6. TRICHIA ANDERSONI, Rex. Sporangia globose or obovoid, sessile, gregarious, closely crowded, or sometimes scattered, the wall thickened with minute scales, in color brownish-ochre or olivaceous. Mass of capillitium and spores yellow; elaters long, simple, 3-4 mic. in thickness, ending in a very long flexuous point, 14-18 mic. in length; spirals three or four, winding evenly and closely, perfectly smooth. Spores globose, minutely warted, 10-12 mic. in diameter. Growing on the inside of bark of Acer. Sporangium .4-.5 mm. in diameter. The capillitium is deep orange and the spores olivaceous, but this difference in shade of color between spores and capillitium occurs in other species. _Trichia advenula_, Mass., is a closely related species, the swellings in the elaters having no specific value. 7. TRICHIA INCONSPICUA, Rost. Sporangia very small, subglobose, sessile, collected together in clusters, or scattered, without any hypothallus; the wall brown, smooth and shining. Mass of capillitium and spores yellow; elaters long, simple, cylindric, 3-4 mic. in thickness, ending in smooth tapering points, 6-7 mic. in length; spirals three or four, close, not prominent, perfectly smooth. Spores globose, minutely warted, 10-12 mic. in diameter. Growing on bark of Platanus, etc. New York, _Peck_; Iowa, _McBride_. The sporangia spherical or reniform and very small. _b. Elaters spinulose._ 8. TRICHIA IOWENSIS, McBride. Sporangia subglobose, sessile, gregarious, scattered, or sometimes close and confluent; the wall thickened with minute scales, reddish-brown in color. Mass of capillitium and spores yellow; elaters quite variable, usually very long, but sometimes very short, simple, rarely branched, the thickness unequal, 3-4 mic. in the same elater, with occasional thicker swellings, bearing numerous scattered spines, usually about as long as the thickness of the elater, but sometimes much longer, those at the ends being similar; spirals three or four, fine and close, in places nearly obsolete. Spores globose, or more or less irregular, minutely warted, 9-11 mic. in diameter. Growing on old bark of Populus; Iowa, McBride. Sporangia .4-.5 mm. in diameter. This is a very curious species of Trichia; it suggests _Ophiotheca Wrightii_, but the elaters are short and simple, and there is no question as to the spirals upon them. I could find no branched elaters in my specimen. 9. TRICHIA SCABRA, Rost. Sporangia globose or somewhat irregular, sessile and closely crowded on a well-developed hypothallus; the wall thin, gold-yellow or orange to yellow-brown in color, smooth and shining. Mass of capillitium and spores orange or golden-yellow; elaters long, simple, 4-5 mic. in thickness, ending in a smooth tapering point, 5-8 mic. in length; spirals three or four, covered with numerous short acute spinules. Spores globose, minutely warted, 9-11 mic. in diameter. See Plate I, Fig. 23.