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loiio-, giving the frond an ovate outline, and bearing a second or tliird series
of lesser branches. In others, the main stem is once or twice forked, and
clothed throughout with short lateral branches of nearly the uniform length
of an inch ; and in others (as represented in our figure), the stem is irre-
R'ularly forked, the lateral branches more erect, simple or divided, more or
less fastigiate, and the general outbne of the tufts roundish. In all vai'ieties
the younger portions of the fronds are beset with more or less dense, haw-
like'jointed ramuli about two lines in length, and issuing ivitli out order
from all sides of the branch. Occasionally these are very few and the plant
becomes S. nudiuscula, of Kutzing, Tube occupying two thirds of the
breadth of the stem, divided into joints by transverse diaphragms, placed at
short intervals ; its waUs cellular, and the external surface reticulated.
Tetraspores elliptical, clustered round the bases of the ramuU. Favellæ
bi-lobed, or rarely tri-lobed. Colour a dull red, very frequently faded, and
yellowish white. Substance, of the stem cartilaginous, of the ramuli mem-
bnmaceous.
Tliis plant, wliicli is very local on tlie British coasts, although
found in considerable plenty in a few places, is interesting in a
geographical view, being a native of warm latitudes which reaches
to its northern limit in this country. Until very recently that Mr.
Ralfs discovered it on the Welsh coast, it had only been found
in Britain on the extreme southern shores. It is more plentiful
in the Channel Islands, and along the French coast, and abounds
in the Mediterranean ; but the finest specimens are found in the
Tropical ocean. In Britain it is very generally much discoloured,
being of a dirty grey or brownish cast, a deformity caused by its
growing in comparatively shallow water, and in places exposed to
strong sunshine.
A plant so widely dispersed is, as might reasonably be supposed,
subject to some variations of character, on which Kiitzing
lias proposed to found several distinct species. In the detailed
description I have noticed some of these variations, which do not
appear to me to be of specific value ; and in a very extensive series
of specimens from different localities I find innumerable intermediate
forms. The most distinct looking variety, (and it may,
perhaps, he admitted as a species) is found in Tasmania, and has the
ramuli pretty constantly whorled, and much denser than usual.
Fio-. 1. S p y m d t a H L A M E N T O S A TCfam/sAe. 3. A transverse section of the
stem. 3. Longitudinal semi-section of the same, 4. Branchlet with its
ramuli, bearing tetraspores. 5. Bamulus with tetraspores. 6. Branchlet
bearing/aw//«. 7. K favella. 8. Spores from the same ■.— all more or less
magnijied.
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