South-west and North of France , and North of Germany. 147 
stone, which exists itself at Lichtensteig, and between Solothurn 
and Aarau ; and, besides, in the southern part of Switzerland, 
there are marls with gypsum, which seem of a later date than 
the molasse. Compared with the Austrian and Hungarian ter- 
tiary basin, this deposit appears of the same nature only in its 
lower part, for the whole of the remaining parts of the deposit 
are wanting in Bavaria. 
The classification of the Austrian deposits has proved a mat- 
ter of much perplexity to those geologists who pay too great at- 
tention to petrifactions ; and they will be much astonished 
when they are informed, that, in the chalk, or perhaps newer J ura 
limestone of the Leithagebirge, there exist imbedded (not 
in veins ) bones of the mastodon. Nature often overturns 
the most beautiful systems ! Above this chalky deposit, alter- 
nating with some beds of arenaceous rocks or calcareous nagel- 
fluhs, lies the plastic clay, with lignites and fresh-water shells ; 
then comes the blue clay, with marine shells and bones of qua- 
drupeds, as in the plastic cl&y, and which is as analogous 
to the coarse marine limestone of Paris, as to the London clay. 
Above it, are some clay marls, with impressions of leaves belong- 
ing to genera of trees still existing in the country ; then sand 
without or with marine shells, and some few melanopsides , indi- 
cating a similarity to the Montmartre fresh-water gypsum depo- 
sit ; and after that, sand, marl, and marine coarse limestone, cor- 
responding to the upper marine sand of Paris, and fresh-water 
spring deposits here and there upon hillocks (see Prevost). 
Geologists, who classify this deposit in a different manner, be- 
cause bones of quadrupeds are only found at Paris above it, 
commit the same error as those observers who take a ^niall cor- 
ner of the earth for an immutable geological type. Each parti- 
cular basin has its own peculiarities : this is an axiom in transi- 
tion, in secondary, and still more in tertiary deposits. 
I intend to finish this memoir by a view of the changes 
which have taken place in the waters of the Bavarian basin. 
The following are the conclusions at which I have arrived. 
That country formed, at one time, with Switzerland, the Bhine- 
Valley, and Austria, part of the immense sea which communicated 
with the Northern Sea, and the Mediterranean. After the depo- 
sition of the chalk formation, this sea became an inland sea, and 
k 2 
