128 The American Geologist. February, is97 
then), under the name of "Oneota." Besides it wiis important 
to establish the correlations with the great stratigraphic sys- 
tems of Europe, a work so well done by De Verneuil in 1846. 
and which wanted to be transferred on the otlicial geological 
map of the state. 
The state geologist, Mr. James Hall, has followed closely 
the researches of Vanuxem, (Jonrad and De Verneuil, improv- 
ing by well observed details the stratigraphy of all the coun- 
try between Schenectady, Schoharie, BuH'alo, and the bound- 
ary line of the state of Pennsylvania, and his map of 1894 is 
a great improvement on the geology and geography of the 
third and fourth districts. So now, thanks to the Geological 
Survey of New York, and its director, Mr. James' Hall, we 
possess for that important portion of the state a correct and 
excellent geological map. 
But the other portions, especially the eastern, or first geolog- 
ical district, are still far from satisfactory, on the map of 1894. 
Dr. Ebenezer Emmons, on his geological map of 1844, with the 
approbation of Vanuxem, introduced a new great system of 
deposits of about 25.000 feet of strata, lying east of the Hud- 
son river and of lake (Jhamplain, which he proved by strati- 
graphy, paUeDntology and lithology to be older than the Lower 
Silurian or Ohamplain system, and which he called most 
appropriately the Taconic system. It was a stroke of genius 
on the part of Dr. Emmons, who, before any other geologist 
or any other country, found in America the true base of the 
sedimentary strata, the primordial fauna, and consequently 
the first and most important great geological period in the his- 
tory of the earth. 
Dr. Emmons did not color any of the divisions made by him 
in the Taconic, and he was satisfied to place the whole of it 
under a single color. The map of 1894 follows Emmons in 
using also a single color for the strata of the Taconic system, 
only it replaces the name Taconic by a name of a village of 
the state of Vermont, -Georgia" ; and almost two-thirds of the 
strata of the Taconic are cut off and placed farther up in the 
scale of formations, as we have seen and explained in the first 
part of this memoir. The Georgia group of Mr. Hall occu- 
pies, on his map, first, narrow lines in the southern part,, 
east of the Hudson river, then going northward the lines be- 
