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The Taconic and Lower Silurian Kocks of Vermont and 

 Canada. By Jules Marcou. 



At the meeting of Oct. 17, 1860, I had the honor to read before the 

 Society extracts from three letters of M. Barrande, relating to the 

 stratigraphical position of the primordial fauna in North America. 

 Two of those letters were addressed to me, the third was a copy of a 

 letter to Professor Bronn of Heidelberg. I added a few remarks, and 

 the whole was published in the Proceedings, Yol. vii. p. 369, under the 

 title, '•''On tJie Primordial Fauna and, the Taconic System, by Joachim 

 Barrande, with additional notes by Jules Marcou." 



The views there exposed were received with little favor, at first, by 

 those geologists who, for the last fifteen years, have refused to recog- 

 nize the Taconic system, on the ground that it was not sustained by 

 any stratigraphical, paleontological, or lithological evidence. It was 

 hard for them to admit that the paleontological character at least was 

 against them, some going so far even as to deny the validity of pale- 

 ontological evidence in determining the age of strata. As the same 

 persons have long considered the lithological character " entirely 

 valueless," American geology was deprived of its two best supports, 

 and left entirely at the mercy of suppositions and conjectures. It was 

 evident, however, that the summary method, so frequently used, of 

 suppressing observations which did not agree with the views of those 

 regarded by some as the best and highest authorities on this continent, 

 could not succeed now, as it was impossible to rule out the science of 

 paleontology and its supporters. 



Three months later, Mr. Logan of Montreal, in a letter to M. 

 Barrande (in which he inadvertently omitted to mention our Boston 

 pamphlet), admits that the views entertained by him on the rocks of 

 Point Levi and Georgia were erroneous, and tries to explain the 

 position of strata at Point Levi, putting together all the rocks found 

 there, as the " Quebec group of rocks." 



Mr. James Hall, of Albany, in a letter to the editor of Silliman's 

 Journal, one month later, takes up the paleontological evidence, 

 letting it be understood that, if any mistake was made, it was due to 

 stratigraphy ; and mixing together, even more than Mr. Logan had 

 done, all the fossils found in the various places and strata at Point 

 Levi, he comes to the conclusion that " M. Barrande's plan of succes- 

 sive Trilobitic faunae " does not meet the case in hand ; and, without 

 giving any decisive opinion, he evidently leans toward the view that 

 he has always entertained, in common with the Professors Rogers, of 

 the Hudson River group. 



This letter of Mr. James Hall appeared in Silliman's Journal of 

 March, 1861, together with a reprint of Mr. Logan's letter, and also a 



