Root minutely scutate. Fronds from two or three inches to a foot
or more in length, filiform, cylindrical and tubular, varying from the
fineness of a hair to a line in diameter in the main stem, much
branched: branches arising on all sides throughout the whole frond,
very unequal in point of length, some a few lines, others many inches,
irregularly subdivided, beset with numerous, very short, spreading,
often curved ramuli, all attenuated toward the extremity. Fructification,
small clusters of roundish granules occupying some of the reticulations.
Substance tender and inembranaceous. Colour varying
from a very deep to a pale yellowish green. In drying, it adheres
imperfectly to paper, and does not change colour.
Var. g is distinguished for its pale colour, its erect mode of growtii,
long and almost undivided branches, and the small number of minute
ramuli. In this variety, the granules of the fructification are to be
distinctly seen. It looks like a distinct species, but I hardly know
what to seize upon for a good specific character.
Var. y (the Ulva ramulosa of English Botany) has a deep green
colour, and its branches much attenuated ; they are beset on every
side with ramuli, half a line to two lines in length, some of them
curved upwards, some downwards. The figure in “ English Botany ”
is a very inadequate representation of the plant, as it is sometimes
above a foot in length, and the brandies are generally quite capillary.
The structure of this species is an irregular somewhat quadrate
kind of reticulation, but much more distinct than that of Enteromorpha
compressa.
4. E n t e r o m o r p h a L in k ia n a .
Frond cylindrical, tubular, filiform, reticulated, pellucid, of a very
pale green colour, membranaceous (rigid when dry), much branched,
branches attenuated.
Hab. In the sea. Annual. Summer. Coast of Appin, Captain
Carmichael.
Root a minute disk. Frond six to twelve inches in length, filiform,
cylindrical, tubular, inflated, rising with a main stem about one line in
diameter, on all sides of which, and along the whole lengtli, the
branches are inserted: branches two to six inches long, smaller in diameter
than the stem, between erect and spreading, set with a second
series one or two inches long, which, in their tum, bear a third, which
are quite capillary, all of them much attenuated toward the extremity.
The structure distinctly reticulated, the reticulations roundish, but
angular. Fructification, three to four subglobose granules within
many of the reticulations. Substance membranaceous, but firm and
somewliat cartilaginous when dry, adhering very imperfectly to paper.
Colour a very pale yellowish green.
This species, which appears to be very well distinguished by its
comparatively rigid substance, I have dedicated to the celebrated naturalist
whose name for the present genus I have adopted. It is upon
this species in particular, that Myrionema strangulans (Crypt. FI.
t. 300.) is parasitic. The fructification is remarkably conspicuous under
the microscope, and very evidently composed of three or four clustered
granules.
O r d e r X I I .— S IPH O N EÆ .
Plants found in the sea, in fr e sh water, or on damp ground, 8fc.;
o f an herbaceous green colour. Frond either composed o f
memltranaceous, filiform, continuous, simple or branched tubes,
or formed o f a combination o f similar tubes, and then presenting
a lax spongy body o f various forms, crustaceous, globular,
cylindrical or fia t. Fructification, vesicles {Coniocystæ,
Ag.) produced on the outer surface o f the tubes filled with a
darh green granular mass.
In Botrydium, the entire plant is little more than a hollow
green globule with a radicating tu ft o f fibres ; the fructification
may be considered as unknown. Agardh looks upon the
holloiv globule as a vesicle.
Ge n u s LI. CODIUM, Stackh., Ag. Tab. XIX.
Ge n . Ch a r . Frond spongy, dark green, (crustaceous, globular,
cylindrical, or flat), composed of an interwoven mass