Sporangia in small heaped clusters.

i. Elaters roughened, no distinct rings
or spirals 1. _O. flavidum_

ii. Elaters with scattered rings; sometimes
faint spirals 3. _O. nitens_

B. Spores warted 4. _O. fulvum_

1. OLIGONEMA FLAVIDUM (_Peck_) _Mass._

1874. _Perichaena flavida_ Peck, _Rep. N. Y. Mus._, p. 76.
1892. _Oligonema flavidum_ (Peck) Mass., _Mon._, p. 171.

Sporangia crowded and superimposed, sessile in small masses or clusters
1 cm. or less, bright yellow, shining, the peridium thin but opaque,
yellow; capillitium of long, slender tubules usually simple, anon
branched, even, or with an occasional inflation, the sculpture confined
to warts or small, distinct spinules, roughening more or less
conspicuously the entire surface, the apices generally obtuse, anon
apiculate; spore-mass yellow, spores under the lens pale yellow,
irregularly globose, beautifully reticulate, the meshes large and few,
as in _Trichia favoginea_, 12-14 mu.

This species is marked by its capillitium, which is abundant for the
present genus. The threads are longer than in any other species, and not
infrequently branched, smooth, or more commonly, very distinctly
minutely spinulose throughout, no trace of rings or relief sculpture of
any sort, the spirals, that are to be expected, very imperfect, if
discernible at all. In habit the species resembles _O. nitens_, but the
colonies are much larger, and the sporangia higher and larger, attaining
1 mm.

New England to Iowa and Nebraska; south to Alabama and Louisiana.
Toronto; _Miss Currie._

2. OLIGONEMA BREVIFILUM _Peck._

PLATE XX., Figs. 5, 5 _a_.

1878. _Oligonema brevifila_ Peck, _Rep. N. Y, Mus._, p. 42.

Sporangia small, cylindric, dull ochraceous-yellow, sessile closely
crowded, sometimes superimposed, forming large, effused patches several
centimetres in extent; capillitium exceedingly scant, consisting of
nothing more than a few minute threads, very short, only three or four
times the diameter of the spore, smooth, or without any definable
sculpture, ochraceous; spore-mass dark ochraceous, under the lens the
spores are brighter, marked with reticulations much as in other species
of the genus, 10-12 mu.

Probably a variety of our No. 1, but constantly collected.

Separate, however, from the following also in co