76 



The cells are of rather variable length, usually about as long as broad or 

 somewhat longer, up to 3 times as long, in the last case usually barrel-shaped. 

 On the other hand they may be sometimes much shorter than broad, up to 3 to 

 4 times as broad as long (fig. 15 B); they are then proportionally bi'oad, 9 — 12,5 n, 

 being otherwise 6,5 — 10/;? broad. The cells contain, as is well known, a star-shaped 

 chromatophore with a central pyrenoid. The colour is lilac; in very light localities, 

 however, it is faded, feebly yellowish or grayish. Such a pale yellowish specimen 

 was placed in a glass-vessel filled with sea-water in a room with subdued light for 

 some days. After 24 hours the colour was already somewhat reddish, and after 



cells partly very snort. — u nna Ji. the cells displaced, giving up tlie uni- 

 serial arrangement ; the cuticle in E very thick. — B and C from the Skage- 

 rak. the olliers from Sallingsuhd. — All figures 19():1. 



3 days the plant had a decided lilac colour. When dying the cells assume a light 

 blue-green colour. 



Concerning the reproduction I have made no observations. According to 

 ScHMiTZ (1894 p. 718 (14) and 1896 p. 314), monospores are produced by the or- 

 dinary cells, the cell-content being condensed and liberated as a naked spore. I 

 have not seen this spore-formation, but I have sometimes remarked, that single 

 cells were wanting in the filaments, probably because they had been set free in 

 the form of spores. 



The species has hitherto been found in the Skagerak, Limfjord and Kattegat, 



