260 Dr Hrezerr on the Limestone of Burdichouse, 
which greatly overtop the lacustrine deposits we have been con- 
templating. 
The uppermost strata of the coal-measures of Loanhead, 
comprise alternating beds of sandstone, argillaceous and bitumi- 
nous shale, along with ironstone bands, coal, and some little lime- 
stone ; the workable beds of coal, two to ten feet in thickness, be-. 
ing about twenty-five in number. 
By these beds numerous oscillatory movements are made 
known to us. Some of the alternations of sandstone, and argillace- 
ous shale, might have been induced by matter drifting from dif- 
ferent localities; and, of course, varying with such localities. 
But, in other instances, particularly where we find strata alter- 
nating with coal, we must refer the whole to corresponding oscilla- 
tions of the earth’s surface, by which a land covered with ferns 
and other plants has been submerged beneath a fresh-water lake, 
only to reappear ;—and only to be succeeded by other alternate 
submersions and emersions, incidental to the early history of our 
planet. 
SECTION X.—THE EFFECTS OF OSCILLATORY MOVEMENTS OF THE EARTH'S 
SURFACE, CONSIDERED IN REFERENCE TO THE ANCIENT VEGETATION AND 
ANIMALS DESCRIBED IN THE PRESENT MEMOIR. 
That these oscillatory movements of the earth’s surface must 
have caused corresponding changes in both vegetable and ani- 
mal life may be expected. M. Apoipure Bronenrarr has fre- 
quently made observations on the differences of such plants as 
occur in the lower and upper beds of the carboniferous group. 
And, in the present instance, the Sphenopteris affinis and some 
few other ferns are, I suspect, confined to the inferior strata of 
the Lothian coal-fields. 
With regard to the races of animals which inhabit waters, 
corresponding changes have been noticed. M. Acassiz has re- 
marked, that, in a suite of strata belonging to any given forma- 
tion, he has found few fish in a lower bed to agree as a whole 
