484 ADDRESS OF T. STERRY HUNT. 
other American geologists, maintained that the crystalline rocks 
of the Green Mountain and White Mountain series are altered 
paleozoic sediments, I find, on a careful examination of the evi- 
dence, no satisfactory proof of such an age and origin, but an 
array of facts which appear to me incompatible with the hitherto 
received view, and lead me to conclude that the whole of our crys- 
talline schists of eastern North America are not only pre-Silurian 
but pre-Cambrian in age. 
In what precedes, I have endeavored to discuss briefly and 
impartially some of the points in the history of the older rocks, 
and of the views which during the past thirty years have been 
entertained as to their age and geological relations, both in Amer- 
ica and in Europe. I have said some things which will provoke 
criticism, and at the same time, I trust, lead to farther study of 
‘these rocks, a correct knowledge of which lies at the basis of 
geological science. s 
I cannot, however, conclude this part of my subject without 
referring to the views put forth in 1869 by Professor Hermann 
Credner of Leipzig, in an essay on the Eozoic or pre-Silurian for- 
mations of North America.* With Macfarlane, he refers to the 
Huronian the gneissic series of the Green Mountains, but includes 
with it, as part of the Huronian system, the so-called Lower Ta- 
conic rocks of Vermont, ‘* with remains of annelids and erinoids.” 
Credner thus falls into the very error against which Emmons 
warned American geologists, namely, the confounding in one sy 
tem the ancient crystalline schists with the newer fossiliferous 
sediments. Resting unconformably on these, he places, first, the 
Upper Taconic, corresponding, according to him, to a part of the 
Quebec group, and second, the Potsdam sandstone. In this he 
has copied, for the most part, Marcou, who, however, groups the 
whole of these various divisions in the Taconic system, while 
Credner, rejecting the name, unites a portion of the Taconic of 
Emmons with the Huronian system, and refers the other portion, 
together with the Potsdam, to the Silurian. These same views are 
set forth in a more recent paper, by the same author, on the Alle- 
ghany system, which is accompanied with sections and a geologi- 
cally colored map.+ In this, not content with including in the 
Huronian both the fossiliferous strata of the Levis formation and 
* Die Gliederung der Eozoischen Formationsgruppe, u. 8. W., pp. 53. Halle, 1869. 
+Petermann’s Geographische Mittheilungen. 2 Heft, 1871. 
