412 J. D. Dana—Taconie Rocks and Stratigraphy. 
Adding the discoveries in Canaan (Columbia County, New 
York), on the western side of the Taconic Range, to those of 
Vermont on the eastern side, and in Dutchess County to the 
south, the facts are enough to demonstrate the Lower Silu- 
rian age of the Taconic limestone, the eastern and western. A 
Cambrian limestone is in places included in the formation, and 
when so it is conformably to the other strata except where 
faults occur. Mr. Wing announced the limestone of Ver- 
mont to be a combination of limestones from Potsdam to Tren- 
ton inclusive; and Prof. Dwight has found the same to be true 
near Poughkeepsie. 
I have not felt at liberty to adduce as additional evidence to 
that from the Canaan limestone, the discovery of Lower 
Silurian fossils in the “Sparry ” limestone of Hoosac, thirty 
miles north of Canaan, which Prof. Hall stated, at the meeting 
of the American Association in 1885,* that he made more than 
forty years since, because Prof. Hall has never mentioned this 
discovery in any of his published writings, and has not yet 
announced the kinds of species or the particular locality. Science 
cannot rightly use the facts before these details are made known. 
The existence of fossils in the Hoosac limestone is not at all 
improbable. 
[To be continued. ] 
The Views of Prof. Emmons on the Taconic System. 
The announcement has been very recently made that Prof. Em- 
mons admitted that the age of the western (Sparry) T'aconic lime- 
stone was Lower Silurian in his second report on the Taconic 
System, that of 1844:—issued first in a quarto pamphlet, and in 
1846 incorporated with his Report on the Agriculture of New 
York. Since my writings on the subject will need some correction 
in case this is a right interpretation of his report, I have been 
again over his statements, and give here the result. 
The announcement appears in a paper by Dr. T. Sterry Hunt, in 
the February number (pp. 114-125) of the American Naturalist 
(issued near the close of March).t It is stated that Prof. Emmons 
in 1842, in his first detailed publication: on the Taconic system 
(Report on the Geology of New York, 1842), pronounced the 
Transition or Sparry limestone, like the rest of the Taconic, to be 
older than the lowest member of the New York Lower Silurian 
(or Champlain Division), but that in 1844, 1846, “he made one 
important and significant change,” “‘ acquiescing in the judgment of 
Eaton ” [‘of 1832] he “now declared that the upper portion of the 
Taconic system—namely, the great belt of slates with limestones, 
sandstones and conglomerates—designated by him in 1842 as the 
Taconic slate, and including both the Transition Greywacke and 
* This Journal, III, xxxi, 248, 1886. 
+ The title of the paper is, ‘‘The Taconic Question Restated.” 
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