ily, Southern Italy, and the
Caucasus. It is evidently a very ancient genus. The species live in moss
or underground, and are not likely to be transported across the sea by
accidental or occasional means of distribution.

Still another genus, which resembles _Acme_ in its geographical
distribution, is _Daudebardia_--a small slug-like mollusc with a tiny
shell. It does not, however, range nearly so far north or west as
_Acme_, for it occurs neither in the British Islands nor in Spain or the
Pyrenees.

I shall not be able to refer to more than a few of the most typical
Alpine species of Lepidoptera, but they may be taken as fair examples of
the geographical distribution of the rest of the group.

Even those visitors to Switzerland who do not claim to be naturalists
have heard of the remarkably handsome and stately Butterfly known as
Apollo. To the ardent entomologist, the first sight of this typical
Alpine species is a never-to-be-forgotten delight, and he generally
brings home with him a rich harvest of specimens. The more experienced
Butterfly hunter knows that there are no less than three different kinds
of Apollo--or, as we should say more correctly, of Parnassius--in
Switzerland. There is first the common Apollo (_Parnassius Apollo_),
then the rarer and more local _P. delius_, which inhabits more elevated
regions, and finally the still scarcer _P. mnemosyne_, which is only
known from the highest mountain ranges. It may be a surprise to those
who have accustomed themselves to connect Apollo with the Alps, and who
think the two belong together and cannot do without one another, to hear
that it is by no means confined to them. It is also found in
Scandinavia, France, Spain, Russia, and in Siberia. _Parnassius delius_
is confined to the European Alps and the mountains of Central Asia,
while _P. mnemosyne_ is known from the Pyrenees, Sweden, Hungary,
Sicily, Russia, and Western Asia. One other Parnassius inhabits Europe,
viz., _P. Nordmanni_ of the Caucasus, but all the remaining species of
the genus--and there are nearly thirty more--are confined to Central
Asia. A few, as we have seen, have reached Europe, some have travelled
to the Himalayan Mountains, and others to Western North America. The
centre of distribution is certainly in Central Asia, and we have no
reason to suppose that the original home in this case does not agree
with that centre.

_Melitaea_, a genus to which some of our British Fritillaries belong,