Ser. RHODOSPERME. Fam. Gelidiacee ? 
Puate CCXCIII. 
THAMNOCLONIUM HIRSUTUM, Xie. 
Grn. Cuar. Frond dendroid or flabelliform, compressed or plane, imper- 
fectly costate, rigidly horny or coriaceous, mostly covered with spi. 
nous tubercles, composed of two strata; the medullary stratum very 
dense, of slender, cylindrical, longitudinally seriated cellules ; cortical 
of roundish-angular, coloured cells. Fructification : 1, eystocarps ? ; 
2, cruciate ¢etraspores, contained in sporophylla.—THAMNOCLONIUM 
(Kiitz.), from Oapvos, a shrub, and Krwv, a branch. 
Frons dendroidea v. flabelliformis, compressa v. plana, immerse costata, rigide 
cornea et coriacea, se@pissime spinuloso-verrucosa, stratis duobus composita ; 
strato medullari densissimo, cellulis cylindraceis gracilibus longitudinaliter 
seriatis ; corticali cellulis rotundato-angulatis coloratis formato. Fruct.: 1, 
cystocarpia ignota; 2, tetraspore cruciatim divise, in sporophyllis propris 
evolute. 
THamNoctonium Airsutum ; frond decompound-dichotomous, fastigiate ; 
branches terete, or the smaller ones subcompressed, closely covered 
with muricated warts, obtuse ; spore-leaves in rose-like tufts, lateral 
or terminal, containing beneath their surface cruciate tetraspores. 
T. hirsutum ; fronde decomposito-dichotoma fastigiata, ramis teretibus v. mino- 
ribus vix subcompressis creberrime echinato-verrucosis obtusis ; sporophyllis 
rosulatis lateralibus v. terminalibus in strato corticali tetrasporas cruciatas 
Jfoventibus. 
THAMNOCLONIUM hirsutum, Kitz. Phyc. Gen. p. 392; Sp. Alg. p. 193. 
Harv. in Hook. Fl. Tasm. v. 2. p. 295. 
Potypuacum dichotomum, J. 4g. Linn. v. 15. p. 3. 
Fucus hirsutus, Herd. Berol. 
Has. South coast of New Holland. Tasmania. 
Grocer. Distr. Said to be found also at Port Natal, A7zitz. 
Descr. Roof a broad rigid disc, an inch or more in diameter. Fonds several 
from the same disc, 6-10 inches high, simple (or stipitate) for 2-8 inches 
above the base, then forking, and afterwards many times forked or alter- 
nately branched. The dranches are nearly level-tipped, erect, or erecto- 
patent, with acute axils; the larger ones are quite terete, the upper slightly 
wider and somewhat compressed. All parts, save the denuded stems and 
bases of old branches, are closely covered with oval or oblong multifid-foliated 
or echinate warts, peltate in insertion, fixed to the branch by a slender neck. 
A section of a young branch (Fig. 3) shows four of these, surrounding a 
scarcely developed axis. In old sections the axial portion is more enlarged 
