§1. EU-CRATERIUM. Sporangium at maturity dehiscent in a regular circumscissile manner, the apex falling away as a lid, leaving behind the more persistent cup-shaped portion. 1. CRATERIUM MINUTUM, Leers. Sporangium cyathiform, stipitate; the lid slightly convex, discrete from the first, usually depressed below the rim of the cup, falling away at maturity, and leaving a smooth, circular margin to the lower cyathiform portion. The wall a thick, firm, yellow-brown membrane, the outer surface of the cup entirely naked, smooth and shining, varying greatly in color from alutaceous or ochraceous to various shades of brown; the lid usually whitened by a thin layer of granules of lime. Stipe short, erect or bent, and slightly curved at the apex, varying in color from rusty yellow to reddish brown, longitudinally plicate, arising from a small, circular hypothallus. Capillitium of tubules forming a loose net-work, bearing large, irregular, white nodules of lime, which are sometimes confluent in the axis of the sporangium. Spores globose, very minutely warted, violaceous, 8-10 mic. in diameter. Growing on old wood, sticks, leaves, etc. Sporangium, together with the stipe, .8-1.4 mm. in height and .3-.5 mm. in diameter, the stipe usually shorter than the sporangium, sometimes equal to it in length, rarely longer. The latest authorities include the three species _Craterium vulgare_, _C. pyriforme_, and _C. minutum_ of Rostafinski's monograph all in one species. 2. CRATERIUM CONCINNUM, Rex. Sporangium usually minute, broadly funnel-shaped, stipitate; operculum always more or less convex, rarely approaching a hemispherical shape, dehiscent in a regular circumscissile manner. The wall a thick, brownish membrane, externally smooth and variously colored, sometimes uniformly light or dark umber, sometimes dark brown below and brownish white above; the operculum brownish white, darkest in the center. Stipe short, dark brown, longitudinally ridged. Capillitium of tubules forming a close-meshed net-work, bearing small rounded or slightly angular nodules of lime, ochre-brown in color. Spores globose, very minutely warted, brown, 9-10 mic. in diameter. Growing usually upon chestnut-burs, and frequently associated with _Lachnobulus globosus_. Sporangium .5-.8 mm. in height including the stipe and .2-.5 mm. in diameter at the top, the stipe equaling the sporangium in length. It is readily distinguished by its small nodules in the capillitium, which are invariably of a dull, brownish-ochre color.