The Taconic — Marcou. 8i 
.covered by Primordial; but all the other half referred to the 
Champlain system is erroneous, except Larabee Point (lake 
Champlain,) and a few spots in the western part of Washing- 
ton county. 
The part of the map colored from field-work made by Mr. 
Walcott in 1883 — 84, in Franklin county, is not only at variance 
with what exists there but even with his own section published 
in 1886 (^Bullet hi U. 6"., Geol. Sur.^ No. 30,/. 16. At his 
Parker's section, Georgia, he has placed a large band of "Hudson 
River formation" on the shore of lake Champlain; on the map 
the Hudson is replaced by his middle part of Georgia, called 
limestone [red sandrock]. The shales of his No 2, which he 
regards as an "off-shore Potsdam sandstone deposit," are not 
distinguished on the map, being merged with the Georgia for- 
jnation. 
R^sumd — All Mr. Walcott's classification rests on the fol- 
lowing points. 
A. The quartzyte must be younger than the middle and 
Lower Georgia formation, and he regards it as the upper part 
of that formation without any stratigraphic proofs, only on the 
plea of a very few fossils which he interprets according to his 
present palaeontological tendency, and limited knowledge. 
B. The Potsdam formation being placed by him directly 
above the Georgia, in order to suppress the six thousand feet of 
the Phillipsburgh and Pointe Levis group, and the S wanton 
and Citadelle Hill of Quebec slates, Mr. Walcott makes extra 
efforts to find it somewhere in direct contact and superposition 
over the Georgia. Not being able to find the true .Potsdam 
sandstone, which exists close by — only a couple of miles off, 
on the edge of the Adirondack mountains, he has recourse to a 
^'belt of shales" which he assumes to represent the Potsdam 
sandstone, as an "off-shore deposit" contemporary with the true 
Potsdam. But even that assumption, contrary to all the char- 
acters of stratigraphy, lithology and palaeontology, that belt of 
shales is not suflficient; and in Dutchess county he has recourse 
to a limestone. However it is not yet enough, for to the east of 
this supposed Potsdam limestone, he says that the Potsdam 
"may be represented in part by either [ i ] the upper part of the 
•Quartzyte No. 1, [2] the lower part of thejimestone No. 3,orr3] 
