The two most interesting points in this connection were, that 

 there is no foundation for what Mr. Emmons called his Taconic 

 system, (a mixture of the Silurian and Devonian,) and that the 

 Dorset limestone (his Stockbridge limestone) is newer than the 

 lower Silurian, and is probably upper Silurian or Devonian. 



Prof. W. B. Rogers remarked upon the importance of the 

 investigations referred to by Mr. Hitchcock, and spoke of the 

 difficulty which the geologist has to encounter in attempting to 

 ascertain the precise sequence of the rocks in a region where, as 

 in the greater part of Vermont, perplexing structural features, 

 metamorphic influences, and an extreme paucity of fossils com- 

 bine to embarrass his inquiries. It is not therefore matter of 

 surprise that, in spite of repeated explorations, some important 

 problems in the geology of the State should still remain unre- 

 solved. 



As regards the belt of formations on the western side of the 

 State, extending along the shore of Lake Champlain, the abun- 

 dance of fossils and the almost undisturbed position of the strata 

 have rendered their investigation comparatively easy, so that 

 these formations were early identified with the lower members of 

 the paleozoic series, from the Potsdam sandstone to the Hudson 

 River group inclusive. Immediately eastward of this narrow 

 strip is another belt of variable breadth, extending through more 

 than half the length of the State, and passing northward into 

 Canada. This consists of reddish sandstones and shales, and red- 

 dish, white, and gray limestones, which, from lithological pecu- 

 liarities and the absence of distinct fossils, were much less easily 

 referred to their proper geological position. Indeed it is only 

 within a few years that this remarkable group of strata has been 

 generally recognized as belonging to the period of the Oneida 

 and Medina rocks, to which Mr. Hitchcock now refers them. 



As connected with the history of this investigation. Prof. Rog- 

 ers felt some satisfaction in stating that in a paper entitled 

 " Notes on the Geological Structure of Western Vermont, &c.," 

 communicated by him to the American Association at Albany in 

 1851, the manuscript of which he now submitted, he gave a de- 

 tailed account of numerous sections and longitudinal tracinojs 

 made during preceding seasons, and in express terms announced 



