EQUIVALENCE OF EOLIAN LIMESTONE TO THE CALCIPEROUS. 513 



ness of from 3,500 to 4,000 feet by Safford. These several sections prove 

 that in the Appalachian region, extending from Georgia to the St. Lawrence 

 river and also to Newfoundland, there is a great development of limestone 

 between the Potsdam zone and the Trenton limestone which may be referred 

 to the Calciferous-Chazy zone, or the Canadian period of Dana. 



I think we owe to President Brainerd and Professor Seely our sincere 

 thanks for the valuable work they have been doing in the geology of the 

 valley of Lake Champlain. 



Professor C. H. Hitchcock : Reference was made by Professors Brainard 

 and Seely to the work of their predecessors recorded in the geological report 

 of the state of Vermont. I was concerned in that, and I should like to ex- 

 plain a matter in reference to it, as I think perhaps the part we took is not 

 clearly understood. I was the assistant appointed for that portion of the 

 state at the very beginning of my scientific career, going directly from Pro- 

 fessor Seely's recitation room. With the limited means at our disposal we 

 made no effort to study these rocks thoroughly. We practically followed 

 through the Champlaiu valley the results of 'Adams and Thompson, who 

 preceded us, and therefore we did not see the great thickness of limestone 

 that is represented by these sections. 



But there is another part of our work that I venture to take into account. 

 When we examined the limestones further east, which were called Taconic, 

 we came to the conclusion that they were practically the same thing as these 

 limestones directly on Lake Champlain, but we could not correlate them 

 because their thickness was so much greater, and therefore we gave to them 

 a special name — the Eolian limestone. The section of the Eolian limestone 

 corresponds with that given by the authors of this paper, being 2,000 feet in 

 thickness. The area in Shoreham was colored on our map as the Eolian 

 limestone, and thus we were in accord with these later conclusions, although 

 we used a different name. 



