are gradually smaller ; in age the centre becomes more or less hollow. Substance
wlicn frcsli, cartilagiuous, but if kept long, becoming very gelatinous
anil slippery, giving out in frcsli water, considerable quantities of slimy
matter. Cohur yellowish brown, either drying to an olive, or retaining
much of its original hue.
Hitherto, in British works, the plant here figured has been
regarded as a species of Sporoclmm. It is now removed, according
to the views of all recent continental authorities, to the
Bictyotea, in which family it constitutes the type of a new
genus. If we compare its fructification with that of Aspero-
coccm, or of Punotaria, we shall be satisfied that its true place
in the system cannot be very far apart from these genera. The
difference, indeed, is more in the nature of the frond, and the
general habit, than in the fructification. From the true Sporochni,
one of which we have figured at PI. LVI. the fructification
of the present plant essentially differs, the position of the spores,
their form, and the nature of the filaments that accompany them,
being quite dissimilar.
The var. /3. of British authors is now regarded by Professor J.
Agardh as a distinct species, called by him Stilophora Lynglyei.
I have some hesitation in admitting it to the rank of a species
notwithstanding its peculiar character, and the great abundance
and uniformity of its production, wherever it occurs; and it has
been found from the south of Ireland to the Orkneys, everywhere
preserving the fistular stem, divaricated branches, and attenuated
ramuli. It is always found in deeper water than the normal
form, and always in land-locked bays, and these modifying causes
I have hitherto believed, produce the variations. It is, however,
at least a well-marked variety, and, as such, deserving of a figure
and description, both which I purpose affording it in a future
number of this work.
Fig. 1. S t i l o p h o r a r h i z o d e s :— tlie natural size. 2. Part of a branch. 3.
Transverse section of the same. 4. Section of a sorus. 5 . Spores -.— ail
more or less highly magnijied.
•hi
iii'