112 COAL OF LISSITCHIA-BALKA SUBORDINATE TO CENTRAL LIMESTONE. 
Pecten and Nautilus. In the limestone and slate-clay above the splent coal, the 
Spirifer Mosquensis is again seen, associated with a Pecten, a Retepora and other 
flexible Polypifers ; and lastly, in the limestone overlying the lowest coal, this 
shell is again found, together with the Euomphalus Baeri, n. s. (Eichw.). 
Of the plants we have not the means of speaking with the same precision, not 
having brought away good specimens ; but we are certain that many of the forms 
of Equiseti, Calamites, Sigillaria and Ferns which we saw are identical with species 
common to the coal formations of Western Europe. 
The section of Lissitchia-Balka proves to us, that in a vertical depth of near 
900 English feet, the united thickness of the coal-seams is upwards of thirty feet ; 
of the limestones, near fifty ; of the grits and sandstones, above 200 ; whilst the 
argillaceous beds, which vary in quality from the clunch to the clod of the miners 
(or slate-clay, schist, shale of the mineralogist), amount to near 600 feet. 
These lithological statistics are of theoretical as well as of practical value, for 
they enable us to speculate on the conditions under which the coal was accumu- 
lated, whilst they teach us how, with varying lithological and organic contents, 
the same beds, in different parts of the globe, assume such very different aspects. 
Seeing the argillaceous schists, shale, sandstone and grit, which here alternate 
with the coal, and the frequency and dimensions of the coal-seams, any practical 
collier from the best-worked tracts, even of the British Isles, who had not studied 
fossil remains, might be convinced that these shafts were sunk in the coal- 
measures, the “ Terrain Houiller ” of the French ; and still more closely would he 
cling to this belief, when he saw that the forms of the plants were identical with 
those to which he had been accustomed in his own coal-fields, imbedded in similar 
clod, clunch, sandstone and grit. Yet would he have erred in classification, to 
the extent of one great and important member of the geological scale, for the bands 
of limestone and calcareous shale which alternate with this great argillo- carbon- 
aceous mass, inform us without any doubt, that all these accumulations (unlike 
those of our upper coal-fields, in which marine exuviae are either absent or ex- 
ceedingly rare,) were deposited under the sea. From the top to the bottom of 
the section, we find unequivocal remains of marine animals, many being, indeed, 
identical with those which abound in the great limestone that forms the support of 
the coal-fields of the British Isles. In the western dales and moors of Yorkshire, 
Durham and Northumberland, there also exist, it is true, certain beds of coal in 
the lower or marine members of the Carboniferous system, but they are not by 
