42 BULLETIN OF THE MUSEUM OF COMPARATIVE ZOOLOGY. 
stone 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, 
