Growing on rotten wood, especially of oak. Sporangium .5-.6 mm. in diameter, the stipe from three to five times as long. This species appears to be intermediate between _Cribraria vulgaris_ and _Cribraria intricata_; the nodules are usually large and irregular, but the characteristic parallel threads of _C. intricata_ do not often occur. The outer membrane of the calyculus is by no means always absent. 4. CRIBRARIA ELEGANS, B. & C. Sporangium rather large, globose, stipitate, somewhat cernuous; the calyculus thickly coated inside with dark purple granules, faintly ribbed, occupying about a third part of the sporangium; the network of slender threads, with large irregular dark purple nodules, quite variable in shape and size, angular and lobed, below sometimes much elongated, the meshes very irregular. Stipe rather short, tapering upward, bent at the apex, dark purple in color. Spores in the mass bright purple, globose, even, 5-7 mic. in diameter. Growing on old wood. Sporangium .4-.5 mm. in diameter, the stipe two or three times as long. It does not appear to be greatly different from _Cribraria purpurea_, Schrad. _b. Sporangium, small._ 5. CRIBRARIA TENELLA, Schrad. Sporangium small, globose, stipitate, cernuous; the calyculus brown, shining, granulose within and faintly ribbed, occupying from one-fourth to one-half the sporangium, sometimes the outer thin membrane early disappearing; the network of slender threads with small roundish or irregular nodules at the angles, each with several (4-8) radiating threads, sometimes two or three with free extremities, the meshes triangular or rhombic. Stipe long, tapering upward, flexuous, curved at the apex, purplish-brown in color. Spores pale ochraceous in mass, globose, even, 5-7 mic. in diameter. Growing on old wood. The sporangium .3-.4 mm. in diameter, the stipe three to five times as long. This is a much more delicate species than _Cribraria dictydioides_. The calyculus is variable in size; in some examples the thin connecting membrane between the ribs has disappeared. 6. CRIBRARIA MICROCARPA, Schrad. Sporangium very small, globose, stipitate, somewhat cernuous; the calyculus represented by a few short brown ribs, the outer membrane soon disappearing; the network of slender threads, with small roundish nodules at the angles, each with several (4-6) radiating threads, with an occasional free extremity, the meshes largely rhombic. Stipe very long, slender, somewhat flexuous, bent at the apex, purplish-brown in color. Spores in mass pale ochraceous, globose, even, 6-7 mic. in diameter. Growing on old wood. Sporangium .22-.27 mm. in diameter, the stipes 1-2 mm. in length. Readily distinguished by its very small sporangium and the comparatively very long stem. I am indebted to Dr. George A. Rex for specimens of this species.