mary ones, exceedingly short and irregular, and issue from
the main filaments almost at right angles, and by their non-
moniliform appearance. In drying, also, it shrinks considerably.
I t is a well marked, but apparently not an uncommon
species. I am not able to refer it to any described hy Bory.
IMy specimens were met with during the summer in a rapid
part of the river Lea, near Waltham Abbey, attached
to piles of wood, which they almost covered. The length
of some of them reached to four inches; their great size,
the elegance of their movements, and their dark colour,
at once struck me, and made me desirous of securing specimens,
which it was not easy to do in consequence of the
depth at which they grew. I succeeded, however. In obtaining
a few at the imminent risk of immersion.
9. B atrachospermum proliferum Hass.
Plate L X I I I . Fig. 1.
Char. Frond grey, branches irregular, divaricate, beset
with short ramuli, which are pinnate. Whorls o f the
stems approximate, compressed, almost confused, in the
pinnate branches, subdistant, distinct, formed o f very few
filaments.
Batrachospermum moniliforme, B . proliferum, Carmichael.
Hab. Appin : Captain Carmichael.
I have seen but one specimen of this curious and Interesting
species, for an examination of which I was indebted
to Mr. H a rv e y : not the slightest doubt, however,
remains on my mind of its distinctness; it is certainly no
less distinct than rare. Captain Carmichael, to whom algologists
are deeply indebted, for numerous additions to both
the marine and freshwater divisions of the Algae, and whose
powers of observation were of a very high order, thus in his
MS. describes the plant in question. “ Frond, solitary or
in small clusters, one or two inches long, irregularly branched;
branches divaricate, curved or flexuous, opaque and very
dark coloured, beset Avith short ramuli, Avhich issue out from
tlie 'jo in ts among the wliorls of eccentric filaments, and are
themselves beset Avith Avhorls; colour g r ey .”
10. B atrachospermum rubeum Hass.
Plate XV. Pigs. 2, 3.
Char. Filaments much branched. Branches divaricate, alternate,
ramuli broad, expanded. Whorls o f the stems spherical,
distinct, subdistant, large, those o fth e branches
altogether confused.
Batrachospermum moniliforme var., Penzance, June, 1839 ;
Mr. Ralfs.
Tins IS one of the most curious, as well as distinct species
of the genus. I have seen but a single specimen of the
plant, but this is quite sufficient to establish it as a species.
This specimen was sent to me, amongst other good things, by
my friend Mr. Harvey, and belongs to the Herbarium of
I iin ity College, Dublin, to which Mr. Harvey, I believe,
has generously presented the whole of his collection of Algæ.
Batrachospermum ruhrum might possibly be mistaken for
Thorea ramosissima, on account of its mode of ramification, its
colour, which is b rig h t red, and, above all, th e expanded
branches, which are so like those of T. ramosissima, th a t if
it Avere no t for th e whorls on th e main stems, the species
mig h t readily be referred to th e genus Thorea, an error
Avhich even a microscopic examination of th e p lan t Avould not
a t once remove. I f one o f the Avhorls be submitted to the
microscope, it Avill be found to be composed, in p art, o f
slender filaments slightly beaded, and, in p art, o f other still
more slender threads, Avhich are cylindrical, and from Avhich
the first set of filaments would appear to arise, and both of
which are mixed to g e th e r ; and again, if a portion o f one of
th e branches be examined from Avhich th e Avhorls have dis- ■
appeared, it will be seen to be composed almost entirely o fth e
exceedingly minute, and occasionally branched threads, with
he re and th ere attached to them a single pyriform cell (see
^o" which is to be regarded eith e r as th e rudiment of the
I