enings, the resultant network
of broad plates and bands widening at the points of intersection.

The genus _Enteridium_ is distinguished from _Reticularia_ chiefly by
the more perfectly developed sporangial walls. These are everywhere
membranous and do not show the abundant filiform dissipation so
characteristic of _Reticularia_. The resultant structure in
_Reticularia_ is a mass of more or less lengthened and anastomosing
threads; in _Enteridium_, an exceedingly delicate but sufficiently
persistent sponge. The "net-like, three-winged skeleton" referred to by
Rostafinski results from the union at one point of three adjoining
sporangia. Compare the section of the adjoining cells of a honeycomb.

Of this genus there are but two or three species, all so far occurring
in our territory.

=Key to the Species of Enteridium=

_A._ Fructification umber brown 1. _E. splendens_

_B._ Fructification olivaceous 2. _E. olivaceum_

_C._ Fructification minute, 1-2 mm. 3. _E. minutum_

1. ENTERIDIUM SPLENDENS _Morg._

PLATE I., Figs. 1, 1 _a_, 1 _b_; PLATE XII., Figs. 4, 5.

1876. _Reticularia_ (?) _rozeanum_ Rost., _Mon. App._, p. 33.
1889. _Enteridium rozeanum_ (Rost.) Wing., _Proc. Phil. Acad._,
p. 156.
1892. _Enteridium rozeanum_ Wingate, Macbr., _Bull. Lab. Nat. Hist.
Iowa_, II., p. 117.
1893. _Reticularia splendens_ Morg., _Jour. Cin. Soc._, p. 11.
1899. _Enteridium splendens_ Morg., Morg. _in litt._

Aethalium pulvinate, even, or somewhat irregular, unevenly swollen or
inflated, lobate or compound, covered by an exceedingly thin, generally
smooth, shining, but never white, pellicle or cortex, brown, from 1-6
cm. in diameter; hypothallus white, often wide extending; capillitium
none; the sporangial walls thin and brown forming a network as above
described; spore-mass umber, spores by transmitted light pale, about
two-thirds of the surface reticulate, the rest nearly smooth, 7-9 mu.

Very common, especially west, on decaying logs and stumps of every
description. Easily distinguished by its brown color and smooth,
shining, though uneven surface. The plasmodium as it emerges to form
fruit is pale pink or flesh color, slowly deepening to brown as maturity
advances. The first emergence is a watery white.

New England, Canada, to Minnesota and Nebraska, South Dakota.

In 1876 Rostafinski provisionally referred to the gen