214 Tlie American Geologist. April, isoo. 
who placed the Sillery at the summit and the Levis at the 
base, whereas the true succession shows the Sillery at the 
base, followed comforraably by the Lauzon, the Levis being 
at the summit. 
Jt. The name of the Quebec group should be rejected in 
geology. 
To all of these propositions I assent most heartily, the more 
so that I have maintained them nearly twenty years, for the 
most part single-handed, and on every favorable occasion. 
A slight acquaintance with the history of geological opinion 
as to the crystalline rocks of the Green Mountain range and 
their relations to the adjacent uncrystalline sediments 
would have shown our authors that the views advanced 
concerning these two classes of rocks were not simply 
those of "Logan and his adherents," but of the majority of 
American geologists for the past fifty years. Amos Eaton and 
Ebenezer Emmons had, it is true, taught that the region of 
crystalline rocks in question constitutes an ancient anticlinal 
axis, and that the uncrystalline sediments along its northern 
and western base were deposited unconformably upon these 
old rocks and were in part made up of their ruins. The doc- 
trine of regional metamorphism, then and since carried to great 
lengths both in Europe and in America, was, however, adopted 
by Mather ; whose large quarto volume on the geology of the 
Southeastern District of New York, published in 1843, was at 
once generally accepted as authority, so far as New York and 
western New England were concerned. The continued east- 
ward dips observed in the paleozoic strata east of the Hudson 
and the supposed gradual transition of the uncrystalline sedi- 
ments into cr3'stalline schists led Mather to assert that these 
latter were nothing else than the upper portion of the Cham- 
plain division of the New York paleozoic series, or the so-called 
Hudson slates in an altered condition. This view was cited 
with approbation in 1844 by H. D. Rogers, who, in company 
with his brother, W. B. Rogers, attempted to show in 1846 that 
the gneisses and mica-schists of the White Mountain belt, ly- 
ing to the east of the Green mountains, were still newer rocks, 
and represented probably the horizon of the Oneida, Medina 
and Clinton of the New York series. Chas. T. Jackson moreover 
in his volume on the geology of New Hampshire, in 1846, while 
he declared that the White mountains constitute an axis of the 
