276 



F. B0RGESEN 



Fig. 21. Galaxaura spec, part of specimen, c. l-s/l- 



plant is strongly incrusted with lime. The thallus is terete and the surface is in 



parts nearly glabrous, but mostly covered by short stiff reddish assimilating 



filaments scattered evenly and densely over the surface, no annulation being visible. 



The colour of the dried plant is when denudate a greyish-green while the 



parts covered with assimilating fila- 

 ments have a sordid red-brown tinge. 

 In the spirit material the whole thallus 

 is, as said above, terete while in the 

 dried material the youngest parts col- 

 lapse. 



The transverse section shows that 

 the medullary tissue consists of thick- 

 walled filaments more or less subdicho- 

 tomously branched and woven together. 

 Their diameter varies round 12 jj., but 

 thinner and thicker ones are present. 

 Innermost the peripheric tissue 

 (Fig. 22) is composed of large roundish 

 or irregularly lobed cells, carrying quite 

 short, often dichotomously branched 

 filaments of 2 — 3 cells. The lower cells 

 of these branches are larger and about 



Fig. 22. Galaxaura spec, (same as in fig. 21). 

 Cross section of thallus showing short assimilat- 

 ing filaments, c. 200 /i. 



