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stone; the latter formation (in great part resembling in mineral 
condition a Tertiary deposit of white limestone) may be said to range 
from Moscow to Archangel, and even into the country of the Sa- 
moides, preserving the same lithological and geological characters, 
and occurring almost universally in horizontal unbroken masses for 
the distance of nearly one thousand miles. Thus the examination 
of Russia has not only confirmed the paleeozoic classification of the 
Carboniferous, Devonian, and Silurian systems, but has given new 
materials for the establishment of correct geological theories as to 
the formation of the surface of the globe; for we now learn that 
deposits of this high antiquity have been left in undisturbed posi- 
tions over very large areas, and that under such circumstances 
their structure has undergone little or no modification; whilst the 
large Producti of our Mountain-lmestone occur in Russia in a 
white deposit, resembling the most incoherent parts of the Cal- 
caire grossier of Paris. The general results and details of this im- 
portant examination of Russia will shortly be brought before our 
Society. 
DEVONIAN SYSTEM. 
After reviewing the vast European extent which the equivalents 
of the Old red sandstone have been shown to occupy on the Conti- 
nent, we cannot forget how much we owe to the sagacious and 
exact researches of Mr. Lonsdale, set forth in his most masterly 
and highly scientific communication to us respecting the age of the 
limestones of South Devon, wherein, after showing the state of for- 
mer erroneous and inconsistent opinions upon the subject, he de 
tails the steps that led him to infer from zoological evidence alone, 
that they were of an intermediate age between the Carboniferous 
and Silurian rocks. 
Mr. John Phillips had already observed the resemblance between 
many of these Devonian shells and those of the Mountain-limestone, 
and Mr. De la Beche had long ago noticed the position of the Tor- 
bay limestones to be incumbent on strata of Old red sandstone ; and 
in 1839 suggested that their organic remains would seem to indi- 
eate relations to this formation. The cause of the obscurity that 
overhung this subject arose partly from the absence of any evidence 
from superposition, in consequence of the insulated place which 
these rocks occupied in the south of Devon; and partly from the 
non-existence, until a recent period, of any extensive catalogues of 
the organic remains of the Mountain-limestone and Silurian systems 
with which these fossils of South Devon might be compared. 
In 1837 Mr. Lonsdale had ascertained, from an extensive colla- 
tion of the shells and corals of the south of Devon with those of the 
Silurian system supplied in the catalogue of Mr. Murchison, and 
of the Carboniferous system in that of Mr. J. Phillips, that a large — 
proportion of the Devonian fossils presented a character interme- 
diate between those of the formations which lie above and below 
the Old red sandstone; and therefore concluded that the strata in 
which they are found must be subordinate parts of this intermediate 
