angustatis, terminalibus attenuatis filiformibus acutis, margine nunc simplici iiunc processibus proliferis ’
subpinnatis onusto.—Harv. Alg. Exsic. n. 430.
Var. 0 . prolifera; segmentis majoribus e margine frondes piiinatas emittentibus. (Tab. CXCV. A )
Hab. Georgetown, Mrs. Fereday, JF. H. E ., etc.
Stipes au inch or more long, terete, subsolid, twice or thrice forked; each branch passing into the euneate base
of a flattened or compressed, much divided, dichotomous, flabelliform frond. The lower segments arc about -J inch
\ride, the upper about a line, and the terminal ones not a quarter of a line in breadth. Sometimes the branching is
perfectly regular and dichotomous. In other specimens the lower, and sometimes the upper segments, throw out
from their margin very numerous secondary fronds, which arc more or less regularly dichotomous. Thus the general
frond becomes densely and intricately branched. The colour is a deep rosy-red. The substance soft and lubricous,
an<l the plant closely adheres to paper in drying. It belongs to the section of the genus called Gymnophloea, and
raay range next to N. dichotoma.—P late CXCV. A. Fig. 1, a froud, the nat. size ; 2, section, magnified.
2. Nem a stom a ? d ensa (Harv.) ; fronde fuscescente teretiuscula dichotome v. vage ramosa, ramis
primariis crassis parum divisis, secuudariis filiformibus gracilibus quaquaversis creberrimis dichotome
multifidis ramos primarios omnino vestientibus, divisuris omnibus divaricato-patentibus axillisque rotundatis,
ramulis ultimis setaceis obtusis.—Earv. Alg. Exsic. n. 431.
Hab. Georgetown, on the mudflats, Gunn, JF. E . H.
Fronds G- 8 inches long, excessively dense and bushy. The main frond is upwards of a liue in diameter, and
sparingly branched in a dichotomous or irregular mamier ; its divisions very patent, and somewhat flexuous. This
frond throws out, throughout its whole length, and directed to every side, a vast number of slender, many times
dichotomous, filiform, divaricating branches, so that the general frand becomes excessively bushy. The lesser
branches are greatly more slender than their primaries, and their teminal laciniæ are not thicker than hog’s-
bristle. Every axil is very wide, and every ramulus squarroso-patent. The colour is a dull reddish-brown. The
substance soft and gelatinous. The filaments of the peripheiy are nearly free, and their ceUs cylindrical.— I am by
uo means assured of the genus to which this plant properly belongs ; and perhaps it would be better placed in
Nemaleon, or in the neighbourhood of that genus.
Gen. C III. KOREA, Harv.
(Harv. in Trans. R. I. Acad. vol. xxii.)
Frons carnoso-membranacea, plano-compressa v. subtcres, e stratis tribus cellularum composita;
stratum, medullare e cellulis maximis inanibus demum sæpe ruptis ; intermedium cellulis pluriseriatis
minoribus coloratis ; corticale filis moniliformibus verticalibus dichotomis muco cohibitis formatum.
FarelUe inlra pericarpium proprium apice spinis coronatum poro pertusum ad placentam basalcm affixæ,
filis arachiioideis laxe circumdatæ, sporas conglóbalas angulares foventcs. Tetraspores sparsæ, cruciatim
divisæ.
1. H o r e a sp e c io sa (Harv.); fronde lato-lineari applanata decomposite pinnata, ramis elongatis
ambitu lanceolatis sub-bipinnatis, pinnis pinnulisque oppositis patentibus, piunulis linearibus obtusis nunc
apice cirrhoso-hamatis, cystocarpiis sæpius marginalibus (paucis) apice spinoso-coronatis.—-//aj-î». Alg.
Exsic. n. 439.—(Tab. CXCIV. A.)
Hab. Mouth of the Tamar, rare, JF. E . U.
D istrib. Also found at Western Port, Victoria, JF. H. H.
