ALGÆ OF TASMANIA. 439 
fascicles of ramuli. To the naked eye it is not very unlike 
some states of Ceramium obsoletum.—A. transverse section of 
the stem shows a large central tube, surrounded by eight 
or nine others of moderate size, and these externally defended 
by a wide periphery composed of slender broken cellules 
containing endochrome, which cause the opake appearance 
of the stem. In P. Gunniana the structure is very similar, 
except that the periphery is very much narrower, and the 
tubes proportionally larger. 
12. Polysiphonia frutex, Harv.; frondibus aggregatis, fruti- 
culosis, ramosissimis, articulatis, sulcatis; caulibus basi 
ultrasetaceis, sensim attenuatis, et in ramis divaricato- 
patentibus, decompositis, alternis solutis ; ramis secun- 
dariis bipinnatis, pinnis distantibus, patentibus; pinnulis 
brevibus, simplicibus v. ramulosis, apice fibris hyalinis, 
byssoideis ornatis ; articulis omnibus brevissimis, diametro 
equalibus v. brevioribus, 4 striatis, keramidiis . . . . ? 
George Town, V. D. L., R. Gunn, Esg., n. 1317, and one 
of the specimens marked 1316.—Fronds 2-4 inches high, 
forming globose bushy tufts, branching in every direction 
from the immediate base, the branches equalling the stem in 
length, or no distinct stem visible;—all excessively branched, 
the lesser branches alternate, very patent or divaricate, 
Setaceous below, attenuated upwards, straight, bi-tripinnate, 
with distant alternate pinne; these in their turn having 
distant, short, spinelike pinnule, which are sometimes again 
 pinnellate ;—all the apices terminating in colourless byssoid 
fibres. Colour dull grey or brownish, staining the paper 
reddish. Articulations visible from the base to the apex, 
very short. A transverse section of the stem shows a small 
central siphon surrounded by seven large tubes, without any 
external cellular periphery ; the stem is consequently fur- 
Towed.—This has a good deal the habit of the European 
P. fruticulosa (whence the specific name), and several of the 
Characters of P. subulifera ;—but it is distinct from both. 
13. Polysiphonia fuscescens, Harv.; frondibus aggregatis, 
ticosis, ramosissimis, articulatis, sulcatis, setaceis ; e basi 
