feet of the Rondout (cement) at Howes Cave. The 



1 Palaeontology of New York. 1852. 2:339. 



2 N. Y. Acad. Sci. Ann. v. 13, no. 3, p. 365-66. 



