56 
Algce of Tasmania. 
auce.—Keramidia very small, sessile on the ramuli, ovate. Tli e 
stem is seven-tubed as in the last two species. 
15. Polysiphonia acanthophora, Ilarv.; caule longissimo, crasso, 
indiviso, inarticulato, bi-tripinnato ; pinnulis elongatis, tenui- 
bus, alternis, distantibus, ramulis minutis spinulosis bi-tri- 
multifidis apice fibrilliferis distiche obsessis; ramulis solum 
articulatis, articulis sesquilongioribus, bistriatis. 
George Town, V. D. L., R. Gunn, Esq., n. 1291, 1297, 1321. 
—Stem 8-10 inches long or probably more, cartilaginous, from 
4 to J a line or even more in diameter at base, gradually atte¬ 
nuated to the thickness of bristle above; pinnated with patent 
branches much more slender than itself, which gradually diminish 
in length from the lower part to the top, so that the general out¬ 
line of the frond is ovate-lanceolate. These branches are usually 
again once-pinnated, but in large specimens twice-pinnated, with 
slender patent pinme of from J an inch to 1£ inches in length; 
both stem, branches, pinnee, and pinnulee perfectly opaque and 
inarticulate. The pinna; and pinnuke are distichously set with 
minute, jointed, spinelike ramuli, which are about a line i n 
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 ot red.—This is one 
of thase inarticulate species which will probably be separated from 
Polysiphonia, and perhaps placed in Alsidium as at present 
defined. It bears an outward resemblance to P. byssoides, but 
is of a totally different structure; and it also something resembles 
Acanthophora Delilii, whence the specific name. 
Tribe 2. Chonduie.*, J. Ag. 
16. Bonnemaisonia elegans, Ag.; froude compressa, membrana- 
cell, anguste lineari, decomposito-ramosissima; ramis alternis, 
flabellatis, ramulis setaceo-subulatis distichis alternis utrinque 
pectinatis; keramidiis solitariis ovatis in jugamento immersis, 
poro ad axillam directo. Ag. Sp. Alg. vol. i. p. 198. 
