ALABASTER AND CAVERNS OF BARNUKOVA. 
167 
limestone or inferior rocks, whether in Russia or in the west of Europe, is, toge- 
ther with the presence of Saui'ians, a good zoological reason for distinguishing 
the Permian system from all accumulations of higher antiquity. 
Among the other fossils of Itshalki, the Modiolse are so abundant, that the rock 
might be called “ Modiola Limestone,” and it is of great interest to observe, that 
the dominant species so closely approaches to one which occurs near Sunderland, 
that the only difference is in the lesser size of the English specimen. The Re- 
tepores are also abundant, and are all but identical with the R. Jlustracea of the 
English Magnesian Limestone. A smooth Terebratula near to T. elongata (Schlot- 
heim), a Turritella, and a little Natica, very much resembling the N. variata (Phill.), 
are also found here. 
Between Itshalki and Barnukova, and on the opposite bank of the Piana, is 
the little village of Kniaspavlova, near which are hillocks of white gypsum and 
limestone, containing the small Productus Cancrini, with Avicula, Terebratula elon- 
gata, Retepores, &c. In ascending the stream the masses of white gypsum expand 
considerably, as you approach Barnukova, where they form a cliff not less than 
eighty feet high 1 . The succession of the strata is precisely similar, however, to 
that of Arzamas. The caverns in this fine mass of alabaster have been accurately 
described by Pallas and Strangways. Though larger, they are, as before said, 
alike in kind to those upon the Ik, and similar cavities will be mentioned in the 
next chapter near Pinega, in the government of Archangel. They have always 
excited the curiosity of the inhabitants and attracted the attention of naturalists, 
but notwithstanding their celebrity, no one had attempted to define the geolo- 
gical age of the rocks in which they occur, before the period of our visit. The 
gypsum, in its pure white and saccharoid condition, appears to have a great de- 
velopment at this place, for besides the vertical wall of seventy or eighty feet, 
the spacious caverns which have been opened out in it do not reach to the ex- 
tremity of the great concretion. In a word, this rock of alabaster is identical 
with masses in other parts of Russia, and also with those of the same age on 
the south-eastern and southern flanks of the Iiartz. It is covered by a calcareous 
breccia inclosing angular fragments of a reddish limestone, and this bed is fol- 
lowed by others, of friable marly limestone filled with shells, particularly Modiolse 
and Ostreae. 
i This cliff is a little distant from the river, and in the grounds of M. Kissileff, now the Imperial 
Charge d’affaires at Paris. 
z 2 
