in Donegal; which account, though its usual habitat is in
rivers, is confirmed by the occurrence of the Alga in Zealand
in a similar position. Its claim however to admission into our
Flora is now set at rest by the discovery of it in great abundance
in the Thames at Walton by Mr. McIvor; and Mr.
Borrer, to whom I am indebted for a specimen, has lately
found it in the same locality. It can scarcely, I think, be
doubted that Dr. Harvey is quite right as to its affinities,
which are with Batrachospermum.
Frond growing on wood or other substances, attached by a
little scutate disk, or, as in Mr. Borrer’s specimens, clasping
by its creeping base the stems of Fontinalis; from a few inches
to three feet or more in length, dark olive-green, changing to
purple when dry, gelatinous, much-branched, consisting of a
dense central thread (composed of much-branched radiating
filaments with short obtuse articulations, some of which are
terminated by pyriform spores) and clothed with regular patent
simple or branched flocci, consisting of articulations many
times as long as broad, and giving off principally near the
base on short ramuli solitary, binate or ternate pyriform
spores, which are either naked below or furnished at their base
with a whorl of two or three threads. The threads when
placed in diluted spirits of wine become wrinkled and the
endochrome contracts.
Fig. 1, portion of branch magnified; fig. 2, section of
branch magnified; fig. 3, more highly magnified section showing
spores or sporoform bodies springing immediately from
the inner substance; also the usual sessile fruit; fig. 4, stipi-
tate capsules on the investing threads.—M. J. B.