Review of the New York Geological Reports. 



303 



tons, green carbonate and spiculce of native copper, have been 

 discovered in the Fentamerns rock. 



Hall has observed " slightly tortuous ridges, standing out in 

 bold relief on the surface of some of the lower strata ;" these he 

 denominated casts of mud-furrows. 



The fossils of the Clinton group are various and interesting, 

 though on account of the protean lithological character of the 

 mass, they are not so persistent over a wide area as some of the 

 organic remains of other members of the New York system. 

 Fucoids are most common in the shales and shaly sandstones. 



The lower limestone is remarkable for the number of Bra- 

 chiopoda, of the forms here represented. 



ffl 



