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R1VULARIA tuberculosa.
Tubercular Kivularia.
j b b
CRYPTOGAMIA Algce.
G e n , C h a r . Frond gelatinous, f i rm , destitute of an
external cuticle. Fructification among jointed filaments,
lodged in the substance of the frond.
S p e c . C h a r . Globose, unequally tubercular, concave,
sessile, green. Internal filaments repeatedly
branched, equal, obtuse, divaricated, entangled ;
their joints somewhat swelling.
Syn. Rivularia tuberculosa. Roth. Catal. v. 3. 341.
C o l l e c t e d in fresh water near Henfield, Sussex, in September
last, by Mr. W . Borrer, to whom we are obliged for
the reference to Roth.
This is allied to the species figured in our 14th vol. t. 968,
under the name of Ulva pruniformis given by Linnaais, but it
is a true Rivularia. See v. 25. t. 1797. The present appears
to differ from that in its tuberculated surface, caused by the
clustering mode of growth of the internal, much branched
and divaricated, filaments. It is a larger plant than R. ele-
gans, t. 1797, and hollow, though filled with watery pulp,
within.