Association of American Geologists and Naturalists. 141 



the interval which has since elapsed, a copious mass of publications has 

 appeared, enlarging prodigiously our acquaintance with the exact geo- 

 graphical distribution of our strata, with their relationship to each other, 

 and to the rocks of Europe, and with their organic remains, and their 

 other contents. Many of these embody the results of years of previ- 

 ous systematic research, prosecuted in obedience to legislative enact- 

 ment in several of our states, while others are the fruits of individual 

 investigations, conducted by members of our Association, and others 

 again, the contributions of distinguished foreign geologists, liberally as- 

 sisted with materials by our own explorers. 



These publications consist chiefly of the printed volume of Transac- 

 tions of this Society, published about a year ago, the five large quarto 

 volumes on the Geology and IVIineralogy of the state of New York is- 

 sued by that state at intervals during the last two years ; also the first 

 Report on the Geological Survey of Connecticut, and those papers read 

 at our last annual meeting, which have appeared in the American Jour- 

 nal of Science and Arts, together with memoirs submitted to the Geo- 

 logical Society of London, by Owen, Lyell and Logan. 



By these reports and memoirs, our knowledge has been greatly en- 

 larged in relation to almost every class of our rocks and every period in 

 our geological chronology. Respecting the primary crystalline masses, 

 we have received most valuable additions to the details previously in 

 print, through the minute description of Connecticut by Dr. Percival, the 

 interesting and instructive account of the district between the St. Law- 

 rence and Lake Champlain, by Prof. Emmons, and that of the southern 

 counties of New York by Prof Mather. We have also been presented 

 with an interesting article on Tin veins in New Hampshire by Dr. C. T. 

 Jackson. 



Concerning the Palceozoic strata of the United States, the publications 

 have been of an interest commensurate with the magnitude and gran- 

 deur of the formations. Besides the accounts already given of the range 

 of these rocks in New England ; principally by Hitchcock and Jackson : 

 a thorough and minute analysis of these as developed throughout the 

 wide state of New York, has been furnished by Emmons, Hall, Mather 

 and Vanuxem in their respective reports on the survey of that state. 

 The identity of some of the western strata with those of New York, is 

 well set forth in a memoir by Mr. Hall published in our volume of 

 Transactions, while a valuable contribution has been made to the geol- 

 ogy of the western states, by Dr. Owen in a paper on that subject, read 

 to the Geological Society of London. The extension of some of the 



