the description of that author in every particular: except that the compression attributed to the frond is certainly not a character of our specimen, and most probably originated in that of Gaudichaud from bad drying. Plate CLXXXTV. — Two states of R. Gaimardi, of the natural size. Fig. 1, ramuli and stichidia ; fig. 2, tetra-spores ; Jig. 3, section of stem : — magnified.
3. Khodojiela? comosa, Hook. fil. et Harv.; ramosissima, atro-rubescens, caule cylindraceo frondem percurrente ramis crebris alternis ornato, ramis cylindraceis elongatis planes alterne divisis erecto-patentibus sensini utrinque attenuatis, ramulis ultimis setaceis acutis abbreviatis vagis, capsulis ovatis breve pedicellatis. Nobis in Loncl. Journ. Bot. vol. iv. p. 263. Harv. Ner. Aust. t. xi. (Tab. CLXXXV.)
Var. /3. fibrillifera ; fronde tenuiori laxius ramosa, apicibus fibriiliferis.
Hab. Berkeley Sound, Falkland Islands ; both varieties abundant.
Caulis cylindraceus, 6-9 unc. longus, 1— 1-j lin. diametro (in var. gracilis) indivisus v. e basi in ramos primarios 3-4-divisus. Rami primarii secundariis perplui-imis aucti, secundarii ramulis brevibus setaceis ornati, ultimis in var. /3. fibriiliferis : omnes e tubulis septem circa axin centralem articidatam dispositis et strato exteruo cellulorum densorum circumdatis conflati. Ceramidia numerosa, secus ramulos idtimos tertiariosque disposita, parva, ovata, breviter pedicellata. Substantia fiaccida, opaca, primo visu iuarticulata, sed vere articulata. Color luride rufo-brunneus : — chart* arete adha?ret.
A very much branched species, variable in size and in the density of the ramification. In old specimens the stem becomes considerably incrassated and constricted at irregular intervals. Being unacquainted with the secondary fructification, we doubtfully refer this plant to Rkodomela : it may belong to Dasya.
Plate CLXXXV. — Two vars. of R. ? comosa, of the natural size. Fig. 1 a, branch and ramuli of var. a ; fig. 2 a s section of ditto ; fig. 3 a, tissue of ditto ; fig. 1 b, portion of branch and ramulus of var. /3. with ceramidia ; fig. 2 b, fibrilliferous apex of ditto : — highly magnified.
25. MELOBESIA, Lamx.
1. Melobesia verrucata, Larnx. Tolyp. JJexibles, p. 315. Decaisne in Ami. Sc. Nat. Ser. ii. vol. xviii. p. 126.
Var. Antarctica ; fronde circuniscriptione orbiculari lobata medio adnata margine integerrima libera superficie lsevi lineis concentricis uudulata, ceramidiis depresso-hemisphsericis : — an species distincta ?.
Hab. Var. /3. Herrnite Island, Cape Horn ; the Falkland Islands, and Kerguelen's Land; encrusting shells, and the sterns of Algae, particularly of Ballia Brunonis.
The M. verrucata is a native of the Atlantic Ocean and Mediterranean Sea ; the var. /3. of the Antarctic Ocean; of Lord Auckland's Group, New Zealand and Tasmania. The ceramidia are iutermediate in size between those of M. verrucata and M. pustulata, Lamx. We have little doubt of this being a new species ; but the materials for its determination are wanting.
26. DASYA, Ag.
1. Dasya pectinata, Hook. fil. et Harv.; setacea, rigida, purpurea, fronde basi nuda superne distiche decomposito-pinnata, ramis articulatis tri-striatis pectinato-pinnatis, ramulis (v. pinnulis) simplicibus alternis brevibus subulatis articulatis monosiphoniis, articulis diametro sesquilongioribus, ceramidiis urceolatis pedicellatis. Polysiphonia pectinata, nobis in Lond. Journ. Bot. v. iv. p. 267.
