Plate LXXVII. Fig. 1, favella in situ ; 2, the same removed with the involucre laid open ; 3, sphserospores : — magnified.
82. CERAMIUM, Adams.
1. Ceramium rabrum, var. y, secundatum, Agardh, Sp. AJg. p. 149. Cer. secundatum, Lgngb. Ilydr. Ban. t. 37.
Var. f, tenue, Agardh, Sp. Alg. vol. ii. p. 119.
Hab. Lord Auckland's group and Campbell's Island ; both varieties abundant.
2. Cerajiiuji diaphanum, Agardh, Sp. Alg. vol. ii. p. 150. Var. /3, AucMcmdiewm, proliferum, articuhs brevibus.
Hab. Lord Auckland's group; not common.
Apparently a curious state of the C. diaphanum.
3. Ceramium cancellatum, Agardh, Sp. Alg. vol. ii. p. 145.
Hab. Lord Auckland's group ; parasitic on other seaweeds, rare. Our specimen entirely agrees with others collected at the Cape of Good Hope, and with the description of Agardh ; it is doubtful, however, whether all may not be varieties of C. obsolelum, Ag., from which they differ mainly in the more branched and less virgate habit. One of our South African specimens is so repeatedly branched, as eminently to justify Agardh' s character, "ramis distichis multifidis quasi cancellatis ;" that from Lord Auckland's group is taller and the extreme divisions alone retain that character; neither of these are more than four inches long; we have, however, much larger examples, in which it is wholly lost. The station of Agardh's C. cancellatum is dubious, and his comparison of it with a plant brought from the Cape of Good Hope by Gaudichaud, renders it very probable that the Southern Ocean is its place of growth.
33. GEIFFITHSIA, Agardh.
1. Griffithsia setacea, Ag.? vol. ii. p. 129.
Hab. Lord Auckland's group.
Our young aud mutilated specimens of what we refer to G. setacea are not sufficient for a satisfactory determination of the species. The articulations are rather narrower than in the European plant, but they do not otherwise differ.
34. CALITHAMNION, Lyngb.
1. Calithamnion gracile, Hook. fil. et Harv.; filo prirnario repente rarnoso, caulibus erectis laxe bi-tripinnatis, pinnis remotis valde «longatis, pinnulis brevibus alternis erecto-patentibus simplicibus v. apice ramulosis, articuhs primariis diametro 4-5-plo, secundariis sub 3-plo longioribus.
Hab. Campbell's Island ; dredged up in four fathoms water.
Fila 1-2 unc. longa, gracillima, e fibrillis repentibus ramosis orta, laxe irregulariter alterne rarius opposite pinnatim divisa. Spharospora sessiles, rninutas, sphasrica?. Favella ignotae. Articuli pellucicb. Color roseus. Substantia tenera.
2. Calithamnion pectin atum, Mont.; "microscopicum, filo prirnario repente pinnis pinnulisque oppo-
