The English flora - SeaweedAfrica

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Rivularia] ALGiE GLOIOCLADE^. 393
Ag. Syst. Alg. p. 26.— " Oscillatoria terpens, Bvry" (Arnott,
MSS.).
On rocks and stones, in streamlets and the borders of subalpine
lakes.— " Fronds one-fourth or half an inch in diameter, circular, slightly
convex, sometimes greenish but oftener of a dark chestnut colour. M-
ter a time they run together into a flat spongy crust of indefinite size.
On the smooth face of a rock, exposed to the trickling of water, I found
a connected sheet of it, upwards of a foot in diameter. When broken,
the crust appears zoned within, so as to indicate the age of the plant,
each zone being equal to a year's growth. At this stage, it is always
more or less stony, from the absorption of calcareous matter." Carm.
MSS.
7. R. granidifera, Carm. (gramdiferous Rivularia); frond
large convex becoming hollow underneath fleshy lubricous
brownish-olive, often including stony particles, (never petrified.)
Linkia dura, y. Crustacea, Lyngb. Hgdroph. Dan. p. 197?
On cliffs exposed to the trickling of water, common. " Annual,"
Capt. Carm'uhael.—" Fronds from a line to half an inch in diameter,
often confluent, convex and at length concave underneath, fleshy, dusky,
olive-green and extremely slippery. Filaments rather thick, repeatedly
dichotomous. In the substance are generally enclosed a number of
stony particles. This species comes nearest in size and form to 7^.
calcarea; but is never, like that, petrified with calcareous matter ; the
filaments are also much thicker and more decidedly branched ; and it is,
moreover, an annual plant, whereas the other exists for several years."
Carm. MSS.
8. R. crusldcea, Carm. (incrusting Rivularia); crust very thin
widely spreading, filaments attenuated at the base fastigiately
branched above the middle olive-green.
" On rocks, exposed to the spray of cascades in the hill-streamlets,"
Cap/. Carmiehael.—" Crust of no determinate extent, extremely thin and
slimy, black. Filament* one-fourth of a line in length, attenuated at
the base, fastigiately branched above the middle, of an olive-green
colour." Carm. MSS.
Sect. 2. ( Scytochloria, Harv.) : frond gclatinoso-coriav, >/ lobed and plaited often bullated lubricous
ihining deep-green, filaments simple or psendo-branched. Ag.
Syst. Alg. p. 25. Scytochloria nittda, Harv* MSS,— Rivularia
bullata, Berh. Alg. U 2./ 1.
On rocks, in the m;i. Torquay, Mrs, Griffiths. Miltown Bfalbay,
jr. //. Hni vru.— Frondt subfoliaceous, tremelloid, tufted or gregarious,
much lobed, the lobes sinuous j in a young state, compressed, and tilled
with gelatine; in age becoming bullated and hollow ; from half an inch
to :m null and half in diamet ST. Colour ;i deep but \cr\ vi\ id olive--! ten,
lubricous and subgelatinoua to the touch. Substemce firm, elastic, not
easilj lacerated. Filamenti either simple or pseudo-brancbed, subtor-
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