REPORT OF THE STATE PALEONTOLOGIST 1902 1141 



harie counties. Orthothetes interstriatus Hall, 

 Spirifer eriensis Grabau, Trochoceras gebhardi 

 Hall, Leperditia scalaris Jones. Two species, Cya- 

 thophyllum hydraulicum Simpson and Whitfield- 

 ella sulcata Van., occurring in the Oobleskill in Erie county, 

 are also found in the Oobleskill at Union Springs. 



In the study of this fauna Dr Grabau obtained a good clue, 

 which if followed would undoubtedly have enabled him to estab- 

 lish the true position of the Oobleskill, or " Coralline ", of Scho- 

 harie county. Having followed however Hall's correlation of 

 the " Coralline " as the eastern representative of the Niagara, he 

 concluded "that the Manlius (= Oobleskill) limestone fauna 

 of the Niagara region is a late return of the Coralline limestone 

 fauna, at the close of the long interval during which the Salina 

 shales were deposited in the Siluric seas of this region." 



Oobleskill of the Hudson river valley 



In the opening sentence of the original description of the " Cor- 

 alline " limestone Hall 1 briefly refers to its occurrence in the 

 Hudson river valley as follows : " In the neighborhood of 

 Schoharie, and extending along the base of the Helderberg moun- 

 tains and along the Hudson river, there is a thin mass of lime- 

 stone, characterized by an immense number of corals, chiefly 

 favosites, and which forms a band so distinct from any other 

 limestone that it has been for many years known by this name." 

 Hall 2 makes another reference to the presence of this limestone 

 in the Hudson river valley ; he says " The Coralline limestone 

 exists in place at several localities on the east side of the Held- 

 erberg, but I have had no opportunity of examining these places 

 in detail. It is not improbable that many more species may be 

 added to those already known." 



The fauna of this limestone in the Hudson river section how- 

 ever remained unstudied. Darton has given us much relative 

 to the occurrence of this limestone in Greene and Ulster counties, 

 Dale and Davis have each made mention of its presence in the 

 quarries about Rondout where it* is typically developed, but, so 



1 Palaeontology of New York. 1852. 2:321. 



2 Palaeontology of New York. 1852. 2 : 337. 



