A very small plant, of which but few specimens were obtained, and by the dredge only : they are in a good state of fruit, and probably characteristic of the species.
Plate CLXXXIX. Fig. II. — 1, plant of the natural size ; 2, portion of ditto ; 3, ramuli ; 4, ditto, with favella ; 5, tetraspores : — magnified.
5. Callithamniox fiaccidum, Hook. til. et Harv. ; gracillimuni, fiaccidum, membranaceum, fronde laxe et vage decomposite ramosa, ramis prirnariis et secmidariis oppositis alternisve disticliis elongatis patentibus, ramulis ultimis brevibus simplicibus patentibus oppositis secimdisve apice incurvis, articulis ramorum prirnariorum diametro multoties secundariorum 6-10 -plo ramulorum sesquilongioribus pellucide roseis enerviis. Nobis in Lond. Joum. Bot. vol. iv. p. 273. (Tab. CLXXXVIII. Fig. I.)
Var. /3. alternifolium ; ramis ramulisque alternis secimdisve rarissime paucis oppositis.
Hab. Hermite Island, Cape Horn ; dredged up from about seven fathom water ; abundant.
Frons 2-4 una longa, laxe ramosa, membrauacea, flaccida. rosea. Caules ramique gracillimi, filiformes. A very beautiful and delicate species, remarkable for the ramification being often truly opposite, always so in var. a, two branches springing from opposite points of the same articulation. On the other hand, when, as in var. /3. they are alternate or secund, it is owing to the inner ramuli on the branches becoming abortive, those along the outer edge alone being developed. There is no other difference between the two varieties. Specifically the present is most closely allied to the C. Turneri, but it is much larger and more branching. The colour is a very bright rose, and from the delicacy of the filaments, the plant forms a beautiful object when properly displayed upon paper. The articuli of the stem are often singularly elongated.
Plate CLXXXVIII. Tig. T. — 1, plant of the natural size; 2, ramus and ramuli; 3, apex of ramulus; 4, favella : — magnified.
6. Callithauniox scoparium, Hook. fil. et Harv. ; aespitosum, caulibus fastigiatis, primario crasso inarticulato fibris intertextis fiexuosis stuposis vestito flabellatim ramoso, ramis prirnariis cauli similibus, secun-dariis strictis gracilibus pellucidis creberrime piimatis bipinnatisve quadrifariis e prirnariorum apicibus fasciculatim ortis fastigiatis, articulis diametro duplo triplo longioribus. Nobis in Lond. Joum. Bot. vol. iv. p. 173. (Tab. CLXXXIX. Fig. ILL)
Var. /3. ramidosum ; pinnis apice ramulis secundis ornatis.
Hab. Var. a . Berkeley Sound, Falkland Islands ; on rocks. Var. /3. Hermite Island, Cape Horn ; rare.
Frons 2-3 una longa, dense fastigiata. Caules robusti, narticulati, basi Integra, fibris stuposis dense vestiti, in discum latiusculum expausi. Rami cauli subsimiles, per totam longitudinem ramulis strictis dense fastigiatis quadrifariis vestiti (ut in Sphacelaria scoparia) ; secundarii articulati, vage ramosi, pinnati v. dichotomi secundive ; omnes erecti, ramulique plerumque appressi ; apicibus obtusis v. acutis simplicibus v. ramulis brevibus pectinatis ornati. Substantia rigida. Color luride purpureus.
A densely tufted species, with the habit of Sphacelaria scoparia, resembling amongst its congeners the C. tetricum of Britain, but abundantly different under the microscope. It has also been found in Tasmania.
Plate CLXXXIX. Fig. III. — 1, plant of the natural size ; 2, ramus and ramuli ; 3, apex of the latter ; 4, fibres at the base of the stem : — magnified.
7. Callithamnion Montagnei, Hook, fil.; fronde fruticosa ramosissima, caulibus prirnariis decomposes sensim alternatis crassis quadrifariis inarticulatis opacis, ramis inarticulatis striatis ramulis quadri-
