the more delicate spores.
On rotten wood.

13. DIDERMA OCHRACEUM _Hoffm._

1795. _Diderma ochraceum_ Hoffm., _Deutsch. Fl. Tab._ 9, 2, b.
1911. _Diderma ochraceum_ Hoffm., List., _Mycetozoa, 2nd ed._, p. 109.

Sporangia gregarious or clustered, .7-1 mm., sessile, globose or
sometimes plasmodiocarpous, ochraceous yellow; outer wall cartilaginous
with yellow deposits of lime, the inner also yellow, adherent or free;
columella not distinct; capillitium simple or branching, purple-brown,
hyaline at base; spores spinulose, purplish-grey, 9-11 mu.

Mr. Lister reports this species from Massachusetts.

14. DIDERMA ROANENSE (_Rex_) _Macbr._

1893. _Chondrioderma roanense_ Rex, _Proc. Phil. Acad._, p. 368.

Sporangia scattered, discoidal, thin, flattened or slightly convex
above, plane or plano-concave below, umber-brown, stipitate, the outer
peridium smooth, brittle, rupturing irregularly, the basal fragments
somewhat persistent, concrete with the inner peridium, which is pure
white, except near the columella, and punctate; stipe short, variable,
longitudinally ridged, jet-black; hypothallus none; columella flat,
discoidal, pale ochraceous; capillitium sparse, white or colorless,
composed of simple, rarely forked, sinuous threads occasionally joined
by lateral branches; spores dark violaceous, distinctly warted, 12-14 mu.

This species is readily distinguished by its color. The sporangia, found
on rotten wood, are large, 1 mm., brown, and have thick, persistent
walls. Dr. Rex considered that the species differs from other related
forms not only in color, but in the well-marked discoidal columella and
the jet-black irregular stipe. It is perhaps most nearly related to the
following species.

Tennessee.

15. DIDERMA RADIATUM (_Linn._) _Morg._

PLATE XVIII., Fig. 8

1753. _Lycoperdon radiatum_ Linn. (?) _Sp. Pl._, 1654.
1797. _Didymium stellare_ Schrad., _Nov. Gen. Pl._, p. 21.
1801. _Diderma stellare_ (Schrad.) Persoon, _Syn._, p. 164.
1875. _Chondrioderma radiatum_ (Linn.) Rost., _Mon._, p. 182.
1894. _Diderma radiatum_ (Linn.) Morg., _Jour. Cin. Soc._, p. 66.
1899. _Diderma stellare_ Schrad., Macbr., _N. A. S._, p 104.
1911. _Diderma radiatum_ List., _Mycetozoa, 2nd ed._, p. 112.

Sporangia scattered, depressed-globose, sometimes also flattened below,
stipitate, smooth or slightly corrugate, ashen or brownish, about 1 mm.
in diameter, the peridium dehiscing irregularly or somewhat rad