Sporangia scattered, orange or nut-brown, very minute, .1-.3 mm. or less, globose or ellipsoidal, stipitate, erect or nodding; hypothallus none; stipe short, 1-3 times the sporangium, filiform, tapering upward, brown; the calyculus variable, sometimes well marked and separated from the net when fully mature, by a shallow constriction, more commonly small or entirely wanting, especially in the spherical sporangia; net simple, large meshed, without nodal expansions, the threads flattened; spore-mass yellow, spores by transmitted light, pale, nearly smooth, 5-6 mu. A most beautiful tiny species. Generally in all the specimens before us, a perfect, spherical net, firm enough to retain its place and structure after all the spores have been scattered. When mature the spore-mass seems to roll about as a ball, freely within the net, the spores being thus gradually dispersed. The calyculus when present is without veins. _C. minima_ Berk. & C., and _C. microscopica_ Berk. & C. are doubtless the same thing. _Grev._, II., p. 67, 1823. See also _Bot. Gaz._, XIX., 397. Rare. Pennsylvania, South Carolina, Missouri, Iowa; Black Hills, South Dakota. 4. CRIBRARIA RUFA (_Roth_) _Rost._ PLATE XIX., Fig. 8. 1788. _Stemonitis rufa_ Roth, _Fl. Germ._, I., p. 548. 1794. _Cribraria rufescens_ Pers., Roemer, _N. Mag. Bot._, I., p. 91. 1797. _Cribraria fulva_ Schrad., _Nov. Gen. Pl._, p. 5. Sporangia scattered, sub-globose or turbinate, dark or reddish orange, .5-.7 mm. in diameter, erect, stipitate; stipe about equalling the height of the sporangium or longer, dark brown or black; calyculus one-third to one-half the sporangium, the margin toothed, the wall ribbed and continuous with the open wide-meshed net; the network deep yellow or orange, the threads flattened; the nodes not thickened, little differentiated; spores concolorous, by transmitted light, pale yellow, verruculose, 5-7 mu. Similar to the preceding, but generally much larger and not so much inclined to brown. The size, however, is extremely variable in sporangia from the same plasmodium (reported white), some no larger than those of the species reckoned most minute. Oregon. _Professor Morton Peck._ 5. CRIBRARIA SPLENDENS (_Schrader_) _Rost._ PLATE XIX., Fig. 10. 1797. _Dictydium splendens_ Schrad., _Nov. Gen._, p. 14. 1801. _Cribraria splendens_ (Schrad.) Pers., _Syn. Fung._, p. 191. Sporangia gregarious, globose, dusky yellow when filled with spores, dull or dusky brown when these are discharged, stipitate; stipe long, 3-4 times the sporangium, subulate, erect-nodding, brown; hypothallus none; network brown, with large meshes, imperfectly defined nodes and flattened threads; calyculus none, its place supplied by nine or ten distinct, firm ribs which radiate from the stipe and support the net, branching to blend with its reticulations; spore-mass yellow, spores by transmitted light, colorless, smooth or nearly so, 6-7.5 mu.