This species stands just on the border-line between the tubiferas and the genus now before us. While on the one hand it possesses many characters such as the habit, form of sporangium, which are distinctly tubuline, on the other it shows in the upper peridial wall definite reticulations which suggest _Cribraria_. In freshly formed sporangia the reticulations are barely visible in the crown; later on they are more manifest, until, as spore-dispersal proceeds; the cribraria characters come out with sufficient distinctness, and in empty sporangia the reticulations may be seen to affect the entire peridial wall. The nodes are not expanded. The spores are pale by transmitted light, spinulose, about 6 mu. Plasmodium lead-colored. Found sometimes in large patches on rotten logs of various species. Not uncommon. Cf. _Lindbladia effusa_. New England, New York, Pennsylvania, South Carolina, Ohio, Illinois, Iowa, Washington; Canada. 2. CRIBRARIA MACROCARPA _Schrader._ PLATE XVII., Fig. 2. 1797. _Cribraria macrocarpa_ Schrad., _Nov. Gen. Plant._, p. 8. Sporangia more or less closely gregarious, yellowish brown, pear-shaped or obovate, large, .8-1 mm. in diameter, stipitate; stipe brown furrowed, erect or often nodding, about equal to the sporangium or longer; calyculus distinct, marked by numerous dark brown radiating ribs, iridescent, perforate above, deeply dentate, and merging gradually into the elegant network, of which the dark nodes are more distinctly expanded about half way up, less so at the apex and below, the filaments exceedingly delicate, simple, with occasional free ends projecting into the small meshes; spore-mass yellowish, spores by transmitted light almost colorless, minutely roughened, 5-6 mu. Perhaps the most striking characteristic of the present species, aside from its large size, is the peculiarly perforated cup or calyculus. Schrader's artist failed him here completely. The structure is exceedingly delicate, the peridium between the ribs and reticulations reduced to the last degree of tenuity, with the iridescence of the soap-bubble, here and there lapsed entirely. Withal the structure seems firm enough and persists until all the spores are dissipated by the wind. Easily distinguished from the preceding, its only rival in size, by the obovate or turbinate, netted sporangium, its much longer stem, and flat, perfectly formed nodes. Rare. New York, North Carolina, South Carolina, Oregon; Toronto, Canada. 3. CRIBRARIA MINUTISSIMA _Schweinitz._ PLATE XVII., Figs. 6, 6 _a_. 1832. _Cribraria minutissima_ Schw., _N. A. F._, No. 2362.