MARINE ALG.'E OF Tllti SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 79 



thin-walled great interior cells (collapsing irrevocably when dry), we felt that we were 

 dealing with a new genus allied to Gracilaria, and we gave it the name of Leptosarca. 

 Subsequently we received from Dr Rudmose Brown a more complete plant, gathered in 

 the South Orkneys, which with a few other algae had been overlooked in the Scotia, until 

 that gallant ship was cleared out previous to being sold. This tine specimen bore ten 

 fronds, some of them sterile and having the structure of Leptosarca, and others tetra- 

 sporiferous with large cruciate tetraspores, thicker-walled internal cells, and a cortex 

 of short chains of cells arranged perpendicularly to the surface of the frond. Upon 

 finding these characters in the sporangiferous fronds, we thought it advisable to transfer 

 the species to Gracilaria, even though the conclusive evidence of the cystocarps is 

 still lacking. The finest examples of this species that we have seen were shown to us by 

 Dr Skottsberg, who collected them during the Swedish South Polar Expedition. 



In certain parts of the frond of G. simplex we noticed small filaments creeping 

 round the cell-walls. Reinsch (loc. cit., p. 413, tab. xv. figs. 11-13) records two species 

 of Entonema from South Georgia, endophytic in other algse ; but our plant does not 

 agree with these, nor indeed with any other species of the genus. We have only the 

 vegetative filaments of our endophyte, and we hesitate, therefore, to give any definite 

 opinion on it. Since, however, the algse from South Orkneys are few and interesting, 

 it is worth while recording it, as it may occur among other Antarctic collections. 



21. EPYMENIA, sp. Scotia Bay, South Orkneys, 9-10 fathoms, May 1903. 



Two specimens without fruit. They resemble E. obtusa in general habit and 

 structure, but they lack the midrib in the base of the flabellate branches. The length 

 of the midrib seems, however, to be a variable character in E. obtusa. 



22. PLOCAMIUM HOOKERI, Harv. Scotia Bay, South Orkneys, 9-10 fathoms, 

 August 29, 1903; April 1903; May 1903. 



The last specimen is so covered with diatoms as to be unrecognisable until it 

 is cleaned. 



Geographical Distribution. Kerguelen, Heard Island, South Georgia. 



23. P. COCCINEUM, Lynyb. Scotia Bay, South Orkneys, December 1903; 9-10 

 fathoms, May 1903. 



Geographical Distribution. Cosmopolitan. 



24. HYDROLAPATHUM STEPHANOCARPUM, A. and E. S. Gepp'm Journ. of Bot., xliii., 

 1905, p. 195, tab. 472, figs. 5-7. 



Frons fruticulosa 15-30 cm. alta irregulariter dichotoma 3-4 mm. lata valde costata 

 alata, ala pinnativenia ssepe destructa, prolificationes uumerosas lanceolato-lineares 

 costatas pinnativenias, venis oppositis couspicuis, monostromuticas usque ad 32 mm. 

 longas et 4 mm. latas, e costis emittens. Cystocarpia adparenter pedicellata, revera in 

 foliolis minutis transformatis e costa emergentibus sessilia, trichomatibus pluribus 

 instructa. (Figs. 12-14.) 



