we 
694 Notes on Classification and Nomenclature. [Ang 
which was erected by Mr. Emmons, including formations that 
extended eastward into Massachusetts and Vermont, and west | 
ward to the Hudson River, covering a series of strata from the | 
gabbros of the Adirondacks to the top of the Lorraine shales, 
has been overthrown by the researches of Dana and his col- 
leagues,—in other words, that the “Taconic System,” as con- 
structed by Dr. Emmons, cannot be maintained. 
On the other hand, the Taconic rocks, in which Emmons f 
found primordial fossils, and to which he extended the name f 
which he applied to his system, have been found to have a wide f 
extension and a great thickness, as well as a characteristic fauna 
` The initial point of divergence between him and his colleagues 
on the New York survey was as to the existence of such pre 
Potsdam strata. From this initial point he built up a system 
without warrant. He laid a true foundation, but his super 
structure was not well built. In consequence of a poor supèr 
structure, the tendency has been strong to sweep away also his 
foundation, denying to both of them the right to existence it 
geological nomenclature. 
The question that comes before this committee is to determint 
by what designation the strata shall be known that contain thè 
foundation-rocks of the “ Taconic System” of Emmons,—thos 
that really are stratigraphically pre-Potsdam. | 
Recent palzontological researches and work in the field show 
that the pre-Potsdam fauna pervades a belt of rocks that extends 
from Northern Vermont southward, by way of Georgia, ve" 
mont, Bald Mountain, New York, Schodack Landing, to Stock l 
port, Columbia County, east of the Hudson River, comprising 
a thickness of strata amounting to about four thousand feet. 7 
is also reasonable to suppose that it constitutes the basal portion 
of the range of the Taconic Mountains, and perhaps a large par 
of the range in some places. It is therefore not inappropriate bad 
consider the claim of Dr. Emmons to give name to this belt 
(a) Taconic versus PRIMORDIAL. 
The term primordial, adopted by Barrande for the first faun® 
is more comprehensive than the fauna that was discoveree by 
Emmons in these Taconic strata. But Barrande distinctly & 
knowledges that Dr. Emmons antedated him in the discov 
and advocacy of a fossil horizon belonging in the primom’™ 
