204 
MIOCENE PERIOD. 
[Cb. XV. 
terrestrial quadrupeds belong to the genera Mastodon, Rhino- 
ceros, Hippopotamus, &c, the assemblage, considered as a 
whole, being \evy distinct from those of the Paris gypsum. 
I examined several detached patches of the Touraine beds, 
where they rest on primary strata in the environs of Nantes, 
particularly one locality at Les Cleons, about eight miles south- 
east of that town, and was struck with the evidence afforded by 
them of the emergence of large intervening tracts of granitic 
schist since the Miocene era, which we might otherwise have 
supposed to have been raised at a very remote epoch. It is 
probable that these patches of tertiary deposits were originally 
local, having been thrown down wherever the set of the tides 
and currents permitted an accumulation to take place. 
The faluns and contemporary strata of the basin of the Loire 
may be considered generally as having been formed in a shallow 
sea, into which a river, flowing perhaps from some of the lands 
now drained by the Loire, introduced from time to time flu- 
viatile shells, wood, and the bones of quadrupeds, which may 
have been washed down during floods. Some of these bones 
have precisely the same black colour as those found in the 
peaty shell-marl of Scotland ; and we might imagine them to 
have been dyed black in Miocene peat which was swept down 
into the sea during the waste of cliffs, did we not find the 
remains of cetacea in the same strata, bones, for example, of 
the lamantine, morse, sea-calf, and dolphin, having precisely 
the same colour. 
Comparison of the Faluns of the Loire and the English 
Crag. — The resemblance which M. Desnoyers has pointed out 
as existing between the English crag and the French faluns 
is one which ought by no means to induce us to ascribe a con- 
temporaneous origin to these two groups, but merely a simi- 
larity of geographical circumstances at the respective periods 
when each was deposited. In every age, where there is land 
and sea, there must be shores, shallow estuaries, and rivers ; 
and near the sea-coasts banks of marine shells and corals may 
accumulate. It must also be expected that rivers will drift in 
