This is the common form in the United States. Massee describes it as _C. cylindricum_ Mass., and it seems not to occur in Europe. Lister has put it in with _C. leucocephalum_, from which its more delicate structure and elegant cylindrical shape certainly distinguish it. The dehiscence is even more regular than in the preceding species and approaches that of _C. minutum_ Leers., with bleached forms of which it must not be confused. _N. A. F._, 1400. _C. minimum_ Berk. & C. has here priority. Massee regards this name as indicating a distinct species. We have been unable to determine what the authors really had before them, and adopt accordingly the first available combination. New England to Iowa and south; reported also from the orient. 5. CRATERIUM CONCINNUM _Rex._ 1893. _Craterium concinnum_ Rex, _Proc. Phila. Acad._, p. 370. Sporangia scattered, usually minute, broadly funnel-shaped, stipitate. The peridium simple, variously colored by innate lime granules, opening by a regular cap or operculum, brownish white, darkest in the centre, always more or less convex; stipe equalling the cup in height, dark brown, longitudinally ridged; the capillitium a close-meshed network, with small rounded or slightly angular masses of ochre-brown lime-granules, larger toward the centre; spores pale brown, minutely warted, 9-10 mu. This species differs from the following, to which it seems most nearly allied, in form, color, as in the capillitium, and color of the spores. In habitat, however, it seems no less distinct, being found always (?) on the spines of decaying chestnut-burs lying on the ground, and in company with that other peculiar species _Lachnobolus globosus_. The range is probably that of the chestnut, _Castanea dentata_ Borkhausen, east of the Mississippi River. 6. CRATERIUM MINUTUM (_Leers_) _Fr._ PLATE XV., Fig. 5. 1775. _Peziza minuta_ Leers, _Fl. Herborn_, p. 277. 1797. _Craterium pedunculatum_ Trent., Roth., _Catal. Bot._, I., p. 224. 1813. _Craterium vulgare_ Ditmar, Sturm, _Deutsch. Fl. Pilze_, p. 17. 1829. _Craterium pedunculatum_ Trent., Fr., _Syst. Myc._, III., p. 150. 1829. _Craterium minutum_ Leers, Fr., _Syst. Myc._, III., p. 151. 1893. _Craterium pedunculatum_ Trent., Macbr., _Bull. Lab. Nat. Hist. Iowa_, II, p. 385. 1894. _Craterium pedunculatum_ Trent., Lister, _Mycetozoa_, p. 70. 1899. _Craterium minutum_ (Leers) Fr., Macbr., _N. A. S._, p. 78. 1911. _Craterium minutum_ Fr., List., _Mycetozoa, 2nd ed._, p. 94.