42 BULLETIN OF THE MUSEUM OF COMPARATIVE ZOOLOGY. 



Ptoiie by the Rev. Augustus Wing, that formation is determined to be of Lower 

 Silurian age, and to represent rocks not older than the Cambrian, and not 

 newer than the Trenton. 



In Vermont the rocks of a belt of slate which is continuous with the schists 

 of the Richmond Range in Berkshire County, are found to overlie the Eolian 

 limestone, and thus the slate series is more recent than that formation, and is 

 considered to represent the Hudson River slates. 



On these grounds. Professor Dana concludes that the limestones of Berkshire 

 are of Calciferous, Quebec, Chazy, and Trenton age, while the schists are of the 

 age of the Hudson River slates. 



On the supposition that the limestone of the Richmond Valley represents a 

 series of beds bent double, the thickness of the series is at least 5,000 feet, and 

 on the same supposition the thickness of the mica schist series in the Lenox 

 Range is 4,500 feet, making 9,500 feet of Lower Silurian strata. 



May 15, 1878. 



