This curious but elegant little species is represented by a single colony collected by Professor Morton Peck in Iowa. It resembles _D. sauteri_ but is distinguished by the plicate white wall, the stout columella with its lateral extensions, as by 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.