) I
H !l
often situated in a forking of the branch, and generally in one of the uppermost
forks, subtended by a few short ramuli. Tetraspm-es prominent,
forming a whorl fround the joint, in the upper (but not ultimate) divisions
of the filament. Colour a dark purplish-red. Substance delicately membranaceous
and soft. In drying the plant closely adheres to paper, and
has a peculiar glassy lustre, especially in the colourless portions of the
thread.
A beautiful species, and a tolerahly definite one, considering
the genus to which it belongs ! It is known from C. nodosum
by its less patent branching, its more purple colour, and different
disposition of the tetraspores, besides minor characters,
more readily taken in by the eye than the ear. Sometimes the
branches are found quite smooth, and at other times every node
of the upper branches and ramuli is densely clothed with long,
flexible hairs, which appear to he the same pubescence that
Kiitzing describes, and on the presence of which he founds his
genus Trichoceras. At first, on noticing these hairs, abundantly
clothing a specimen sent by Miss Turner from Jersey, I was
disposed to regard them as a specific character, and to suspect
that I had before mo Trichoceras vilhsum of Kützing. Whether
this be so or not, I soon abandoned all thoughts of grounding
a species on the presence or absence of such hairs, for I found,
on examining numerous splendid specimens sent to me by Mr.
Boswarva and Dr. Cocks, that nothing could be more inconstant ;
branches from the same tuft differing in the degree of hairiness,
and specimens from the same locality, and identical in all other
characters, being some hairy, some perfectly smooth. Lastly,
on re-examining my original Dingle specimens, which had been
acknowledged by Kiitzing himself to be truly his C. strictum, I
found traces of similar pubescence. And such hairs are by no
means restricted to this species, but occur on C. rubrum, and probably
on most other species. They are, I suspect, organs of the
same nature as thè fibrilla of Polysiphonia, and if this be the
case we may expect to find antheridia on them.
Fig. 1. C e k a m iu m STKIOTÜM :—the natural size. 3. Portions of two filaments,
one hairy, the other smooth. 3. Part of a branch, with a/«TO«a. 4. Part
of a branch, with tetraspores in sitn. 5. Apex of a branch, partially clothed
with hairs. 6. A hair. 7. An articulation of the lower part of the filament
:—all the latter figures more or less highly magnijied.