- 146 — 



The var. filamentosa comes very near to Ulouema rhizophorura Fosl. ^), 

 but differs from it by the number of tlie oliromatophores, the former 

 having but one in each cell, whereas tlie latter must be considered to 

 have several chromatophores in each cell, as Foslie (1. c.) speaks of one 

 or more disc-shaped chromatophores in each cell and Sauvageau (1. c. p. 233) 

 says regarding the Ulonema rhizophornm : „La seule difference avec un 

 Myrionema, et mOme avec le M. vulgare, est la ramification eparse du thalle 

 rampant." I think that Ulonema rhizophornm Fosl. ought to be regarded 

 as a variety of Myrionema vulgare, analogous to the var. filamentosa of 

 M, Corunnas. The var. filamentosa is occasionally somewhat resembling 

 the Streblonema oligosporum Stromf., but differs from it by the presence 

 of assimilative filaments and the number of the chromatophores. 

 S. I eel. Eyrarbakki, Vestmannaeyjar. 



a b C d t yj 



Fig. 5. Myrionema globosum (Rke.) Fosl. f. fypira. (816:1.) 



Myrionema globosum (Rke.) Fosl. New or critical Norw. alga? p. 1 7. 

 Ascocyclus globosus Rke. Algenfl. p. 46, Atlas Tab. 17; Phycocelis globosus 

 Rosenv. Deux. Mem. p. 86, fig. 19 — 20. 



I have found this species growing on Rhodymenia palmata, Ghaeto- 

 moi'pha tortuosa, Cladophora rupestris and Acrosiphonia in the littoral 

 region. It has been collected with plurilocular sporangia in April, June, 

 July and September. 



The somewhat varying specimens 1 have referred to this species, 

 have all, as far as I can see in my alcohol material, one, or occasionally 

 two, chromatophores in each cell. The basal portion of the frond is a 

 disc, and the margin is either entire or it consists of free creeping fila- 

 ments, as pointed out by Rosenvinge (1. c), Svedelius (Ostersjons hafsalg. 



') M. Foslie: New or critical Norwegian Algse. Reprint from Det Kg), norske 

 Videnskabers Selskabs Skrifter, Trondhjem 1894, p. 19. 



