P l a t e CCXCVI.
CALLITHAMNION PLUMA, Ag.
G e n . C h a r . Frond rosy o r b row n ish -red , filam e n to u s ; stem e ith e r opake
a n d c ellu lar, o r tra n s lu c e n t an d jo in t e d ; b ran ch e s jo in te d , o n e -tu b e d ,
m o s tly p in n a te (rarely d ichotomous o r i r r e g u l a r ) ; d issep im en ts
h yaline. F ru it o f two k in d s , on d is tin c t p l a n t s ; 1, e x te rn a l tetraspores
s c a tte re d along th e u ltim a te b ra n c h le ts, or b o rn e o n little
p e d ic e ls ; 2, ro u n d ish , or lobed, b e rry -lik e receptacles (fa v e lla ) sea ted
o n th e m a in b ran ch es , a n d co n ta in in g n um e ro u s a n g u la r spores.
C a l l i t h a m n i o n (L y n g h ),— ivym. koWos, beauty, an d Bapviov, a little
C a l l i t h a m n i o n Pluma ; stems rising from creeping filaments, erect, sub-
simple, or alternately branched; branches naked below, the upper
half pinnated with short, erect, closely set, opposite ramuli ; articulations
from two to four times as long as broad ; tetraspores globose,
either terminating shortened pinnules, or placed on little stalks near
the base of the pinnule.
C a l l i t h a m n i o n Pkma, Ag. Sp. Alg. vol. ii. p. 162. Ilarv. in Hook. Br. M.
vol. ii. p. 840. Harv. in Mack. FI. Hib. part 3. p. 217. Harv. Man. ed. 2.
p. 173. P. Bot. Suppl. Pndl. 3rd Suppl. p. 3^. Kütz. Sp.Alg.
p. 647.
C a l l i t h a m n i o n Plumula, S pusUlum, Lyngb. Hyd. Pan. p. 127. t. 39.
C e r a m i u m Pluma, Ag. Syst. p. 132.
C o n f e r v a Pluma, Pillw. Conf. p. 119. tab. P.
H a b . Parasitical on the stems of Laminaria digitata, rather rare. Annual.
Summer. Bantry Bay, Miss Hutchins. Malbay, W. H. H. Appin,
Capt. Carmichael. Probably overlooked on other parts of the coast.
G e o g r . D i s t e . Atlantic shores of Europe.
D e s c e , Forming velvety patches of some extent on the surface over which it
spreads. Pronds nsing from prostrate, creeping filaments, erect, from a
quarter to half an inch or rather more in height, very slender, simple, or
furnished with alternate or opposite, very erect branches : sometimes, in
luxuriant specimens, almost bushy. Branches naked in their lower half,
closely feathered above with opposite, erect, simple, straight ramuli, a pah
of which issue from every articu ation of the branch : ramuli, from suppression,
sometimes alternate or secund. Articulations of the stem from three
to four times longer than broad, of the branches shorter ; those of the
ramuli frequently scarcely exceeding their diameter in length. Tetraspores
globose, either borne on short, proper pedicels, which rise, singly or in
pairs, near the base of the pinnules, or terminating a shortened pinnule :
Î
" iii