, _Mycetozoa_, p. 58.
1899. _Physarum conglomeratum_ (Fr.) Rost., Macbr., _N. A. S._, p. 31.
1911. _Physarum conglomeratum_ Rost., List., _Mycetozoa, 2nd ed._,
p. 80.

Sporangia depressed, globose, or irregular, sessile, more or less
aggregated, ochraceous-yellow, peridium double, the outer, thick,
cartilaginous, at length irregularly ruptured, and reflexed, disclosing
the more delicate, ashen-gray, inner membrane which encloses capillitium
and spores; capillitium abundant, showing large, white irregular
calcareous thickenings which are often consolidated in some sporangia
tend to aggregate at the centre; spore-mass brown, spores violaceous,
slightly roughened, 8-10 mu.

This beautiful species shows a peridium as distinctly double as in any
diderma. The outer peridium is reflexed exactly as in some species of
that genus; is yellow without, white within, and withal long persistent.
The capillitium of course distinguishes the species instantly as a
physarum. By the size of the spores it is distinguished from the species
preceding. This being a decisive specific character the synonymy prior
to Rostafinski is somewhat uncertain. The specific name adopted by the
Polish author is therefore approved, although perhaps not the earliest.

Rare. The only specimens thus far are from Tennessee and Louisiana.

11. PHYSARUM MORTONI _Macbr. n. s._

PLATE XX., Figs. 2, 2 _a_.

Sporangia gregarious, clustered but distinct, sessile small, about .75
mm., bright yellow, peridium double. The outer rough, breaking up into
comparatively few rather large deciduous scales, the inner peridium
white, calcareous, both persisting below to form a distinct cup;
capillitium lax, the nodes white, large, angular; columella none;
hypothallus none; spores distinctly rough, dark brown with the usual
purple shadow, 10-12 mu.

A very distinct little species related, no doubt, to _P. contextum_,
but different in habit. It is never crowded, shows no plasmodiocarpous
tendencies, while the outer peridium is generally deciduous except at
the base and falls in flakes.

Collected several times in the Three Sisters Mountains of Oregon by
_Professor Morton E. Peck._

12. PHYSARUM BRUNNEOLUM (_Phillips_) _Mass._

PLATE XX., Figs. 7, 7 _a_.

1877. _Diderma brunneolum_ Phillips, _Grev._, V., p. 114.
1888. _Diderma brunneolum_ Phill., Saccardo, _Syll. Fung._, No. 1292.
1892. _Physarum brunneolum_ Phill., Massee, _Mon._, p. 280,