Hitchcock.] 
36 
[May 16, 
a part of the Georgia group. I think any geologist will note a 
close agreement between the positions taken by the Vermont re- 
port and Mr. Walcott, save in the addition of the red rock to the 
slate group and the adoption of the theory of the fault. Walcott’s 
section is much larger and more detailed than mine in St. Albans 
a few miles north, but their similarity to each other is obvious. I 
think I may reasonably claim that the essential points of my defi- 
nition of the Georgia rocks have been accepted by the later ex- 
plorer to the detriment of those of Mr. Marcou. 
In reference to the reprint of Mr. Billings’ paper, Mr. Marcou 
remarks as follows : “Besides Mr. C. H. Hitchcock has suppressed, 
without any notice, a whole page of Billings’ paper, a very inter- 
esting foot-note pp. 11 and 12, containing among other informa- 
tion a letter from C. H. Hitchcock himself.” If Mr. Marcou will 
consult the volume entitled Paleozoic Fossils, Vol. I of the Can- 
ada Survey, where the pamphlet which afforded the descriptions 
copied into the Vermont has been reprinted, he will discover that 
Mr. Billings has also suppressed this foot-note. Perhaps it will ap- 
pear in the next memoir upon the Taconic rocks, that Mr. C. H. 
Hitchcock suppressed this foot-note in the Canadian volume ! It 
will be a favor to me if Mr. Marcou will furnish the proof that I had 
any concern in the omission of this page in the Vermont reprint. 
I have time for only one more topic. Of my exposition of the 
Taconic system, p. 434, Vermont Kept., where I attempted to por- 
tray truthfully the views of Professor Emmons, it is said by Mr. 
Marcou, “This brief view of its history as a system is full of reti- 
cence and even opposition, and is simply an ex parte and partial 
exposition,” etc. 
Others have thought differently. The Vermont report has been 
stated to be an advocate of the Taconic system because of the 
presence in it of that chapter. But whatever its imperfections, I 
am prepared to submit to any impartial jury the claim that my 
sketch is a more truthful expose of the Taconic System of Bmmons 
than are the writings of Jules Marcou. There is nothing more em- 
phatic than the insistence of Professor Emmons upon the uncon - 
formable superposition of the Silurian Potsdam sandstone above the 
Taconic system . Professor Emmons prided himself upon having 
discovered and defined this sandstone, which constituted the base 
of the Silurian system in this country. It is my belief that he 
