ALG OF TASMANIA. 441 
ramuli are either furnished with a series of distant, short, 
spinelike pinnules, or they are more or less dipinnate, the 
pinne in this latter case resembling the main ramuli in the 
former ; the ultimate pinnules always patent and spinelike. 
Articulations deeply furrowed, much shorter than broad, 
4 striate; the striae which mark the tubes as evident as those 
which divide the branch into joints, and thus the frond has 
a netted appearance.—Keramidia very small, sessile on the 
ramuli, ovate. The stem is seven-tubed as in the last two 
species. 
15. Polysiphonia acanthophora, Harv.; caule longissimo, 
crasso, indiviso, inarticulato, bi-tripinnato ; pinnulis elon- 
gatis, tenuibus, alternis, distantibus, ramulis minutis spinu- 
losis bi-tri-multifidis apice fibrilliferis distiche obsessis ; 
ramulis solum articulatis, articulis sesquilongioribus, bi- 
striatis. 
George Town, V. D. L., R. Gunn, Esq., n. 1291, 1297, 
1321.—Stem 8-10 inches long or probably more, cartila- 
ginous, from 4 to 1 a line or even more in diameter at base, 
gradually attenuated to the thickness of bristle above; pin- 
. hated with patent branches much more slender than itself, 
which gradually diminish in length from the lower part to the 
top, so that the general outline of the frond is ovate-lanceo- 
late. These branches are usually again once-pinnated, but 
in large specimens twice-pinnated, with slender patent pinne 
of from 4- an inch to 1i inches in length:—both stem, 
branches, pinnze and pinnule perfectly opake and inarticu- 
late. The pinnz and pinnule are distichously set with 
minute, jointed, spinelike ramuli, which are about $ a line in 
length or less, and either simple, bifid, trifid or multifid with 
alternate divisions, their apices producing colourless byssoid 
fibres. Fruit unknown. Stem internally with four principal 
tubes round a. minute central one, and a wide cellular fleshy 
Periphery. Colour in the dry state greyish brown, with a 
stain of red.— This is one of those inarticulate species which 
vili probably be separated from Polysiphonia, and perhaps 
Placed in Alsidium as at present defined. It bears an out- 
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