p. 90.

Sporangia discoidal or saucer-shaped, gregarious, stipitate, erect or
nodding, grayish-white, the peridium thin, breaking irregularly and
persistent; stipe subulate, striate, reddish brown, transparent;
capillitium variable as above stated; spores pale violet-brown,
spinulose or nearly smooth, about 9 mu.

In _Mycetozoa, 2nd ed._, the spores are described as "dark or pale
purplish brown, spinose, spinulose or nearly smooth, 9-17 mu in
diameter." This would seem too great a variation even in this protean
species. The only specimens in our herbarium are from the Congo valley.
The spores are pale and nearly smooth, as in _Tilmadoche alba_, and 9 mu.
Spores 17 mu suggest immaturity; penultimate cell-division.

The synonymy above cited shows how this species has impressed careful
students. Doubtless in every case the reference is correct, judging from
the specimen each author had before him, although it is hard to see how
_Chondrioderma_ might have been suggested.

The species is evidently tropical, though reported from Europe.

=4. Craterium= _Trentepohl_

1797. _Craterium_ Trentepohl, Roth, _Catal._, I., p. 224.

Sporangia more or less distinctly cyathiform, stipitate, the peridium
generally plainly of two layers or even of three, opening at the top by
circumscission more or less definite, or by a distinct lid, the upper
part calcareous often to a marked degree, the lower, cartilaginous, long
persistent as a vasiform cup containing the capillitium and spores, the
calcareous nodes aggregating more or less to form a pseudo-columella.

This genus is distinguished from _Physarum_ and _Badhamia_ chiefly by
the form of the sporangia and the method of dehiscence. The capillitium
is in some specimens particularly, of the _Physarum_ type; in others,
like that of _Badhamia_. There are accordingly species that receive at
the hands of different authors diverse generic reference as one feature
or another in the structure is emphasized in the different cases. It is
granted that it is hard to draw the line sometimes between forms in
which the dehiscence is irregularly circumscissile and those in which
the wall breaks without any regularity whatever, since, in all, the
breaking up of the peridium usually begins at the top. Species here
included will, however, offer little ambiguity.

=Key to the Species of Craterium=

A. Dehiscence circumscissile or by the breaking up of the upper wall
of th