from a limestone of the original Taconic. 247 



But, more than this, the eastern and western limestones have 

 a surface connection. From New Lebanon the western con- 

 tinues northward, and three miles to the north (in Stephen- 

 town) it stretches on, in a north by east direction, into Massa- 

 chusetts, passing in a broad belt through the towns of Hancock 

 and Williamstown, as my Berkshire map, above alluded to, will 

 show, confirming Professor Hitchcock's map of 1841. Thence 

 it extends northward uninterruptedly into Vermont (as the Ver- 

 mont geological survey, and my own observations prove), and 

 becomes the great central marble belt of that State, passing 

 through Bennington, Dorset, Rutland, and to and beyond Mid- 

 dlebury. Thus the same Taconic limestone belt that contains 

 Trenton and Chazy fossils in Rutland, Vermont and towns 

 farther north, as shown by the Vermont Geological Survey, is 

 now proved to have Lower Silurian fossils west of the Taconic 

 range at Canaan in eastern New York. 



The reading of this paper at the meeting of the American As- 

 sociation was followed by remarks by Prof. James Hall and also 

 by Prof. N. H. Winchell. Prof. Hall observed rightly that the 

 conclusion as regards the Lower Silurian age of the Taconic rocks 

 was not new. This fact I have urged in all my papers on the 

 Taconic rocks except the present one; and I made it the special 

 point of the paper preceding this one, presented in 1882 to the 

 Geological Society of London, showing that the conclusion I held 

 had been sustained by every geologist who had investigated the 

 region and published on it since the Taconic system was first an- 

 nounced— W. B. and H. D. Rogers, W. W. Mather, E. and C. H. 

 Hitchcock, and A. Wing. In my Manual of Geology, the bibli- 

 ography of the Taconic system is given under the two heads of 

 authors sustaining its Lower Silurian age, and those not; and 

 among the former is the name of Prof. Hall. 



Unfortunately for the science, Prof. Hall, while one of the fore- 

 most to contest the conclusions of Prof. Emmons before the As- 

 sociation of Geologists and Naturalists in 1840 to 1845, published 

 nothing on the subject ; neither were his remarks before the As- 

 sociation published in its brief proceedings. Moreover, no paper 

 giving his later opinion has since appeared. In 1884 (September 

 13), 40 years after those discussions, I received from him (as a 

 sequel to a letter of enquiry as to any publications of his on the 

 subject) two plates of stratigraphical sections across the Tacpnic 

 region, prepared by him 40 to 45 years since, showing plainly 

 careful labor in the field with reference to settling the debated 

 question. This most welcome addition to the facts afforded proof 

 conclusive of the synclinal character of portions of the Taconic 

 range, as I have stated in a notice of them in volume xxviii (1884) 

 of this Journal (p. 311). 1 had also asked him in my letter his 

 opinion as to the age of the Hoosic Slates (40 miles north of Ca- 

 naan), from which Prof. Emmons and others, in his publications 

 later than 1842, had reported Graptolites, this point bearing 



