Sporangia clustered, usually in small tufts 1 cm. wide, rusty brown in color, 8–10 mm., including the stipe, which is jet black, shining, and much expanded at the base; hypothallus continuous, well-developed, a thin, transparent pellicle; columella black, tapering upward, giving off at intervals the capillitial branches, and becoming dissipated just below the obtuse apex; inner capillitial network very open, the branches far apart, anastomosing but a few times before breaking into the surface net to form large, irregular meshes, 50–125 µ; spores minutely roughened, fuscous, 8–9 µ.

These three forms, 8, 9, 10, are sometimes entered as varieties of a single species. Dr. Rex himself was inclined to take that view. There is no doubt of close similarity; it is a question of clearness in our dealing with the subject.

All three forms occur abundantly in the Mississippi Valley, but are generally,—always, as it seems to the writer,—distinguishable by the hand-lens. If we take No. 9 as type, 10 has an eccentric columella; 8 is shorter, about 1 cm., of a different tint, Dr. Rex even says "spores ferruginous in mass". To the west and southwest, the capillitium becomes coarser, more decidedly brown. In short, however similar in presentation the phases may sometimes appear, it would seem that each at its best is distinct enough for immediate recognition.

West of the Mississippi River chiefly: Iowa, South Dakota, Nebraska, Kansas, Oklahoma, New Mexico, etc.

9. Stemonitis splendens Rost.

[Plate VI.], Figs. 6, 6 a, 6 c, 7, 7 a.

Sporangia clustered irregularly, sometimes forming patches 6–10 centimetres or more in extent, rich purple-brown in mass, cylindric, long, 15–18 mm., stipitate; stipe black, polished, shining, rising from a common hypothallus, which extends as a thin silvery film beneath the entire colony, but does not usually transcend its limits; columella black, percurrent, sparingly branched; capillitium of fuscous threads, within forming a network very open, the branches scarcely anastomosing until they reach the surface where they form the usual net of small meshes, pretty uniform in size, and presenting very few small, inconspicuous peridial processes; spores brown, very minutely warted, about 8 µ.

This elegant species occurs not rarely on rotten wood, usually in protected situations, although sometimes on the exposed surfaces of its habitat. The sporangia attain with us unusual height, sometimes 2 cm.; plasmodia, 6–8 cm., in diameter. The clear brown tufts appear in the autumn, marvels of graceful elegance and beauty; at sight easily recognizable by the large size and rich color. In Iowa it is almost universally present on fallen stems of Acer saccharinum Linn., and it appears to be widely distributed, by far the most beautiful of all this beautiful series.