5. MACROCYSTIS, Ag.
1. Microcystis pyrifera, Agardh, Sp. vol. i. p. 47. Nov. Act. Nat. Cur. vol. xix. p. 297. t. 26. f. 1.
Hab. Lord Auckland's group, Campbell's Island, and in the open sea to the south as far as the 65th degree.
The observations on this genus and its distribution, are reserved for the Cryptogamie portion of the other Antarctic Islands.
6. DESMARESTIA, Lamour.
] . Desmakestia viridis, Lamour.; fronde cartilaginea basi subcompressa, supra cylindracea decompositopinnata, piimis pinnulisque exacte oppositis nliformibus ultimis capillaribus. D. viridis, Lamo/ir. in Ann. Mus. xx. 25. Endl. Gen. PI. Suppl. vol. iii. p. 28. Kiitz. Phyc. Gen. p. 344. Dichloria viridis, Grev. Alg. Brit. p. 36. t. 6. Sporochnus viridis, Ag. Spec. Alg. vol. i. p. 154. Syst. p. 259. Eucus viridis, Ft. l)an. t. 886. Turn. Hist. Fug. t. 97. Engl. Bot. 1. 1 669.
Hab. Lord Auckland's group. {Br. Byall.)
We defer our remarks on this plant, and on the genus Desmarestia in general, to a future portion of this work. The present species was found abundantly at Christinas Harbour in Kerguelen's Land, Berkeley Sound, and Port William in the Falkland Islands, and at Cape Horn ; and will, therefore, come more properly along with some new species into the flora of those regions.
7. DICTYOSIPHON, Grev.
Obs. The following species differs in some points from this genus, being of a thicker substance and denser structure, and with the walls composed of a greater number of rows of cells, which are themselves very much smaller. The surface of the frond is, therefore, not in the least reticulated. Still the fructification is so identical with that of Dictyosiphon, that we are unwilling to separate it, especially since the habit is not dissimilar.
1. Dictyosiphon 1 fascicidatus, Hook. fil. et Harv.; caule filiformi subindiviso, ramis abbreviatis pluries ramosis quadrifariis raro oppositis ssepissime fasciculatis alternis vel secundis omnibus ramulisque basi attenuatis acutis, sporis densissime per ramulos sparsis serni-immersis. (Tab. LXIX. Fig. I.)
Hab. Lord Auckland's group ; on rocks in the sea.
Radix pusilla? Frondes circumscriptione lanceolatas, csespitosas, 4-8 unc. longse, fusco-olivacea;, membranacea;, vix coriaceae, cylindracese, v. subcompressse, primo filis articulatis laxe repletse, mox tubulosse et cavae, e cellulis minutis coloratis rotundis 3-4 serialibus interioribus majoribus formatae. Caulis indivisus vel basi in ramos elongatos simplices partitus, inferne setaceus, supra sensim latior, medio i-1 lin. latus, apicem versus attenuatus, per totam longitudinem ramis plurimis pateutibus vestitus. Rami breves, 1-2 unc. longi, nunc brevissimi, utrinque attenuate, irregulariter inserti, mine quadrifarii, nunc subdistichi, saepissimc fascicidati, alterni vel secundi, rarius oppositi ; ramulis conformibus setaceis, gracilibus, erectis, alternis, oppositis v. fasciculatis, simplicibus, basi attenuatis apice subulatis. AjcUI/p acutse. Sjiora olivacea; v. nigrae, ovales, per totam frondem sparsas, nee in soros aggre- gate, limbo tenui hyalino cinctee, semi-immersae, demum prominulae.
A single specimen of this plant, which seems to be common in Lord Auckland's group, was picked up by Dr. Lyall in Berkeley Sound, Falkland Islands. It was more bushy than the Auckland Island specimen, with longer branches ; the outline is ovate and not lanceolate ; the main branches chiefly are crowded and fasciculate, the minor ones of the ramuli more frequently distichous, often opposite and rather patent. In fact, part of the plant exhibits the bushy aspect of Dictyosiphon and part resembles Striaria ; the scattered fruit distinguishing it from the latter genus.
Plate LXIX. Fig. I. — 1, a specimen of the natural size ; 2, branch ; 3, section of ditto ; — magnified.
