raphic
centre in the temperate zone, and especially in the colder portion of
that zone. It is a curious circumstance that all the extra-European
species of this genus _Agaricus_ may be referred to various European
subgenera.

In tropical countries it appears that the _Agarici_ occupy only a
secondary position in relation to other genera of fungi, such as
_Polyporus_, _Lenzites_, etc. North America, on the other hand, is
richer in species of _Agaricus_ than Europe; for whilst the majority
of typical forms are common to both continents, America further
possesses many species peculiar to itself. In the temperate zone, so
close is the analogy prevailing between the various countries in
respect to the _Agaricini_, that from Sweden to Italy, and as well in
England as North America, the same species are to be found. Of 500
_Agaricini_ met with in St. Petersburg, there are only two or three
which have not been discovered in Sweden; and again, of fifty species
known in Greenland, there is not one that is not common in Sweden. The
same remarks hold good in reference to the _Agaricini_ of Siberia,
Kamtschatka, the Ukraine, etc. The countries bordering upon the
Mediterranean possess, however, several peculiar types; and Eastern
and Western Europe present certain dissimilarities in their Agaric
inhabitants. Several species, for example, of _Armillaria_ and
_Tricholoma_, which have been found in Russia, have been met with in
Sweden only in Upland, that is, in the most eastern province; all the
species which belong to the so-called _abiegno-rupestres_ and
_pineto-montanae_ regions of Sweden are wanting in England; and it is
only in Scotland that the species of northern mountainous and
pine-bearing regions are met with--a circumstance explicable from the
similarity in physical features between Sweden and the northern
portions of Great Britain.

The species of _Coprinus_ appear to find suitable habitats in every
quarter of the globe.

The _Cortinariae_ predominate in the north; they abound in Northern
latitudes, especially on wooded hills; but the plains offer also some
peculiar species which flourish during the rainy days of August and
September. In less cold countries they are more scarce or entirely
absent. The species of the genus _Hygrophorus_ would at first seem to
have a similar geographical distribution to those of the last group;
but this is really not the case, for the same _Hygrophori_ are to be
found in nearly every cou