Geology of the Environs of Petersburg . 
453 
south by a red sandy country resembling that on the north west of 
the Volkhof ; it appears to pass by Chudovo, and to bound the plain 
of Novgorod and Ilmen. I have seen specimens of it from Seltza 
Posad on the Shelon, in the government of Pscov : but I cannot 
state with certainty whether that forms a detached body from the 
great mass of the formation to the north, or whether it is connected 
with it. In character it resembles that of Esthonia. 
Westward, the limestone stretches along the boundary of 
Esthonia and Livonia, occupying the greatest part of the former 
country. Near Fellin in Livonia, it is said to have been worked 
formerly by the Swedes, for the sake of lead and copper, no longer 
to be found there. It is continued to the western extremity of 
Esthonia, and passes into the group of islands of which Oesel and 
Dago are the principal, and in which some of its beds are sufficiently 
fine to be used as marble. This Esthonian portion of the limestone 
is famous for the superior beauty of its organic remains, especially 
at Lachsberg, near Reval. They agree with those found near 
Petersburg, but the fungites and corallines are larger and in a much 
better state of preservation. Boulders of it are found scattered over 
the central parts of Livonia, and more sparingly in the vale of 
Novgorod. It is connected with the Ingrian limestone by passing 
between the Lake Peipus and the gulf, and under the stream of the 
Narova, being the rock over whose strata that river falls a little 
above Narva. 
I have above only followed this formation as far as it is known 
with tolerable certainty to extend in one uniform direction, and in 
a mass probably but little interrupted, within the confines of Russia; 
an investigation which at the same time will serve to give an idea of 
what must be its boundaries along a part of the northern and eastern 
borders of the Great Basin of the north. Before I am led to speak 
