Page:The Botany of the Antarctic Voyage.djvu/522

486 I question whether I. micans be more than a membranous fonn of /. Radula : the former always preferring the quieter harbours, where its fronds are sometimes as thin as those of a Deksseria, quite unfitted to withstand the rough seas of the outer coasts, which wash the almost uninjured fronds of the /. Radula ashore in broad sheets, as large and as red as an ordinary pocket-handkerchief.

Though sometimes almost equally thin, the substance of the /. micam is never so membranous as that of a Deksseria. The colour, though not so bright a rose, or so delicate when the plant is dried, is, when seen in the living state, much more varied and more beautiful. The texture is such that the slightest motion of the water causes the frond to undulate throughout from the base upwards without falling into folds : each portion of the surface, when presented at a certain angle to the eye, reflecting back the most brilliant metallic tints of azure, steel-blue, pink, and purple. A more beautiful object in the water is not to be found in the whole order of Alqce than this, when seen from a boat in calm weather and sunshine ; though it is seldom that such opportunities occur in the latitudes it inhabits. I have not been able to detect any strise on the surface of the frond, which is formed of cells so densely packed that they coalesce into a homogeneous cartilaginous tissue.

We have no hesitation in pronouncing this as identical specifically with the I. cordata of the Banks of Newfoundland and the Cape of Good Hope ; of which species there is an excellent figure in the 'Historia Fucorum', coinciding with that of Bory in Duperrey's Voyage. The descriptions, both of Agardh and Turner, particularly mention the iridescence of their specimens. The only differential characters noted by Bory, who justly indicates the close affinity of /. micans with /. cordata, are the slight discrepancy in the bluntness of the apices of the fronds and depth of the lobes at the cordate base. We are, however, well assured that snch characters are all too slight; for we could not, either at the Cape of Good Hope or the Falkland Islands, distinguish between the fonns of this Iridaa with a cordate and those with a cuneate base to the frond. We are, however, far from asserting that there may not be from the two last-named localities two species here confounded (one of which, the /. micans of Boiy, is the same with the F. cordatus of Turner), though we strongly incline to the opposite opinion.

31. PHYLLOPHORA, Grev.

1. Phyllophora cuneifolia, Hook. fil. et Harv.; fronde stipitata basi ramosa lato-cuneata prolifera integra emarginata v. biloba e margine disco v. apice frondes consimiles emittente.

Hab. Port William and St. Salvador Bay, Falkland Islands ; Christinas Harbour, Kerguelen's Land; rare.

Frondes omnes stipitata?. Stipes compressus interdum subplanus, ima basi plerumque angustissima, sensim in laminam latam cuneatam deltoideamve dilatatus, basi divaricatim ramosus, bis, ter pluriesve divisus. Frondes primaria? 1-2 unc. longae, 1-1 -j latas ; apice latiore late rotundato, emarginato, retuso v. bilobo ; segmentis rotundatis, rarius erosis ; secundaria; primariis omnino similes sed colore pallidiores et basi simplices, saepe frondes tertiarias emittentes, bine planta vetusta catenatim ramosa evadit. Fructus ? Substantia tenuiter cartilaginea, subcornea, basi opaca. Color ut P. Brod'uei. — Chartae vix adhaeret.

Certainly distinct from P. obtusa, the only one of the genus hitherto described as a native of the southern temperate hemisphere, but perhaps not equally so from P. Brodiai. Still our specimens are very different from the ordinary British form of that plant, in the much shorter stipes, and larger broader frond, which is much less lobed and the lobes are not so narrow or elongated, or separated by so deep a sinus.

2. Phyllophora obtusa, Grev. Fl. Antarct. Pt. 1. p. 187.

Hab. Hermite Island, Cape Horn ; dredged up from five fathom water, very rare.

The specimens of this species are sufficiently characteristic, though few in number. It is also a native of the Cape of Good Hope and Lord Auckland's Group.