1. Cladothele Decaimei, Hook. fil. et Harv. ; in Lond. Jcncm. Bot. vol. iv. p. 293. (Tab. CXC.)
Hab. Berkeley Sound, Falkland Islands ; in the sea.
Radix fibrosa ? Frondes 4-6 una altse, caespitosae, filiformes, seta porcina crassiores, cylindraceae, flexuosae, plus minusve ramosae, ramificatione valde irregulari. Rami primarii elongati, saepe simplices, ramulis longis simplicibus saapissiine seoundis curvatis v. iucurvis vix attenuatis laxe donati. Substantia tenax. Color sordide viridis, siecitate cinerascens : — chartae laxe adhaeret.
A very curious plant, certainly related to Codium, especially to C. simpliciusculum, by the structure of the papillie that cover its surface, and from which we have derived the generic name. The axis is, however, of very different structure from that of Codium or of any other genus of Siphoneee, and more closely resembles that of Tolysiphonia. In the specific name we wish to pay a deserved compliment to our friend M. Decaisne, who has thrown much light on the affinities of the corallinoid Alga, especially those related to Siphoneee.
Plate CXC. — Tig. 1, plant of the natural size; 2 ramus and ramuli ; 3, longitudinal, and 4, vertical section of branch j 5, cellular tissue of ditto : — magnified.
42. BEYOPSIS, Lamx.
1. Bryopsis plamosa, Grev. Alg. Brit:). 187.
Var. 0. Arbuscula, J. Agardh, Alg. Medit. p. 21. B. Arbuscula, Ag. Sp. Alg. p. 451.
Hab. Hermite Island, Cape Horn, and the Falkland Islands ; abundant, both varieties.
The branches of the frond are narrower and pinnated nearer to the base, with the ramuli more uniform and shorter in some of the specimens than in others.
2. Bryopsis Rosa, Ag. Syst. Alg. p. 179. Bory in Buperrey Voy. Bot. p. 211. t. lA.fig. 1.
Hab. Hermite Island, Cape Horn, and the Falkland Islands.
None of our specimens equal those figured by Bory in size, though they coincide in all other respects with the descriptions published by that author and Agardh. Our opinion is, that the present plant is not distinct from the B.plmmosa, but is a large state of that very sportive species, depending probably on the temperature of the ocean it inhabits for its development. Some other species of this highly Protean genus are equally difficult to define; and we cannot but expect that a copious suite of specimens from different shores and depths will considerably diminish it.
43. VAUCHEEIA, DC.
1. Vaucheria Billwynii, Ag. ; Grev. Alg. Brit. p. 191. t. 19. Conferva frigida, Billwyn, t. 19.
Hab. Christmas Harbour, Kerguelen's Land ; on the ground amongst the Penguin Bookeries.
The patches are very extensive and rather more glaucous than others collected near Edinburgh, with which the Antarctic specimens appear otherivise entirely to agree. The capsules are not always globose, as figured by Mr. Hassall, (Brit. Fresh-water Algse) but often, if not more generally, horizontally elongated and gibbous ; as shown in Greville's ' Algae Brit.' (1. c.) where there is an excellent figure of this species.
2. Vaucheria easpitosa, Ag. ; Grev. Alg. Brit. p. 194.
Hab. Berkeley Sound, Falkland Islands ; on the moist borders of fresh-water lakes, and in pendent masses from dripping rocks.
These specimens are dried very badly, so that we have not much confidence in our identification of the species.
