Ser. RHODOSPERME. Fam. Ceramiee. 
Prats CCLXII. 
CALLITHAMNION BYSSOIDEUM, 4rz. 
Gun. Cuar. Frond rosy, or brownish-red, filamentous; stem either opake 
and cellular, or translucent and jointed ; branches jointed, one-tubed, 
mostly pinnate (rarely dichotomous or irregular) ; dissepiments hya- 
line. Fruit of two kinds on distinct plants; 1, external ¢e¢raspores, 
scattered along the ultimate branches, or borne on little pedicels ; 
2, roundish or lobed, berry-like receptacles (/avel/z), seated on the 
main branches, and containing numerous, angular spores. CaLtt- 
THAMNION (Lyngb.),——from kaos, beauty, and Oapmor, a little shrub. 
CaLLITHAMNION dyssoideum; stems exceedingly slender, flaccid, and bys- 
soid, much divided; branches lanceolate in outline, 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, ellip- 
tical ; favellee binate, subterminal. 
CALLITHAMNION byssoideum, 4rn. MSS. Harv. in Hook. Br. Fl. vol. ii. 
p. 342. Wyatt, Alg. Damn. no.185. Harv. Man. ed. 1. p. 107. 
Has. On several Algz, in tide-pools near low-water mark; on Codiwm 
tomentosum, especially. Annual. Summer. Whitsand Bay, Dr. 
Jacob. Devonshire, Mrs. Griffiths. Salcombe, Mrs. Wyatt. Ply- 
mouth, Rev. W. Hore and Dr. Cocks. Portaferry, Strangford Lough, 
Mr. W. Thompson. Dublin Bay, and Cork Harbour, W. H. H. Not 
an uncommon species. 
Groer. Distr. Not noticed out of Britain. 
Descr. Filaments extremely slender, as fine as cobwebs, densely tufted, from 
two to four inches long, excessively branched in’ a decompound-pinnate 
manner, all the divisions alternate and distichous. The whole frond, 
when displayed on paper, has an ovate or pyramidal outline, the lower- 
most 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. etraspores elliptical, 
sessile, rather large, borne on the sides of the pinnules, towards the base, 
one or two, rarely more, on each pinnule. uvelle binate, generally termi- 
nating 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. 
PLL LLL LILI LILLIE LILI PLP LE 
