Morgan, _l. c._

Sporangia crowded or heaped in scattered clusters; peridium thin, golden
yellow, adorned with intricate radiating veinlets capillitium of threads
more or less branched, attached below, free above, the surface to the
very tips venulose, interrupted with rings or fragmentary spirals, the
apices bulbous and obtusely conical; spore-mass yellow, spores by
transmitted light bright yellow, covered by a network of interlocking
plates, as in _T. favoginea_, globose, 14-16 mu.

A curious form, related to _Hemitrichia_, much as _Oligonema_ is to
_Trichia_. Related to both the genera first named, but distinct, in the
peculiar sculpture, from _Hemitrichia_, and from _Oligonema_ in that the
threads are not entirely free. Professor Morgan's original
determination, founded on Ohio materials is confirmed by material sent
us by Professor Underwood from Alabama.

=3. Trichia= (_Haller_) _Rost._

1768. _Trichia_ Haller, _Hist. Stirp. Helv._, III., p. 114, in part.
1875. _Trichia_ (Haller) Rost., _Mon._, p. 243.

Sporangia distinct, sessile or stipitate; capillitium of distinct
elastic threads, free acuminate at each end, yellow or more rarely
reddish or brown; spores generally yellow.

The trichias are easily recognized among their kind by their beautiful
spirally wound, elastic capillitial threads, the _elaters_; these are
entirely free, about 3-4 mm. in length, simple or only rarely branched,
and generally acute at each extremity. The spiral bands, sometimes
called _taeniae_, are generally very uniform in thickness, distance from
each other, and pitch, and in many species are further reenforced by
minute longitudinal plications running from one spiral to the next.
Furthermore, the spirals may be smooth or spinulose the elater uniform
throughout or enlarged betimes by nodes and swellings. Taken altogether,
the trichias with the species of the genus next following exhibit the
highest degree of differentiation attained by the Myxomycetes.

Most of the earlier authors, including Haller, used the generic name
_Trichia_ to cover a variety of forms. It is here used with the limits
sketched by De Bary in 1859 and 1864 (_Die Myxomyceten_), and followed
more exactly ten years later by his pupil, Rostafinski.

=Key to the Species of Trichia=

_A._ Sporangia, in typical cases at least, wholly sessile.

_a._ Gregarious; hypothallus none.

i. Peridium brown or reddish brown.

O Ela