elanosporeae_.

The recorded edible species of the spore section Dermini are found in
Pholiota, Cortinarius, and Paxillus. The larger proportion of the
Pholiotas grow upon tree stumps. They have a fugacious, persistent
friable ring, and are liable to be confused with the Cortinarii, unless
attention is paid to the spidery veil and the iron-rust tint of the
spores of the latter. Only a few of the species are recorded as edible,
but none are known to be poisonous. Cortinarius is a large genus. It
contains a larger proportion of edible species than Pholiota, and none
are recorded as poisonous. The cobweb-like veil which extends from stem
to margin of cap in the young species, and the rust-colored spores which
dust the gills as the species mature, distinguish the genus from all
others.

A characteristic feature of Paxillus, and one which makes it easily
distinguishable from others of the same group, is the ease with which
the gills as a whole can be separated from the substance or fleshy
portion of the cap. There is an exception to this in the species
Paxillus involutus, recorded by Peck as edible.

POLYPOREI.

Hymenium lining the cavity of tubes or pores which are sometimes broken
up into teeth or concentric plates.--Berkeley's Outlines.

The plants of this second primary group or order of the family
Hymenomycetes exhibit a greater dissimilarity of form and texture than
do those of the Agaricini. Some of its genera consist almost wholly of
coriaceous or woody plants. A few contain fleshy ones. Some of the
species have a distinct stem, while others are stemless. With regard to
the receptacle in the plants of the genera _Boletus_, _Strobilomyces_,
etc., it forms a perfect cap, like that of the common Agaric, a cushion
of tubes taking the place of gills on the under surface of the cap, the
hymenium in this case lining the inner surface of the tubes from which
the spores drop when mature.

In some species, such as those of the genus Poria, the receptacle is
reduced to a single thin fibrous stratum, adhering closely to the matrix
and exposing a surface of crowded pores, and in others it consists of
fibrous strata formed in concentric layers.

A number of groups, each of which was treated in the original Friesian
classification as a single genus, have more recently been recognized as
comprising several distinct genera. In the Saccardian system the genera
Trametes, Daedalea, Merulius, Porothelium, and Fistulina st