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NEW YORK STATE MUSEUM 



of the rock, it is a limestone. In the western sections, where the 

 corals common to the eastern portion are very rare, it is a dolo- 

 mite. The petroleum odor so characteristic of the Cobleskill in 

 Erie county is not observed in the eastern sections. In Erie 

 county the rock is filled with cavities, due to the dissolving out of 

 the corals, but in Schoharie county the corals often appear to be 

 the most resistant portion of the rock. In both sections the Coble- 

 skill is in some portions rich in iron pyrites. In the three sec- 

 tions where the Cobleskill has been mainly studied it varies but 

 little in thickness; at Buffalo it is 8 feet, 4 inches, at Union 

 Springs 8 feet, 6 inches and in Schoharie county it averages 6 

 feet. 



In view of our present studies, the most interesting feature 

 of the Cobleskill of P>ie county is the fauna which it contains. 

 Of this fauna a careful study has been made by Dr A. W. Grabau. 1 

 From this limestone he recognized 12 species, to which has been 

 added a species of Favosites. The following species have been 

 identified from the Cobleskill of Erie county. 



1 Nematophyton crassum Penhallow 



2 Cyathophyllum hydraulicum Simpson 



3 Favosites sp. 



4 Orthothetes interstriatus Hall (— O. hydraulicus Whitfield) 



5 Spirifer eriensis Grabau 



6 Whitfieldella sulcata Van, 



7 W. nucleolata var. 



8 W. cf. laevis Whitfield 



9 Rhynchonella sp. 



10 Loxonema ? 



11 Pleurotomaria ? 



12 Trochoceras gebhardi Hall 



13 Leperditia scalaris Jones 



A rather minute analysis of this fauna convinced Dr Grabau 

 that it was closely related to the fauna of the Cobleskill, or 

 " Coralline ", limestone of Schoharie county, a conclusion which 

 is strengthened by a recent comparison of the two faunas. The 

 following species are common to the Cobleskill of Erie and Scho- 



1 Buffalo Geol. Soc. 1900. 1 1 : 351-55, 3(53-73. 



