38 The American Geologist. January, 18I.7 
So according to the author of the palfeontological rule for 
deteniiining and classifying strata, it must be used with a 
great deal of care, and much attention must always be paid 
to similar forms of fossils and even tf> a few identical species 
which enjoy the privilege to survive their contemporaries. 
Finally the horizontal distances or climats, as Brongniart 
says, exert an influence which ought to be carefully weighed. 
Let us see how those rules have been applied in the classi- 
fication of strata in North America and point out the misrules 
made which have kept back so persistentl}^ the progress of 
American geology. 
Classification of the Niagara gkouf with the Old Red 
Sandstone. 
The tirst important misrule in America is found in the 
Second Annual i^ejoor/". Geological Survey of New York, p. 
291, Albany, 1838, where the author of the report of the fourth 
geological district, after classifying the Niagara group with 
the Old Red sandstone of Europe, says : "The evidence for 
this conclusion rests, in part, upon the organic remains, and 
if we can rely on these characters there appears little ques- 
tion regarding the age and position of our rocks " So. ac- 
cording to the writer of the report, the Niagara group is to be 
classified as being above the Silurian system of Murchison, 
instead of being the main and central part of the Upper, or 
true Silurian, an erroneous correlation and classification due 
to palaeontological mistake. 
Classification of the Taconic System with the Hudson 
River group. 
The second misrule by the same writer is even more impor- 
tant, for it suppressed a whole system, the greatest in regard 
to thickness of strata — about 25,000 feet — and the first link 
in the great chain of fossil remains which have existed on 
our globe. Here the mistake was made by the wrong deter- 
mination of fossils, mainh' trilobites, and a no less erroneous 
idea of wrong stratigraphy and wrong lithology, almost in- 
credible, for it was made not only against all the rules of 
stratigraphic classification, but against an exact description 
and classification of those strata made by the Strata Smith 
and Alex. Brongniart of North America, the late Dr. Eben- 
ezer P^mmons. mMio had called them the Taconic .system, con- 
