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L. Lesquereux on the Coal Formations of North America. 27 
large surfaces, shows itself, along with the characteristic fossils of 
its shales, in every part of the measures where the thickness is 
sufficient to reach to its level. Thus we have some keds of coa 
the identical distribution of the coal beds and of the coal flora in 
both basins. it has been very courteously controverted in 
this Journal,* and especially as the diseussion of this geological 
point enters into our subject and may help to satisfy the min 
upon the value of the so-called new theory mentioned above, it 
is proper that I should briefly present the reasons in favor of my 
opinion. 
It would be absurd to assert that the veins of coal or rather 
that the peat bogs of the coal formations were formed on a per: 
fectly horizontal surface, and that the woody matter was deposi- 
ted in the same thickness over the entire area. The most even 
plains have undulations on their surface; and the cross-section 
given in my report of a part of the Dismal Swamp of Virginia, 
should have explained my meaning. The peat bogs of our time 
are more or less broken or crossed by small elevations of sand 
or hills of some other deposit, which here and there break their 
horizontality and also their uniformity of features. For, although 
these irregularities may be scarcely elevated above the surface of 
the bogs, they are without exception, covered with a vegetation 
of entirely a different character from that of the peat bogs, and 
therefore their outline is perfectly definite. Sometimes groups 
of islands are thus seen rising in the middle of the bogs. 
Sometimes,"also, as in the granitic country of the Hartz moun- 
tains, or in the basaltic. region of the Rhoen mountains of Ger- 
many, peaks of granite or columns of basalt protrude like towers 
from some parts of the swamp. Noone will contend that these 
irregularities break the continuity of a formation; or that the 
peat bogs on both sides of a hill of sand or around a block of 
granite are not a continuous formation. In a geological point of 
view, accidents like these cannot be taken into consideration. 
* This Journal, yol. xxvi, p. 78, July, 1853. 
