r ;
’I"
•i!
il
O r d e r IV . S P O R O C H N O ID E Æ .
Plants all marine, o f an olivaceous or yellowish green colour,
not changing to black in drying ; o f a cartilagino-membrana-
ceous substance, becoming flaccid almost immediately after exposure
to the air, in some cases acquiring under such circumstances
a verdigris green colour, and then possessing the property
o f rapidly decomposing other delicate Algae in contact with
them. Frond with a scutate [rarely tomentose) root, fla t,
compressed, or cylindrical, with distichous (rarely irregular)
branches, and bearing in most species at some period o f their
growth little pencil-like deciduous tufts o f fine green filaments.
Fructification, as fa r as it is known, composed o f club-shaped
moniliform radiating filaments, either forming sessile warts,
or arranged concentrically in little stalked club-shaped bodies
terminated by pencils o f delicate fibres.
G e n u s IX. DESMARESTIA, Lamour. Tab. V.
G e n . C h a r . Frond cartilaginous, plane or compressed, distichously
branched, while young furnished with marginal
deciduous tufts of fine green filaments, the branches
set with marginal spines.
O bs. This genus was dedicated by Lamouroux to the celebrated
French naturalist and professor of zoology, A. G. Desmarest. I have
adopted it, with the exclusion only of Fucus viridis of authors.
Agardh, it appears, rejected Lamouroux’s name for one of bis own,
intending, at the same time, to bring together a number of other
plants. In strict justice the older name should have been sustained
by the learned Swede. Why Lyngbye should also have substituted a
third name, that of Desmia, I am at a loss to conjecture. The fructification
is unknown, but the habit of the species is vastly different
fi-om that of the other Spo ro ch n o id eæ .
1. D e s m a r e s t ia l ig u l a t a . Tab. V.
Frond plane membranaceous with a faint midrib tri- or quadri-pin-
nate, the pinnae and pinnulæ opposite linear-lanceolate attenuated at
the base.
Desmarestia ligulata, L am o u r . E s s a i, p . 25.
Sporochnus ligulatus, Ag . S p . Alg. v . 1. p . 158. S y s t . A lg . p . 261. G te v . F I. E d in . p . 207-
S p r e n g . S p . P I . v . 4. p . 330.
Desmia ligulata, L y n g b . H y d r o p h . D a n . p . 33. t . 7.
Fucus ligulatus, L ig h t f . F I . S c o t. p . 946. t . 29. T u r n . S y n . F u c . p . 99. H is t. F u c . t . 98.
Sm . E n g . B o t. t . 1636.
H a b . in the sea, usually in deep water. Annual. Summer. Frith
of Forth, Lightfoot. Orkney Islands, Rev. C. Clouston. Near Hastings
and in Northumberland, Hudson. Common in deep waters in
Cornwall, Stackhouse. Lizard Point and Kynance Cove, Mr E.
Forster junior. Near Abergele, Mr Grijfith. Exmouth, Weymouth,
and Portland Island, Goodenough. Oystermouth and Caswell Bay,
Dilluiyn. Yarmouth beach, Mr Wigg. At Corton and Gunton, Suffolk,
Mrs Fowler. Torquay and Sidmouth, Mrs Griffiths.
Frond two to six feet in length, cylindrical, and as thick as a crow-
quill at the very base, soon becoming plane, one to three lines wide,
attenuated at the extremity, when fresh exhibiting a faint midrib, pinnated
throughout its whole length : the pinnae three inches to a foot
or more long towards the base, and in large plants bearing three eleven
four other sets of pinnulæ, each smaller than the preceding one,
all of them attenuated at the base and apex, and furnished with little
marginal spines. The little pencils of filaments are produced from the
axils of the spines, and soon fall off.
Substance at first slightly elastic, but immediately becoming flaccid ;
when very young it adheres to paper in drying, afterwards not at
all. Colour while growing, glossy olive or greenish brown.
Many of the specimens of this strikingly beautiful Alga, which I
have received from my friend the Rev. Charles Clouston, who gathered
them in the Orkney Isles, tally exactly with Mr Turner’s var. y dila-
tata, the frond being nearly four lines broad, the pinnulæ elliptical, and
supported upon short setaceous stalks. It is therefore a native of the
northern as well as of the more southern seas.
Ml
'i;