— 146 — 



The var. filamentosa comes very near to Ulonema rhizophorum Fosl. *), 

 but differs from it by the number of the chromatophores, the former 

 having but one in each cell, whereas the 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 différence avec un 

 Myrionema, et même avec le M. vulgare, est la ramification éparse du thalle 

 rampant." I thiuk that Ulonema rhizophorum Fosl. ought to be regarded 

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

 M. Gorunnæ. The var. filamentosa is occasionally somewhat resembling 

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

 of assimilative filaments and the number of the chromatophores. 

 S. I c el. Eyrarbakki, Vestmannaeyjar. 



Fig. 5. Myrionema globosum (Rke.) Fosl. f. typica. (316:1.) 



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

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

 Rosenv. Deux. Mém. p. 86, fig. 19-20. 



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

 morpha tortuosa, Gladophora rupestris and Acrosiphonia in the littoral 

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

 July and September. 



The somewhat varying specimens I 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 (Östersjöns hafsalg. 



*) M. Foslie: New or critical Norwegian Algæ. Reprint from Det Kg], norske 

 Videnskabers Selskabs Skrifter, Trondhjem 1894, p. 19. 



