he lime is more uniformly distributed through the
capillitium, and accordingly the nucleus is not conspicuous, its place
being taken by two or three nodes plainly larger than the others. The
peculiar brown metallic lustre of the peridial wall, and the strongly
developed calcareous patches with which the peridium is covered are
constant features.

That this is the _Didymium columbinum_ Berk., or _T. columbina_ (Berk.)
Rost., is very doubtful; the specific name given by Wingate becomes
inapplicable when the series is transferred to _Physarum_, since in that
genus the combination is already a synonym. See _P. compactum_
Ehrenberg, _Syl. Myc. Berl._, p. 21 (1818), cited repeatedly in the
synonymy; Fries, _op. cit._, Vol. III., p. 101. So also _P. columbinum,
l. c._, pp. 133, 135, etc., to say nothing of the fate of Persoon's
first record, _Obs. Mycol. pars prim._, p. 5, 1796. This is Wingate's
species, let it bear his name.

30. PHYSARUM NEWTONI _Macbr._

PLATE XIV., Figs. 5, 5 _a_, 5 _b_.

1893. _Physarum newtoni_ Macbr., _Bull. Lab. Nat. Hist. Iowa_, II.,
p. 390.
1899. _Physarum newtoni_ Macbr., _N. A. S._, p. 37.
1911. _Physarum newtoni_ Macbr., Lister, _Mycetozoa, 2nd ed._, p. 54.

Sporangia simple, gregarious, short-stipitate or sessile, globulose or
flattened, when not globose, depressed and deeply umbilicate above,
purple, smooth, thin-walled, stipe when present very short and
concolorous; columella none; hypothallus none; capillitium abundant,
delicate, with more or less well-developed nodules, which are also
concolorous; spores by transmitted light, dark brown, thick-walled,
rough, nucleated, about 10 mu.

A very handsome little species collected by Professor G. W. Newton in
Colorado, at an altitude of several thousand feet. Easily recognized by
its almost sessile, rose purple, generally umbilicate sporangium.

31. PHYSARUM PSITTACINUM _Ditm._

1817. _Physarum psittacinum_ Ditm., Sturm, _Deutsch. Fl. Pilze_,
p. 125.
1829. _Physarum psittacinum_ Ditm., Fries, _Syst. Myc._, III., p. 134.
1873. _Physarum psittacinum_ Ditm., Rost., _Mon._, p. 104.
1911. _Physarum psittacinum_ Ditm., Lister, _Mycetozoa, 2nd ed._,
p. 55.

Sporangia scattered or gregarious, globose or depressed-globose, or
reniform, iridescent-blue, mottled with various tints, red, orange,
yellow, white, stipitate; stipe equal, or tapering slightly upward,
rugose, orange or orange red, witho