Ser. RHopOsPERMES. Fam. Ceramieae. 
Pirate CCLXIX., 
CALLITHAMNION THUYOIDEUM, 4%. 
—— 
Gen. Caan. 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 hyaline. 
Fruit of two kinds, on distinct plants; 1, external ¢etraspores, scat- 
tered along the ultimate branchlets, or borne on little pedicels; 2, 
roundish or lobed berry-like receptacles (/avel/e) seated on the main 
branches, and containing numerous angular spores. CALLITHAMNION 
(Lyngb.), from xdddos, beauty, and Oapriov, a little shrub. 
CaLLITHAMNION thuyoideum; stem capillary, undivided, set with alternate, 
distichous, repeatedly pinnate branches, with a narrow lanceolate 
outline; branches furnished with bipmnate or tripinnate plumules; 
articulations of the branches 2-6 times, of the pimnules about twice 
as long as broad; tetraspores borne on the tips of the ultimate 
pinnules. 
CALLITHAMNION thuyoideum, Harv. in Hook, Br. Fl. vol.ii. p. 346. Harv. 
deen. ed. F. p.1ll.- - 
CALLITHAMNION thuyoides, 4g. Sp. Alg. vol. iti. p.172. ‘Endl. 3rd. Suppl. 
p. 34. Kitz. Sp. Alg. p. 645. 
CALLITHAMNION tripinnatum, Harv. in Hook. Br. Fl. vol.ii. p. 346 (not of 
Agardh). Wyatt, Alg. Danm. no. 186. 
. ConFeRva thuyoides, H. Bot. t..2205. 
Has. On rocks, near low-water mark, rare. Annual. Spring and Summer. 
Yarmouth, Mr. Borrer. Plymouth, Mr. Icona, &c. Pier, Torquay, 
Mrs. Griffiths. Falmouth, Miss Warren. Ilfracombe ; and Bracelet 
Bay, Swansea, Ur. Ralfs. Wicklow, W.H.H. Portaferry, Mr. W. 
Thompson. Roundstone, Mr. Mec.Calla. - 
Geroer. Distr. British Islands, and Atlantic coast of France. 
Descr. Root a minute disc. Fronds one to three inches long, densely tufted, 
perfectly distichous, with an ovate or flabellate outline. Stem mostly 
undivided, closely pinnated through its whole length with alternate, very 
patent branches, the lowest of which are longest, the rest gradually 
diminishing to the apex. These primary branches have a lanceolate outline, 
and are, with great regularity, pinnated with linear-lanceolate plumules, 
one rising from every articulation, and turned alternately to the right or 
left; the lowest plumules very short, the upper gradually longer and more 
compound, to the middle of the branch, thence gradually shortening to- 
wards its apex. -Plumules bi- tripmnate, resembling the branches in minia- 
ture ; the first plumule always given off from the upper side of the rachis. 
Articulations of the stem and branches very variable in length, commonly 
from four to six times as long as broad; but sometimes very short, with 
