on Hoehnel, _Akad. Wiss. Wien; Math-nat. KL._,
CXVIII., p. 431.

Sporangium wall rough with blunt spine-like processes, otherwise as
_Diderma_.

One species, _op. cit._, p. 432, _P. echinocephala_ v. Hoehn.

Java. Might as well be called _Diderma echinocephalum_, one would think.
Structure is that of _Leangium_. The striking character is a surface
modification of the outer peridium, according to the description.

ORDER II

=STEMONITALES=

Capillitium present, thread-like, arising in typical cases from a
well-developed columella; spores in mass, black or violet-brown, more
rarely ferruginous.

=Key to the Families of Stemonitales=

_A._ Fructification aethalioid, capillitium poorly
defined; columella rudimentary or none AMAUROCHAETACEAE

_B._ Fructification of distinct sporangia, capillitium
well defined; the columella generally prominent,
long and abundantly branched throughout STEMONITACEAE

_C._ Sporangia distinct; capillitium developed chiefly
or only, from the summit of the columella LAMPRODERMACEAE

_A._ AMAUROCHAETACEAE

Fructification aethalioid, an inch or two in diameter, in form varying
with the habitat and place; capillitium dendroid, consisting of rather
stout branches which rise irregularly more or less vertically from the
hypothallus, branch repeatedly, often anastomose to form a network,
especially toward the periphery; spores black.

A single genus--

=1. Amaurochaete= _Rostafinski_

1873. _Amaurochaete_ Rost., _Versuch._, p. 8.

The genus _Amaurochaete_ as defined by Rostafinski and the genus
_Reticularia_ as represented by _R. lycoperdon_ Bull. stand, the
expression, perhaps, of not dissimilar histories. Whether in regressive
or progressive series, each to-day presents a case of arrested
development. Each in aethalioid fructification, reveals a mass of
involved individual (?) sporangia, so imperfectly developed that their
outlines can be inferred rather than anywhere, with absolute
definiteness, certainly ascertained. Perhaps, because similar sporangia
in the group to which either belongs, do come under other circumstances,
to more perfect individual form and function--perhaps for this reason we
may look upon these aethalia as exhibiting a suspended performance; the
sporangia have failed to go forward to what was evidently a possible,
though apparently not an essential destiny in form and figure.