MARINE ALGA. 
at aOPAYCH A, AND FLORIDEA,. 
By Antony Gepp, M.A., F.L.S., and Eruet 8. Grpp. 
(Four Plates.) 
TuHoucH the number of species, apart from the Corallinacee, collected within the 
Antarctic Circle by the British Antarctic Expedition is but small, and the specimens 
themselves are mostly fragmentary and badly preserved, yet among them are included 
some interesting novelties. Some of these were briefly described in the Journal of 
Botany, April, 1905, pp. 105-109, with the ale of the Scottish National Antarctic 
Expedition. One of them, which is common to both collections, Gracilaria simplex 
(Leptosarca simplex), is unfortunately only represented in the present collection by 
dried and crushed material; and though it is markedly distinguished by its 
vegetative structure, the details of this could not be worked out until the clue was 
given us by some pickled material in the ‘Scotia’ collection. A second species of 
Gracilaria, G. dumontioides, comes from Cape Adare, and is extremely interesting 
from the point of view of distribution, for it appears to be the same as an Arctic 
species which was collected in 1853 by Dr. David Lyall in the very northerly latitude 
of Northumberland Sound, and was named Halosaccion dumontioides by Harvey, but 
never described ; for he had dried sterile material only, in which, through the collapse 
of the inner cells, the structure is obscured. 
Magnificent specimens of Lessonia grandifolia were brought back by the 
‘Discovery, the largest lamina attaining a length of 24 feet before it was dried. 
Infant plants of the same species (about one inch long) were found attached to 
Desmarestia harveyana. We erroneously recorded (Journal of Botany, loc. cit.) 
L. grandifolia as having been collected in the South Orkneys by the Scottish 
Expedition. Though we found the two plants so much alike in external habit, we 
have been compelled, after a further examination of their minute structure, to separate 
them specifically. The ‘ Scotia’ plant will be found below, described under the name 
L. simulans. The oceurrence of two such large new species of alge is a rather 
startling indication of how much may yet remain to be investigated in the South Polar 
marine flora. 
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VOL. III. ZL 
