P l a t e CCLXII.
CALLITHAMNION BYSSOIDEUM, A m .
G e n . C h a e . Frond rosy, or brow n ish -red , filamentous ; stem e ith e r opake
a n d c ellular, or tr a n s lu c e n t and jo in te d ; b ran ch es jo in ted , on e -tu b ed ,
mostly p in n a te (rarely dichotomous or irreg u la r) ; dissepiments hy a line.
F ru it of two k in d s on d is tin c t p la n ts ; 1, ex te rn a l tetraspores,
sca tte re d a lo n g th e u ltim a te b ran ch es, or b o rn e on little pedicels ;
2, ro u n d ish or lobed, b e rry -lik e receptacles {favellæ), seated on th e
m a in branches, an d co n ta in in g num e ro u s, a n g u la r spores. C a l l i -
THAMNION {Lyngb),— from koW oç, beauty, an d Sapriov, a little shrub.
CALLITHAMNION byssoideum ; stems exceedingly slender, flaccid, and byssoid,
much divided ; branches lanceolate in outbne, virgate, set with
numerous long, slender, flexuous, pinnate or subbipinnate plumules ;
articulations of the branches eight times, of the ramuli four times as
long as broad ; tetraspores, one or two, sessile on the pinnules, eUiptical;
favellæ binate, snbterminal.
O a l l i t h a m n i o n byssoideum. A m . MSS. Harv. in Hook. Br. M. vol. ii.
p. 342. Wyatt, Alg. Damn. uo. 185. Harv. Man. ed. 1. p. 107.
H ab. On several Algse, in tide-pools near low-water mark; on Codium
tomentosum, especially. Annual. Summer. Whitsand Bay, B r.
Jacob. Devonslure, Mrs. Griffiths. Salcombe, Mrs. Wyatt. Plymouth,
Fev. W. Hore and B r . Cocks. Portaferry, Strangford Lough,
Mr. W. Thompson. Dublin Bay, and Cork Harbour, W. H .H . Not
an uncommon species.
G e o g k . D i s t k . Not noticed out of Britain.
D e s c k . Mlaments extremely slender, as fine as cobwebs, densely tufted, from
two to four inches long, excessively branched in a decompouud-pinuate
manner, aU the divisions alternate and distichous. The whole frond,
when displayed on paper, has an ovate or pyramidal outfine, the lowermost
branches being longer than the upper ones; each individual branch is
narrow-lanceolate, when taken in connection with the plumules with which
it is clothed. These plumules are slender, and flexuous, simply or doubly
pinnated, laxly set, with few and distant pinnules; the latter very long,
and destitute of ramuli or lateral processes. Articulations of the stem and
branches of great length, 6-8 times longer than broad, destitute of internal
veins, except in the lower part of the stem; articulations of the ramuli at
least four times as long as broad, but often more. Tetraspores elliptical,
sessile, rather large, borne on the sides of the pinnules, towards the base,
one or two, rarely more, on each pinnule. Pavellm binate, generally terminating
truncated branches. Colour, a fine rosy lake, with a slightly purple
or sometimes brown hue. Substance exceedingly tender and gelatinous,
closely adhering to paper in drying.