14 M. FOSLIE, (Schwed. Südpolar-E\p. 



Area: South Georgia: Cumberland Bay, May Harbour, f. typica (Skottsbkrg); 

 South Orkneys: Scotia Bay f. typica ("Scotia"); the Wandel Island in the Gerlache 

 Channel, west of the northern part of Graham Land, f. ivandelica (TuRQUET); 

 Louis Philip Land: Cape Roquemaurel. f. typica (Skottsberg). ' 



4. Lithophyllum falklandicum Fosl. 



Alg. Not. II (1900), p. 24; Lithophyllum Marlothii f. falklaiidica Fosl. Vidensk. Selsk. 

 Aarsber. (Bot. Saml.) for 1904 (1905); tab. nostr. 2, fig. 10 — 13. • 



Thallus at first crustlike, then developing wartlike excrescences, or very short, 

 knobby branches, simple or irregularly divided, about i mm. thick, finally densely 

 crowded, partly anastomosing, with thickened ends, cap-like coverings, or feebly 

 plicate. Conceptacles (of sporangia?) convex or subconical, 120 — 200 \.i in diameter. 



At first I held this alga as representing a form of Lithopli. Marlothii from 

 South-Africa, and it may be questionable whether this is not actually the case. I 

 have, however, decided on considering it as an independent species, as the ex- 

 crescences are frequently a little thinner than in the African species, the structure 

 on the other hand often a little coarser. We cannot, however, attach too much 

 weight to these characters till a larger material of both species than the present 

 one is in hand. 



The alga covers mussels or stones. As a general rule, it establishes several 

 crusts on the same substratum, and when these crusts, in grow ing on. come in con- 

 tact, the crenules meeting are curved upwards and against each other, or one is 

 growing caplike over the other. At the same time are developed independent ex- 

 crescences or very short, knobby branches which are often irregularh' divided. These 

 excrescences or short branches finally become densely crowded, partly anastomos- 

 ing, forming masses on the substratum up to about i cm. thick, though frequently 

 thinner. 



In a section I have seen only a few hypothallic cells. They were 11—22 a 

 long and 7 — 11 ii broad, but a hypothallium well developed will probably show 

 somewhat different proportions. The cells of the perithallium are 9 — 14 or up to 

 20 ,(( long and 7 — 9 11 broad. In a single young crust probably belonging to the 

 same species the cells were partly horizontally elongated, about 7 by 9 u. 



Conceptacles not dissolved occur very scarcely, and sporangia hav'e not yet 

 been found. Scars from dissolved ones are 150—250 u in diameter. 



Lithoph. falklandicujii is litoral and sublitoral. descending to a depth of about 

 4 fathoms. It seems to occur in small numbers. Specimens collected in the 



' From this loclaity only a fragmentary crust, growing on stone, somewhat tlispersed, has been brought 

 home. But according to the label the species was commonly growing. 



