anishing without order or symmetry, generally
giving rise at the sides, and especially above, to long slender flexuous
threads; outer cortex silvery white; hypothallus distinct, white;
spore-mass and threads umber or rusty brown.

A single species,--

1. RETICULARIA LYCOPERDON (_Bull._) _Rost._

PLATE X., Figs. 7, 7 _a_; PLATE XII., Fig. 3.

1791. _Reticularia lycoperdon_ Bull., _Champ. de la France_, p. 95.

Aethalium pulvinate, 2-8 cm. broad, at first silvery white, later less
lustrous, the cortex irregularly and slowly deciduous; hypothallus at
first conspicuous as a white margin extending round the entire
aethalium, evanescent without, but persisting as a firm membrane beneath
the spore-mass, pseudo-capillitium abundant, tending to form erect
central masses which persist long after the greater part of the fruit
has been scattered by the winds; spore-mass umber, spores by transmitted
light pale, reticulate over about two-thirds of the surface, the
remainder slightly warted, 8-9 mu.

Not common. Often confused with the following, the spores of the two
forms being very much alike; the internal structure, entirely different,
and once compared, the two are thereafter easily distinguished at sight
by external characters. The sporangial make-up is indifferent, confused.
It represents a phase in development whence might issue columellae with
capillitium-branches or distinct tubular sporangia with persisting
walls; or are such structures here but reminiscent only? Compare
_Amaurochaete atra_, where similar conditions prevail. There
differentiation goes on to the formation of a structure of which
_Stemonitis_ is type; here the sporangium-wall becomes dominant; suffers
modification for spore-disposal, an idea reaching fair expression in
_Cribraria_ and _Dictydium_.

The plasmodium is white, noted Bulliard. Fries cites with approval the
words of Schweinitz,--"color corticis ab initio argenteus sericeo
nitore insignis; sed deinde sordescit e griseo in subfuscum vergens."
Sometimes the surface does indeed shine as silver!

The fructification appears to be isolated in each case; the entire
plasmodium consumed in a single plasmodiocarp.

Widely distributed. Maine to California, and south.

=2. Enteridium= _Ehrenberg_

1818. _Enteridium_ Ehrenberg, Link and Spreng., _Jahrb., Bd._ II.,
p. 55.

Fructification aethalioid; the confluent sporangia inextricably
interwoven, the walls perforate by large op