n iu e . c c L i n x .
Ser. E hodospermeæ.
•WH-H.del ctuai.
Fam. Ceramieoe.
P l a t e CCLXXIX.
CALLITHAMNION HOOKLRI, A g .
G e n . Ch a r . 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 hyaüne.
F ru it of two kinds, on distinct p lants: 1, external tetraspores, scattered
along the ultimate branchlets, or borne on little pedicels; 2,
roundish or lobed, berry-like receptacles (favella) seated on the main
branches, and containing numerous angular spores. Ca llithamnion
(L y n g h ), from /caXXos, beauty, and bapnov, a little shrub.
Callithamnion Hooheri; stem setaceous, inarticulate or nearly opake,
with traces of joints, simple, set with one. or more series of alternate,
spreading, flexuous branches, the smaller of which are articulated,
and all densely plumulate ; plumules patent, naked below, pinnate or
subbipinnate above ; the pinnæ or pinnules subhorizontal or divaricate,
the lowest longest; articulations twice or thrice as long as
broad; tetraspores numerous, sessile on the pinnules; favellæ terminal,
binate.
Callithamnion Hookeri, Ag. Sp. Alg. vol. ii. p. 179. Harv. in Hook. Br.
Bl. vol. ii. p. 341. Harv. Man. ed. 1. p. 106,
Callithamnion lanosum, Harv. in Hook. Br. FI. vol. ii. p. 341. Wyatt,
Alg. Ban. no. 139.
Callithamnion spinosum, Harv. in Hook. Br. FI. vol. ii. p. 345. Harv.
Man. ed. 1. p. 111.
P hlebothamnion Hookeri, Kütz. Phyc. p. 375. Sp. Alg. p. 653.
P hlebothamnion spinosum, Kütz. Sp. Alg. p. 653.
Ceramium Hookeri, Ag. Syn. p. xxvii. Hook. FI. Scot. p a rt 2. p. 85. Ag.
Syst. p. 138.
Conferva Hookeri, Billw. Conf. 1 .106.
H a b . On various Algæ between tide-marks, also on rocks near low watermark,
and at a greater depth. Annual. Summer. Dispersed along
the British shores, from Orkney to Cornwall, and in Ireland; not
uncommon.
Geogr. Dis t r . Atlantic shores of Europe.- but rare.
D e scr. Boot a minute disc. Fronds densely tufted, one to four inches in length,
and as much in expansion, having a conical or pyramidal outline, the lower
branches being longest, the rest gradually shorter upwards, not perfectly
distichous, and sometimes densely bushy, with branches turned in every
direction. Stem mostly undivided, as thick as a hog’s bristle, opake and full
of veins, or (in young specimens) obscurely marked with joints, closely set
throughout with lateral, very patent branches, similar to the main stem.
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