, and another in Sardinia (_Molge Rusconii_). Again, in Algiers
there are two species, viz., _Molge Poireti_ and _M. Hagenmuelleri_,
while the Moroccan _M. Waltlii_ passes into the south of Spain. Here
_Molge boscae_, _M. aspera_, and _M. marmorata_ originated, the latter
passing into France.

Another branch of the _Molge_ tribe turned northward from Greece towards
the newly forming Alps; and there originated _Molge alpestris_ and _M.
palmata_, which more recently have spread into England (one at least),
Germany, France, Austria, and Southern Italy. _Molge vulgaris_ is an
Asiatic species which wandered northward after entering Europe, covering
a large area, but never reached the extreme south or south-west. _M.
cristata_--the large Water Newt--has a similar but not quite so extended
a range, while _M. vittata_ never managed to cross the borders of Asia
Minor. Some of the other species occur in China, Japan, and North
America.

None of the tailless Batrachians--the Frogs and Toads--are peculiar to
the Alps, but one, viz. _Rana temporaria_, ascends to the height of no
less than 10,000 feet. It is our common British Frog. No other Frog
probably ranges so far north or to such heights.

Let us now inquire what the invertebrate fauna of the Alps teaches us.
We are told by Dr. Kobelt, the great authority on European land shells,
that a uniformity of character marks the Alpine Molluscan fauna (_b_,
i., p. 251). One of the characteristic genera _Campylaea_--often looked
upon as a sub-genus of _Helix_--is a group containing somewhat flattened
conspicuous snails of large size. These are found everywhere in the
Alps, and wherever they occur beyond the confines of these mountains,
remarks Dr. Kobelt, their origin from the main stock is easily traced.
They have been gathered in the Apennines in Sicily, and even beyond the
Mediterranean in Algeria. On the Balkan peninsula they occur right down
to the most southern point of Greece, but are not met with either in
Crete or Asia Minor. One species has been found sub-fossil in Thuringia
in Northern Germany.

Another truly Alpine genus, says Dr. Kobelt, is the operculate
_Pomatias_, which in its geographical distribution offers some
interesting modifications from that of _Campylaea_. Less limited to high
elevations, it has spread over a greater part of the plains. This has
happened especially in France, while in Germany one species advances
almost as far north as Heidelberg. In other di