Alge, by W. H. Harvey.) FLORA OF TASMANIA. 329 
to be called flat ; the Jesser branches are about a quarter of an inch wide, and the ramuli about a line. The ramifi- 
cation is pretty regularly pinnate, the pinne 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 fresh- 
water. The cystocarps are few, scattered along the edges of the branches and ramuli.—PLark CXCIV. A. Fig. 1, a 
branch, the xat. size; 2, section of the frond; 3, a cystocarp :—the latter figures magnified. 
2. Horea polycarpa (Harv.); fronde applanata basi cuneata decomposite dichotoma et vage 
laciniata, laciniis cuneato-linearibus repetite furcatis sensim attenuatis plús minus papillosis apice subacutis, 
cystocarpiis stellato-echinatis numerosissimis per totam frondem densissime sparsis.—Harv. Alg. Austr. 
Exsic. n. 488.—(Tap. CXCIV. B.) 
Has. East coast, Gunn. 
Distris. Shores of Victoria, W. H. DH 
Frond sessile, foliaceous, 6-8 inches long, cuneate 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-cuneate, repeatedly forked 
or irregularly laciniate, all the minor divisions suberect, the axils narrow, and rather acute. In specimens that bear 
tetraspores, every 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 cystocarps, these generally take the place of the papille, the whole disc and margin 
being thickly studded with them. The cystocarps are crowned by four or five longish spines. The /eíraspores are 
abundantly scattered through all parts of the cortical layer in such specimens as produce them. The colour is a 
pale rosy-red, soon fading into greenish. The substance very soft and lubricous, soon decomposing in fresh-water. 
In drying, the plant adheres firmly to paper.—PrATE CXCIV. B. Fig. 1, a plant with cystocarps; 2, a plant with 
tetraspores, both of the nat. size; 3, fragment with four cystocarps; 4, section of a cystocarp; 5, tetraspores :— 
the latter figures magnified. 
Tre XII. SPYRIDIACEZ. 
Gen. CIV. SPYRIDIA, Harv. 
(Harv. in Hook. Br. Fl. ii. p. 336. Phye. Brit. t. 46. J. Ag. Sp. Alg. ii. 338. Kütz. Sp. Alg. 665.) 
l. Spyridia filamentosa (Harv. Phyc. Brit. t. 46; J. Ag. Sp. Alg. ii. p. 340).—Ceramium fila- 
mentosum, Ag. Conferva Griffithsiana, E. Bot. t. 2312. 
Has. Georgetown, common. 
Disteıs. 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. ß verticillata, and on which Kiitzing has 
founded his S. Tasmanica, belongs to Wrangelia, and will be found described above, under the name JF. setigera. 
Spyridia? pellucida, Lond. Journ. l. c., is Callithamnion mucronatum, J. Ag. 
Tre XIII. CERAMIACEE. 
Gen. CV. CENTROCERAS, Katz, 
(Kiitz. Linnea, 1841, p. 741. Sp. Alg. p. 688. J. Ag. Sp. Alg. ii. 147.) 
1. Centroceras clavulatum (Mont. Fl. Alg. p. 140; J. Ag. Sp. Alg. ii. p. 148; Harv. Ner. 
Bor. Amer. part ii. p. 211. t. 33. f. C).—Ceramium clavulatum, 4g. 
We have not seen Van Diemen's Land specimens, but as this plant is very common on the opposite shores of 
VOL. II. 4er 
