48 
RED SANDSTONE OF V1TEGRA, THE ANDOMA, ETC. 
these hills are perpetually subsiding into under-cliffs, and the varied streaks pro- 
duced hy these subsidences, might induce any person who viewed them from the 
lake, to believe that the strata were inclined. This, however, is far from being the 
case for they deviate only from horizon tality in exhibiting slight undulations, or 
hy rising very slightly to the north-north-west. Among the rolled fragments which 
cover the shore of the lake, near the mouth of the Andoma, are numerous masses 
of red rock loaded with remains of ichthyolites, chiefly Holoptychius (?), which, 
being of a much harder nature than the surrounding strata, have probably been 
derived from the cliffs which lie to the north, where the sandstone has undergone 
more consolidation and alteration. 
In ascending the banks of the Andoma and those of its tributaries, the Nosreka, 
&c., the place of the rocks which constitute the lower or red region is distinctly 
seen. All the plateaus or high grounds are there occupied by the carboniferous 
limestone and its associated bands of bituminous schist and yellow sandstone. The 
annexed woodcut represents the general relations of this instructive and pictu- 
resque district, in which we made excursions through some of the finest and most 
accessible of the Russian forests. The beds marked a and b are the Devonian rocks, 
and they are overlaid by the carboniferous strata c, d, e, to be described in the next 
chapter. 
8 . 
The lowest beds ( a ) are light brownish red, siliceous sandstones, occasionally flag- 
like, and sometimes of concretionary form, in which (on the banks of the Nosreka) 
we found disseminated bones and scales of ichthyolites. The strata b consist of a 
great thickness of red and green spotted argillaceous marls, with some sand, &c. 
In no part of this extensive district of red sandstone around Yitegra, and which oc- 
cupies the banks of the Lake Onega, and of which such deep denudations are exposed 
on the banks of its tributary streams, did we observe a single course of limestone, 
and with this absence ol calcareous matter, we no longer tound the mollusks ot 
the same age, which abound in Livonia, St. Petersburgh, and Novogorod ; fossil 
fishes alone being, as far as we could observe, the inhabitants ot these sandy and 
argillaceous rocks. We shall presently draw attention to this phenomenon in our 
remarks upon the distribution of the organic remains ol this system. 
