1: 1:1
mthe
periphery the branches become many times thicker, and
form a small-meshed regular network, furnished with numerous
stout, acute, free tip s ; the free tips are simple, or once or twice
furcate; the entire capillitium is protruded elastically during
dehiscence; columella absent; spores globose.
Distinguished from Arcyria, its nearest ally, by the very
numerous free, pointed, simple or branched spines springing
from the tubes of the stout peripheral portion of the capillitium,
the meshes of which are much more uniform in size and shape
than in Arcyria. The present genus agrees with OpJiiofheca
in the presence of numerous free arms on the capillitium, but
in the last-named genus the free ends are not attenuated at
the point, but usually inflated, and furthermore the tubes of
the capillitium are of equal thickness throughout, and not of
two distinct types as in Heterotrichia.
H e t e r o t r i c h i a G a b r i e l l a e , Mass. (n. sp.) (figs. 203—207).
Sporangia densely crowded, becoming scattered towards the
margin of the cluster, cylindric-ovate, wall thin, smooth, even,
at first red, becoming yellowish-brown at maturity, upper portion
disappearing, leaving a small calyculus; stem much shorter
than sporangium, thin, filled with large cells; mass of capillitium
and spores yellowish-brown; threads of central portion
of capillitium about I'o g thick, with slightly raised rings or
short bands partly encircling the tube, almost colourless, threads
of peripheral portion bright-yellow, 3—6 g thick, forming au
even network, free arms of equal thickness to tubes of network,
40—60 g long; every part densely and uniformly covered with
warts or short bands, a few scattered elliptical swellings are
present on the tubes and spines; spores globose, smooth, 7— 8 g
diameter.
On wood. South Carolina.
(Type in Herb., Kew.)
Sent to Dr. Cooke by the late H. W. Ravenal, accompanied
by the following no te ;—“ Arcyria Qahriellae, n. sp. Primary
state red, becoming fuscous, closely congregated, elongated,
stipitate, peridia circumscised, upper part fugacious, spores
reddish fuscous. April 1850. S. C., H. W. R.
The species was considered by Cooke to be Arcyria Ucolor,
Berk.
Arcyeia, Hill (emended).
Sporangia regular, plasmodiocarp, or aethalioid, wall single,
dehiscingY-regularly or in a circumscissile manner, basal portion
persistent, columella absent; stem usually filled with large cells
which become smaller upwards and gradually pass into normal
spores; capillitium dense,usually becoming elastically elongated
and protruding during dehiscence, free, or the basal threads
attached to the inside of the stem, or attached at several points
to the lower, persistent portion of the sporangial wall, threads
combined to form a dense network with or without free ends,
ornamentation in the form of continuous ridges arranged in a
spiral, or prominent, plate-like half-rings or spines arranged in
a very open spiral, or wart-like spines scattered equally over the
entire surface of the threads.
Areyria, Rost., Mon., p. 270; Cke., Myx. Brit., p. 69; Saoc.,
Syll., vii., p. 425. _
HemiaTcyricc, Kost,, Mon., p. 261; Cke., Myx. Bnt., p. 6/ ;
Mass., Mon. Trich., p. 27; Saco., Syll.. vii., 1, p. 446.
The genus Hemiarcyria was founded by Rostafinski on those
species'of Areyria having continuous ridges arranged in a spiral
manner on the threads, as in the genus Trichia, and remodelled
Arcyria to include all those species having the threads ornamented
in any other fashion than by spirally arranged ridges.
I t is an open question as to whether ornamentation of the
capillitium threads is of generic value even if constant, as
supposed by Rostafinski, hut such is certainly not the case;
the two extreme characteristics overlap and are comhined in
several species. In some species of Hemiarcyria the spiral ridges
are accompanied by numerous spines, as in H. rubiformis and
H. smpula, whereas in H. melanopcziza, a Brazilian species, the
spines are abundant, and the spiral ridges present, but shadowy
in some individuals and entirely absent in others, consequently
‘’Mil