530 Geological Society. 



Carboniferous limestone. — The masses belonging to this forma- 

 tion are next in abundance to those derived from the traps. When 

 large they are much scratched longitudinally and transversely ; and 

 the angles are sharp. 



" A note by Mr. Murchison on a Section and a List of Fossils from 

 the State of New York," by James Hall, Esq., was likewise read. 



Mr. Murchison says, that in consequence of the researches of Mr. 

 Featherstonaugh, Mr. Conrad, Mr. Hall, Mr. Vanuxem, Mr. R. C. 

 Taylor, and other geologists, large tracts in the British colonies in 

 North America and in the United States have been for some time 

 known to be composed of formations containing Silurian, old red 

 sandstone and carboniferous fossils. Mr. Hall's section, presenting 

 a tabular view of the succession of formations, commences with the 

 red sandstone of Blossburgh in Pennsylvania, proved to be the Repre- 

 sentative of the old red sandstone or Devonian system of Great Bri- 

 tain, in consequence of its inclosing remains of Holoptychius and 

 Coccosteus. This deposit is succeeded in descending order by others, 

 referable, on account of their testaceous remains, to the lower part of 

 the same system, and these are again underlaid by limestones and 

 shales, especially at Lockport and Rochester, charged with Ptilo- 

 dictya lanceolata and other Silurian corals and fossils. The lowest 

 deposit alluded to by Mr. Hall is the Medina sandstone. The fol- 

 lowing sectional list, in descending order, is copied from his com- 

 munication : — 



Red sandstone. 



Sandstone and shale, abundance of fossil shells. 



Shale, with thin layers of sandstone ; Fucoides, abundance ; few 

 shells. 



Green and black shale, several hundred feet thick. 



Black shale. 



Moscow shale. 



Encrinal limestone. 



Ludlowville shale. 



Thin mass, with Bellerophons. 



Shale. 



Thin limestone, with fossils. 



Marcellus shale. 



Limestone, with hornstone. 



Onondaga limestone. 



Onondaga saliferous group, containing gypsum and salt-springs. 



Lockport limestone. 



Rochester shale. 



Limestone. 



Green shale, with fossils. 



Pentamerus limestone. 



Green shale and iron ore. 



Red and grey sandstone, Medina sandstone*. 

 With respect to the Onondaga saliferous group, Mr. Murchison 



* For detailed accounts of the New York Devonian and Silurian Systems 

 and their Organic Remains, see the Geological Reports of the State for 

 1838, 1839, 1840. 



