10 ANTONY GEPP AND ETHEL §8. GEPP. 
crassee, inferne in stipitem plus minusve sensim augustatum, 1-3 cm. longum 
attenuate, stratis duobus contexte cellulis interioribus rotundato-angulatis magnis 
2-3 seriatis pachydermis (frondis sterilis majoribus maxime leptodermis collabentibus 
submonostromaticis) ; cellulis corticalibus filamenta ramosa verticalia efficientibus, 
tetrasporangia magna cruciatim divisa foventibus (frondis sterilis majoribus mono- 
stromaticis). 
Off Cape Wadsworth, Coulman Island. 
Geogr. Distr.—South Orkneys. 
This species is represented in the ‘ Discovery ’ collections by one specimen only, a 
single thin dried frond 22°5 em. long by about 1°5 em. broad at its widest part. 
Blunt and incomplete at apex, it tapers very gradually down to its attenuated stalk- 
like base. This frond is quite sterile, and owing to the collapsed condition of its cells 
as the result of drying, was not in itself sufticient for determination, for we altogether 
failed to make the ceils swell out again. Fortunately we found in the ‘Scotia’ 
collection from the South Orkney Islands two specimens, which clearly belong to the 
same species, and being preserved in spirit, and uncrushed, revealed to us the interior 
tissue in its natural condition. These ‘Scotia’ specimens were also sterile, and we 
described them under the name Leptosarea simplex (loc. cit.). Subsequently we 
received a more complete plant, also from the 8. Orkneys, which with a few other alge 
had been overlooked in the ‘Scotia, until she was cleared out previous to being sold. 
This plant bore ten fronds, some sterile, others tetrasporiferous. ‘The two kinds of 
frond exhibited differences of structure, the sterile being characterised by an internal 
layer of large, extremely thin-walled cells, bounded by a monostromatic cortex, as 
described for Leptosarea (loc. cit.), while the sporiferous fronds with their large cruciate 
tetraspores, thicker-walled internal cells and pluristromatic cortex compelled us to 
transfer this species to Gracilaria, of which genus it should perhaps form a new section. 
9, GRACILARIA DUMONTIOIDES. 
(Plates III. and IV., figs. 17-20.) 
Halosaccion dumontioides Hary. ex Dickie, Journ. Linn. Soc. LX. (1867), p. 239 (nomen tantum). 
Leptosarca dumontioides nob. in Journal of Botany, April, 1905, p. 108 (nomen tantum). 
Frons (vetusta incompleta) linearis, 6°5 longa, 4 mm. lata, complanata, membra- 
nacea, prolificationes plurimas, intervallis irregularibus cire. 4 mm. latis invicem 
separatas, Maxime e marginibus ambobus emittens ; prolificationes 4-15 em. longe 
infra medium valde attenuate tunc sensim sursum expansze vel anguste lineares 4mm. 
latze simplices vel cuneato-lineares latiores apicem versus dichotome, ramis valde 
divergentibus. Color rosaceo-ruber. Cystocarpia et tetrasporangia ignota. 
Northumberland Sound, 76° N. lat., July 1853, leg. D. Lyall (fig. 20); Cape 
Adare, 72° §. lat., February 24, 1904 (fig. 17). 
The only Antarctic specimen (fig. 17) which we have seen consists of a scrap of 
an old frond, destitute of base and apex, encrusted by a zoophyte, and bearing laterally 
