Ser. RHODOSPERMEA. Fam. Ceramica. 
CALLITHAMNION CORYMBOSUM, 4%. 
Prats CCLXXII. 
Guy. 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 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 (favel/@), seated on the main 
branches, and containing numerous angular spores. CALLITHAMNION 
(Lyngb.),—from xaddos, beauty, and Oapnov, a Little shrub. 
CaLLITHAMNION corymbosum; frond setaceous at the base, capillary and 
byssoid above, flaccid, gelatinous, excessively branched ; secondary 
branches alternate, repeatedly dichotomous, subflabelliform, level- 
topped ; ramuli many times forked, with patent axils; apices obtuse; 
articulations of the branches from eight to ten times as long as 
broad ; tetraspores solitary, opposite the axils of the terminal forks, 
sessile, globose ; favellee binate, on truncated branches. 
CALLITHAMNION corymbosum, 4g. Sp. Alg. vol. ii. p.165. Harv. in Hook. 
Br. Fl. vol. ii. p.346. Harv. in Mack. Fl. Mid. part 3. p. 216. Harv. 
Man. p.112.. Wyatt, Alg. Danm. no. 92. 
CALLITHAMNION versicolor, 4g. Sp. Alg. vol.ii. p.170.  Harv.in Hook. Br. 
Fl, vol. ii. p. 346. Harv. im Mack. Fl. Hib. vol. ii. p.165. Harv. Man. 
p. 112. | 
PHLEBOTHAMNION corymbosum, Kiitz. Phyc. Un. p. 375. Sp. Alg. p. 657. 
PHLEBOTHAMNION versicolor, Kitz. Phyc. Un. p. 375. Sp. Alg. p. 657. 
CERAMIUM corymbosum, dy. Syn. p. xxvii. dg. Syst. p. 138. " 
CERAMIUM versicolor, 4g. Syst. p. 140. 
ConreRrva corymbosa, Hug. Bot. t. 2352 (articulations too short). 
Has. On the leaves of Zostera, the fronds of various Algee, and attached 
to rocks and stones, near low-water mark. Annual. Summer. Not 
uncommon, from Orkney to Cornwall. 
Geroar. Distr. Atlantic and Mediterranean coasts of Europe. Hast coast of 
North America. 
Descr. Root minute, giving rise to a dense tuft, composed of numerous fronds. 
Stem one to three inches long, the smaller specimens more slender than 
human hair, the larger as thick as hog’s bristles at base, soon attenuated 
and reduced to a byssoid fineness in the upper part of the plant, variable 
in ramification ; sometimes dichotomous from the very base, with no trace 
of a leading stem; sometimes (and more frequently) having a leading, 
subsimple stem set with closely placed, alternate branches. These branches, 
in full-grown plants, are excessively divided, having an ovate or fan-shaped 
K 2 
