r U C U S BALTICUS.
D w a rf ribless Ftccus.
C la s s a n d O r d e n C R Y PTO G AM IA ALGJE, Linn N a t . O rd . ALGM, Be Cand,
Grev.
GENERIC CHARACTER.
“ Receptacula tuberculata; tuhvTculis pertusis, includentibus gkmeruhs Jibra-
rum capmhrumqm massx mucom fh ro sK immersos.’’—A g. Radix scutata.
Frons aut Jiliforms out plana. Color olivácea.
Receptacles tuberculated. Tubercles -with a pore, containing fibrous bodies
of a round form, along with capsules, immersed in a mucose-fibrous
mass— Root scutate. Frond either filiform or plane. Colour olivaceous.
SPECIFIC CHARACTER.
Fu cu s balticusj fronde plana, minuta, subcostata, angustissime lineari, dicho-
toma, integerrima, evesiculosa, m a r in e subtuberculata.
F. frond plane, minute, nearly without any midrib, extremely narrow, linear,
dichotomous, entire, without vesicles, somewhat tuberculated at
the margin.
Fu cu s balticus, Ag. Dec. No. 21.—Aw. Bot. t. 5l6. figs. a, b, c, e.
Fucus vesiculosus, var. subcostatus, Ag. Syn. p. 5.—Lyngb. Hydroph. p. 3.
Ag. Sp. Alg. V. 1. p . 91.
Hab. Sea shores. A t Dunstafihich Castle, nearly’ at] high-water mark,
and on the island o f Kerera, Mr M a u g h a n . Appin, Captain C a rm ic
h a e l . Island of Arran, D r H o o k e r .
Root, a minute scutate base. Frond 1-2 inches in height, not 2 lines in
breadth, linear, plane, nearly ribless, or found to be very obscurely furnished
with a midrib when held between the eye and the light, 2 -4
times dichotomous, opake, olivaceous green towards the extremity, below
reddish or dark b row n ; the margin somewhat tuberculated, which
appearance is evidently caused by the pore-like orifices from which the
white confervoid filaments issue, and which are so numerous on the
surface of the frond in Fucus vesiculosus, being here found at the margin.
There is not the least trace of vesicles or fructification upon any
of the numerous specimens in my possession.
VOL. IV.