_Mycetozoa_, p. 129.
1899. _Lamproderma sauteri_ Rost., Macbr., _N. A. S._, p. 140.

Sporangia gregarious, globose, dull black, the peridium when present
silvery, shining, or simply smooth, transparent and without
iridescence, stipitate; stipe short, black, tapering rapidly upward,
annulate with the persisting base of the peridium; columella short,
thick, truncate, and widened at the top; hypothallus well developed,
brown or purple; capillitium dense, made up of dark brown branches,
numerous and rather slender, repeatedly branched and anastomosing toward
the surface to form a slight delicate network with abundant free ends;
spores dark purple brown, rough, 14-16 mu.

This species in outward appearance resembles _L. physaroides_, from
which it is easily distinguished by the much greater diameter of the
globose sporangium, 1 mm. or more. The persistent base of the peridium
is also characteristic, very prominent sometimes, and visible to the
naked eye. The capillitium is also unlike that of _L. physaroides_;
resembles more nearly that of _L. violaceum_. From the latter species
_L. robustum_ is distinguished by the color of the peridium, and by the
larger, darker spores and generally different capillitium. In our former
edition this is called _L. sauteri_ Rost. That much-quoted author
distinguished _L. violaceum_ and _L. sauteri_; the English authors make
the last named a variety only of the former. This our American species
is _not_.

It is, as presented in our western mountains, clear-cut, well defined,
not a variety of anything. The original name is therefore restored.

_Lamproderma arcyrioides_ (Somm.) Morgan is probably a form of _L.
columbinum_. The original _L. arcyrioides_ has not yet been certainly
identified in North America; see following species.

Colorado, Oregon, Washington, California.

3. LAMPRODERMA COLUMBINUM (_Pers._) _Rost._

1796. _Physarum columbinum_ Pers., _Obs. Myc._, I., p. 5.
1875. _Lamproderma columbinum_ Rost., _Mon._, p. 203.

Sporangia scattered, gregarious; rich violet or purple with metallic
iridescence, globose, stipitate; the stipe long, three-fourths the total
height, slender, subulate, black; hypothallus scant, purplish or brown;
columella small, one-third the height or less, tapering or acute, black;
the capillitium brown throughout, not dense, arising from nearly all
parts of the columella, freely branching and anastomosing to an open,
large-meshed network; spore-ma