Frond 12-16 inches long, and as much in the expansion of the branches ; three or four times pinnate, every
division being distichous. The principal branches are nearly half an inch in width, and so strongly compressed ,is
to be called flat ; the lesser branches are about a quarter of an inch wide, and the ramuli about a line. The ramification
18 pretty regularly pinnate, the pinnæ and pinnules being close together and nearly opposite, all patent, but
gently curving upwards. The colour is a pale red. The substance soft and gelatinous, soon decomposing in freshwater.
The cystocarps are few, scattered along the edges of the branches and ramuli.—P la t e CXCIV, A. Fig. 1, a
branch, the nat. size ; 2, section of the frond ; 3, a cystocarp :—the latter figures magnified.
2. H o r e a polycarpa (Harv.); fronde applanata basi cuneata decomposite dichotoma et vage
laciaiata, laciniis cuneato-liuearibus repetite furcatis sensim attenuatis plus minus papillosis apice subacutis,
cystocarpiis stellato-echinatis numerosissimis per totam frondem densissime sparsis.—Harv. Alg. Austr.
Exsic. «. 4 3 8 .— (Tab. CXCIV. B.)
H ab. East coast, Gnnn.
D istk ib. Shores of Victoria, JF. II. II.
Frond sessile, foliaceous, 6-8 inches long, euneate at base, divided in an irregularly dichotomous manner into
innumerable segments, which are from a quarter of an inch to nearly an inch broad, linear-euneate, repeatedly forked
or in-egularly laciniate, all the minor divisions suberect, the axils narrow, and rather acute. In specimens that bear
tetraspores, eveiy part of the frond is generally densely papillate, with linear processes half a line to a line or more
in length. In those that bear cystocaips, these generally take the place of the papillæ, the whole disc and margin
being thickly studded with them. The cystocasps are cromicd by four or five longish spines. The tetraspores are
abundantly scattered through all parts of the cortical layer in such specimens as produce them. Tbe colour is a
pale rosy-red, soon fading into greenish. The substance veiy soft and lubricous, soon decomposing in fresh-water.
In diying, the plant adheres firmly to paper.—P la t e CXCIV. B. Fig. 1, a plant with cystocarps; 2, a plant with
tetraspores, both of the »a/, swe,- S, fragment with four cystocaiqjs; 4, section of a cystocarp ; 5, tetraspores
the latter figures magnified.
T ribe X II. SPYRIDIACEÆ.
Gen. CIV. SPYRIDIA, Harv.
(Harv. in Hook. Br. Fl. ii. p. 336. Phyc. Brit. t. 46. J. Ag. Sp. Alg. ii. 338. Kütz. Sp, Alg. 665.)
1. S py r id ia filamentosa (Harv. Phyc. Brit. t. 4 6 ; J . Ag. Sp. AJg. ii. p. 340).—Ceramium fila-
mentosum, Ag. Conferva Grifii'thsiana, E. Bot. t. 2312.
H ab. Georgetown, common.
D istrib. Native of the warmer temperate parts of the Atlantic and Pacific Oceans, and in tropical
seas, reaching its most northern limit on the south coast of England.
The plant noticed in Hook. Lond. Journ. vol. iii. p. 449, as var. 0 verticillata, and on which Kützing has
founded his S. Tasmanica, belongs to Wrangelia, and will he found desa-ibed above, under the name W. setigera.
Spyridia? pellucida, Lond. Journ. 1. c., is CallUhamnion mucronatum, J. Ag.
T r ibe X I II. CERAMIACEÆ.
Gen. CV. CENTROCERAS, Kütz.
(Kütz. Linnæa, 1841, p. 741. Sp. Alg, p. 688. J, Ag. Sp. Alg. ii. 147.)
1. Centroceras clavulatnm (Mont. PI. Alg. p. 140; J . Ag. Sp. Alg. ii. p. 148; Harv, Ner.
Bor. Amer. part ii. p. 211. t. 83. f. C).—Ceramium clavulatum, Ag.
We have not seen Van Diemen’s Land specimens, but as this plant is veiy common on the opposite shores of
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