ld probably now find many species in Northern
Russia, Germany, and France; but this is not the case, and we may
therefore assume with some justification that the Southern or Oriental
route was the only one available at the time when the bulk of the
species of _Nebria_ wandered to Europe. Many of the _Nebrias_ occur in
Switzerland and in the Alps, generally on the margins of the snow-fields
and glaciers, like _N. Germari_ and _Brunii_. Others, for example, _N.
atrata_, ascend to the highest limit of animal life, having been
observed at a height of over 10,000 feet.

Of the remaining orders of insects we know as yet very little. Central
Asia and even Siberia are only beginning to be explored, and their
invertebrate fauna--except _Lepidoptera_ and _Coleoptera_--is
practically unknown. However, I cannot conclude this short summary of
some of the more characteristic Alpine animals without referring to the
Grasshoppers which are so conspicuous in the mountains. The mountain air
simply rings during a bright summer's day with the loud and cheerful
song of millions of these insects. It is one of the most vivid
impressions a tourist brings back from Switzerland--this constant shrill
sound issuing from an apparently invisible source.

Among these Grasshoppers there are some highly characteristic Alpine
genera. _Pezotettix_--formerly known as _Podisma_--is one of these. _P.
alpinus_ is almost confined to the high Alps; with _P. mendax_ it occurs
in lower levels chiefly towards the south-east, that is to say, in the
direction of Hungary, Servia, and Dalmatia. _P. frigidus_ occurs not
only in the high Alps, but also in Lapland. _P. Schmidti_ and _P.
salamandra_ are found in Carinthia, Servia, and Transylvania; and one
species also inhabits the Pyrenees and another the Italian Mountains.
Finally, the only English species of _Pezotettix_, viz. _P. pedestris_,
has been taken in Sweden, Denmark, and then again in Austria, Hungary,
Servia, etc., as far east as the Volga, and also on the high Alps, in
Sardinia and the Abruzzi Mountains in Italy.

Very little, as I remarked, is known of the Asiatic range of this genus,
but either the same or a closely allied one has many representatives in
North and South America. Whether _Pezotettix_ is therefore of Asiatic
origin we cannot positively affirm, but whatever view we take, the
general range of the European species indicates that the migration took
place from the Alps in a south-easterly dire