1887] The Taconic Question Restated. 239 
opinion expressed in 1842, that the whole Taconic system was 
“inferior to the Potsdam sandstone,” and repeated, in 1844, 
that “the Taconic system occupies a position inferior to the 
Champlain division of the New York system, or the lower 
division of the Silurian of Mr. Murchison.” In support of this 
view he attempts, in 1844, to show that both the Potsdam sand- 
stone and the Calciferous Sand-rock are found, the latter at inter- 
vals to the east of the valley of the Hudson, reposing upon the 
slates of the Taconic system, but adds, “probably, however, 
upon the Magnesian slates,” which, as we have seen (§ 12), were 
assigned by him to a horizon below the group called by him dis- 
tinctively the “ Taconic slates,” and were subsequently included 
in his Lower Taconic, the latter being Upper Taconic. In the 
same volume, in a subsequent chapter, which first appeared in 
1846, or two years later, he had, however, arrived at the conclu- 
sion that the Calciferous Sand-rock to the eastward becomes more 
largely developed, and, losing the distinctive character which 
had given that name to the west of Lake Champlain, becomes, 
to use the expression of Emmons, “ protean” in its modifications. 
Among these he now included the red sandstones of Addison, 
Charlotte, and Burlington, Vermont, with their interstratified red 
and chocolate-colored slates, besides blue limestones and gray 
calcareous sandstones, the whole resting upon what were desig- 
nated as black Taconic slates. These so-called protean modifi- 
cations of the Calciferous Sand-rock were now described by 
` Emmons as forming an irregular belt from Canada through 
Eastern Vermont, thence traversing Washington, Rensselaer, 
Columbia, and Dutchess Counties, and crossing the Hudson into 
Orange County. This series, more or less interrupted in its 
geographical distribution, but including areas of some miles in 
extent, is described as “ often forming the highest points in the 
_ region,” and Emmons remarks, “ We can hardly avoid the con- 
clusion that this belt was once continuous, and formed an impor- 
tant mass overlying the Taconic slate.” * 
§ 16. It is scarcely necessary to remark that this great belt of 
sandstones, slates, and limestones, now described by Emmons, in 
1846, as belonging to the Calciferous Sand-rock, and as resting 
on Taconic slates from Canada to Orange County, N. Y., is no 
other than the First or Transition Graywacke which, with the 
t Agriculture of New York, vol. i. pp. 118-122. 5 
* 
