REPORT OF THE STATE PALEONTOLOGIST 1902 857 



cement rock, as at Rondout, and then reappearing after the 

 deposition of a considerable thickness of waterlimes, and the 

 second appearance followed again by more of the cement 

 rock. The lowermost of these beds is not the equivalent of the 

 typical or Schoharie county Cobleskill but its fauna carries a 

 much stronger impress of Niagaran age. We are compelled, for 

 purposes of correlation east and west, to designate this bed by 

 a distinctive term and shall call it the Wilbur limestone. 



The Cobleskill beds on Cayuga lake at Frontenac island are 

 involved in somewhat similar stratigraphic condition to the 

 upper bed or true " Coralline " at Rondout. We had undertaken 

 a few years ago to work out the various bearings of the data set 

 forth by this interesting fauna and formation, specially its 

 manifestations in central and western New York. During the 

 past season field studies have been carried forward in the eastern 

 part of the State. It is too soon to state definitely the outcome 

 of these investigations; but this much is clear at the present 

 time, that the fauna of the Coralline limestone, in its first 

 appearance in the Rondout section, contains an important 

 percentage of species which have very close relations even to 

 identity with species of the Niagara dolomite. This resemblance 

 is essentially lost in the higher horizon at Rondout which is 

 equivalent to and probably continuous with the typical Coralline 

 outcrops in Schoharie county. Several of these very character- 

 istic forms occur in the Guelph fauna, which we have elsewhere 

 described, and others, as just noted, reappear in a still later 

 manifestation, in fact the final stage of the Siluric faunas in 

 western New York. In the proper interpretation of the strati- 

 graphic relations of these faunas much will depend on the valua- 

 tion of the beds which underlie the limestone in the Schoharie 

 county sections, and which were called and have heretofore been 

 commonly granted to be of Clinton age. 



Messrs Ulrich and Schuchert put forward, in the last annual 

 report of the paleontologist, in an important paper entitled 

 Paleozoic Seas and Barriers in Eastern North America, the 

 hypothesis that, during this late Siluric period, a land barrier 

 crossed New York State from northeast to southwest, and that 

 the Coralline fauna was a provincial development pertaining to 

 the region outside or eastward of the barrier, while other phases 



