170 
THE GEOLOGIST. 
seen. Numbers of these animals have been mired in the bogs^ 
and horses and cows have perished in like manner. Along with 
their remains are found innumerable bones of Mastodon, Ele- 
phant, and other extinct quadrupeds, which must have visited 
these springs when the valley was in its present geographical 
condition in almost every particular, and which must have been 
mired in them as existing quadrupeds are at present. The mas- 
todon remains are most numerous, and belong to individuals of 
all ages. The mud is very deep, black, and soft. In places it 
is seen to rest upon the limestone, and at some points it swells 
up to the height of several feet above the general level of the 
plain and of the river. It is occasionally covered by a deposit 
of yellow clay or loam, resembling the silt of the Ohio, which is 
from ten to twenty feet thick, rising to that height above the 
creek and often terminating abruptly at its edges. This loam 
has all the appearance of having been deposited tranquilly on 
the surface of the morass and of having afterwards suffered de- 
nudation. The Mastodon and other quadrupeds have been 
mired before the deposition of the incumbent silt, for a con- 
siderable number of fossil bones have been found by digging 
through it. Accompanying the bones are freshwater and land 
shells, most of which have been identified by Mr. Anthony with 
species now existing in the same region. 
Mr. Lyell observes that the surface of the bog is extremely 
uneven, and accounts for it partly by the unequal distribution 
of the incumbent alluvium which presses with a hea\y weight on 
certain parts of the morass, from which other portions of the 
surface are entirely free. He also attiibutes it in part to the 
swelling of the bog where it is fully satm-ated with water near 
the springs. 
The author is of opinion that the fossil remains of Bigboue 
Lick are much more modern than the deposition of the di'ift, 
which is not present in this district. But although the date of 
the imbedding of these mammalian fossil remains is so ex- 
