§1. TYPHOIDES. Threads of the capillitium repeatedly branching and anastomosing, to form a dense network of small meshes, with innumerable short, free extremities. 1. COMATRICHA TYPHINA, Roth. Sporangia short, erect or a little curved, cylindric or usually narrowing slightly upward, the base quite blunt, the apex more rounded, growing together on a thin hypothallus. Stipe and columella brown or blackish, tapering upward and vanishing near the apex of the sporangium, the stipe much shorter than the columella. Capillitium of slender flexuous tawny-brown threads; these branch repeatedly, forming an intricate network of small irregular meshes, ending in very short free extremities. Spores globose, violaceous, very minutely warted, 6-8 mic. in diameter. Growing on old wood, mosses, etc. Sporangium with the stipe 2-4 mm. in height, the stipe much the shorter, the sporangium .35-.40 mm. in thickness. _Stemonitis typhoides_, Fries, S. M. 2. COMATRICHA ÆQUALIS, Pk. Sporangia usually more or less inclined or curved and nodding, cylindric, obtuse at each end, growing together on a thin hypothallus. Stipe and columella slender, smooth, black, extending nearly or quite to the apex of the sporangium, the stipe longer than the columella. Capillitium of very slender flexuous tawny-brown threads; these branch repeatedly, forming an intricate network of small irregular meshes, ending in very short free extremities. Spores globose, minutely warted, dark violaceous, 7-9 mic. in diameter. Growing on old wood. Sporangium 1.5-3 mm. in height by .35-.40 mm. in thickness, the stipe usually about the same length as the sporangium, but sometimes nearly twice as long. The capillitium is rather looser than in _C. typhina_, whence the drooping habit. Peck, Thirty-first Report, p. 42. 3. COMATRICHA NIGRA, Pers. Sporangia globose or ovoid to ellipsoid or oblong, erect or sometimes inclined or even nodding. The stipe very long, smooth and black, tapering upward, expanding at the base into a small circular hypothallus; the columella short, reaching from one-half to three-fourths the height of the sporangium. Capillitium of slender flexuous brown threads, which branch repeatedly, forming a dense intricate network of small meshes, ending in very short free extremities. Spores globose, even, dark violaceous, 8-10 mic. in diameter. Growing on old wood, leaves, etc. Sporangium .5-1.5 mm. in height, .5-.8 mm. in diameter, the stipe 1.5-3 mm. long or sometimes considerably longer. This species seems to be rare in this country. I have preferred the name adopted by Schroeter to Rostafinski's _Comatricha Friesiana_.