Barrande and the Taconic System — Marcou. 133 
strong basis that it can noAv stand all attacks. Mr. Dana to 
thwart as much as he could its effect, has written a letter to 
the Honorary President von Dechen, of the "Congres Geologi- 
que international," at Berlin, in 1885. The volume of "Compte- 
rendu," issued only in September, 1888, contains that letter at 
pp. cxx and cxxi; it shows some new ''leaps in the dark" even 
more startling than those we are accustomed to. For instance, 
he says: (1) "The Taconic rocks, or those of the Taconic range 
* * are of Lower Silurian age, none of them older than the 
Potsdam sandstone of the New York series. (2) There is no 
horizon of unconformability at any place in the series between 
the quartzites representing the Potsdam sandstone and the top 
of the Lower Silurian. These results are based on long-con- 
tinued stratigraphical investigations, and also on the existence 
of fossils in portions of the rocks where least metamorphosed." 
Against those clear and short results and conclusions, taken 
even in the "light" used by one of the association of the adver- 
saries of the Taconic there is a margin of eighteen thousand 
feet of strata containing primordial fossils, confronting Mr. 
Dana. For Mr. Walcott regards the Georgia formation, four- 
teen thousand feet or more of strata, and the "eastern quartzites" 
two thousand or more feet thick, as being all below the Potsdam 
sandstone of the New York series. Mr. Walcott's* researches 
have been made in the original Taconic area of the Taconic 
range of mountains and of Washington county, and his views 
express the "result of the accuracy of his original observations." 
Eighteen thousand feet of strata form a very respectable sys- 
tem, thicker and more important than any recorded in the 
general nomenclature of American geology; for according to 
Dr. Emmons' estimate the three superior systems above his Ta- 
conic; that is to say the Champlain system, or true Cambrian, 
the Silurian system and the Devonian system, all three together 
have only a thickness of eight thousand feet. Eighteen thous- 
and feet of Taconic strata according to Mr. Walcott, in the 
* Mr. Walcott has not yet recognized the two most important groups of 
the uoper part of the Taconic : the Phillipsburgh and Pointe L6vis group 
and the S wanton and Citadel hill group, which he continues to refer to as 
the equivalent and the homotaxis of the Calciferous, Trenton and Hudson 
of the state of New York. It is the last hope and a forlorn hope, which 
will be made use of with the tenacity peculiar to the not "elevated minded" 
adversaries of the Taconic system. 
