M. Gaillon has ai-rangecl this species under the genus Polyides ; but
the nemathecia have no real affinity with the peculiar fructification of
Polyides lumbricalis, which contains tubercles of distinct seeds. The
nemathecia of Gigartina Griffithsiæ appear to divide at the articulations,
commencing at the apex, as Agardh observes, and joint by joint
to separate into oval red seeds or granules.
Mrs Griffiths is the discoverer of this Alga, and her name was deservedly
bestowed upon it by Mr Dawson Turner.
4. G ig a r t in a p l ic a t a .
Frond horny rigid cylindrical filiform equal entangled, the branches
numerous horizontal mostly secund, warts (nemathecia) oblong embracing
the stem.
Gigartina plicata, L a in o u r . E s s a i, p . 48. L y n g b . H y d r o p h . D a n . p . 42. G r e v . P I. E d in .
p . 289.
Sph(B7-ococcus plicatus, A g . S p . A lg . v . 1. p . 313. S y s t. A lg . p . 234. S p r e n g . S p . P I.
V. 4. p . 339.
Fucus plicatus, H u d s . F I . A n g . p . 589. S t a c k h . N e r . B r i t . p . 23. t . 7. T u r n . S y n . F u c .
p . 323. H i s t F u c . 1 . 180. S m . E n g . B o t. 1. 1089.
Scytosiphon Hippuroides. L y n g b . H y d r o p h . D a n . p . 63. t . 14.
H a b . On rocks in the sea. Perennial. Very common.
Root a small disk. Fronds numerous, tufted, wiry and entangled,
three to ten inches long, about as thick as a hog’s bristle, cylindrical,
equal in thickness or nearly so from the base to the apex, branched
dicbotomously or irregularly, the whole set with horizontal ramuli of
various lengths, scattered or crowded, mostly pointing in one direction,
but sometimes to every side, obtuse at the apex. Occasionally
the ramuli bear a series of still smaller ones, also generally secund.
Fructification unknown, except in the form of nemathecia, which
produce small, elliptical or oblong, dark coloured warts, embracing
the frond, and composed entirely of parallel obscurely articulated filaments.
Substance horny, rigid and wiry. Colour blackisli purple,
changing, as it undergoes decay, to reddish brown, yellow, and at
length to white. In drying it does not adhere to paper.^
In addition to the warts composed of the articulated filaments {nemathecia,
Ag.), others are very common, of a roundish form, some
very minute, others larger and resembling the base of a broken branch :
these have no connection with fructification, as far as may be ascertained
from their structure, in which they do not differ from the rest
,of the frond. The plant is liable to vary in its mode and degree of
branching; the summit is generally crowded with ramuli, but in some
larger varieties the branches are elongated for two or three inches in a
simple form. The whole is so entangled, so tough and wiry, that
there is little chance of its being mistaken for any other species.
G e n u s XL. GRATELOUPIA, Ag. Tab. XVI.
G e n . C h a r . Frond cartilagino-membranaceous, plane, sometimes
pinnated with branchlets, or fringed with foliaceous
processes. Fructification; minute aggregated tubercles
furnished with a pore, and containing a mass of free elliptical
or roundish seeds.
Obs, Of this genus I can say little from my own experience. It is
named by Agardh in honour of Dr Grateloup, a French naturalist,
who has paid particular attention to the Algoe. It includes but few
species. The Fucus ornatus of Linnæus (erinaceus, Turner), and Gra-
teloupia hystrix, first described by Agardh, belong to it. The root is
scutate. The nature of the fructification is well detailed in Plate xxvi.
of Mr Dawson Turner’s work ; and the opinion of that gentleman is
strongly corroborative of the propriety of what Agardh has done. He
observes, in his description of his Fucus erinaceus, “ that it has in
external appearance no affinity to that of the globuliferous Fuci, and
seems rather to approach to that of the Fuci proprii, from which the
plant itself is in substance and habit as widely removed as possible.”
The fructification is also equally peculiar. The two exotic species
mentioned above are natives of the Cape of Good Hope.
I. G r a t e l o u p i a f i l i c i n a . Tab. XVI.
Frond linear attenuated simple or divided irregularly pinnated with
ramuli attenuated at each extremity.
Grateloupia filicina, A g . S p . A lg . v . 1. 'p . 224. S y s t. A lg . p . 241. S p r e n g . S p . P I . v . 4.
p . 334.
Delesseria filicina, L am o u r . E s s a i, p . 38.
Fucus filicinus, W u l f . i n J a c q . C o ll. v . 3. p . 157. t . 15. f . 2. T u r n . H is t. F u c . 1 . 150.
H a b . On rocks and different submarine substances. Perennial?
Producing fructification in the autumnal months. Sidmouth and Ilfia-
combe. Miss Cutler.