Ser. RHoDOSPERME. Fam. Ceramiee. 
Piate CCXXXI. 
CALLITHAMNION POLYSPERMUM, 4. 
Gn. 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 ¢etraspores, 
scattered along the ultimate branchlets, or borne on little pedicels ; 
2, roundish or lobed, berry-like receptacles (favelle), seated on the 
main branches, and containing numerous, angular spores. CaLii- 
THAMNION (Lyngb.),—from xados, beautiful, and Gaynor, a little shrub. 
CaLLITHAMNION polyspermum; tufts globose ; filaments slender, delicate, 
loosely much-branched, irregularly divided below, distichously plu- 
mulate above; plumules long and narrow, simply pinnate; pinne 
short, simple, patent, acute, spine-like ; articulations of the branches 
with a very narrow coloured tube, four or five times as long as 
broad, of the ramuli short; tetraspores globose, lining the inner face 
of the pinne. 
CALLITHAMNION polyspermum, 4g. Sp. Alg. vol. li. p. 169. Harv. in Hook. 
» Br. Fl. vol.ii. p. 342. Harv. in Mack. Fl. Hib. part 3. p.214. Harv. 
Man. p.108. Wyatt, Alg. Danm. no. 140. Endl. 3rd Suppl. p. 34. 
CaLLitHaMNion Grevilli, Harv. in Hook. Br. Fl. vol. ii. p. 345. Harv. 
Man. p.110. Harv. im Mack. Fl. Hib. part 3. p. 215. 
CALLITHAMNION roseum, Grev. Fl. Edin. p.311 (not of Br. F.) 
CaLLITHAMNION purpurascens, Johust. Berw. Fl. vol. i. p. 240. 
PHLEBOTHAMNIUM polyspermum, Kitz. Phyc. Gen. p. 374. 
Has. On various Algz between tide-marks, frequently on Mucus vesiculosus 
and F. serratus. Annual. Summer. All round the coast. 
Groer. Distr. Atlantic shores of Europe. 
Derscr. Root discoid, small. Zufts globose, one to three inches in diameter, 
dense. Filaments capillary, excessively branched; stem zigzag, with short 
articulations, traversed by a few fibres but not thereby rendered opake, 
irregularly divided, and either somewhat bare or well furnished with alter- 
nate, secondary branches. Branches long and slender, zigzag, bearing a 
second or third series, the latter alternately plumulate with considerable 
regularity. Plwmules usually long and narrow, simply pinnate, or occasion- 
ally the upper part more compound. Pinne@ usually short, patent, subulate, 
sometimes recurved, in luxuriant specimens so far lengthened that the out- 
hne of the plumule becomes ovate. Articulations of the branches 4—5 times 
as long as broad, with a very narrow bag of endochrome; of the ramuli 
twice as long as broad, fully coloured. etvaspores usually lining the inner 
faces of the pinne, globose. avelle of large size, in dense clusters, 
bursting from the rachis of a distorted plumule. Occasionally the place of 
tetraspores is occupied by round bodies (antheridia? or rather viviparous 
tetraspores) formed of innumerable minute cells, strung together. Colour, 
WOl: 11. QE 
