Fig. 



13. 



y> 



14. 



» 



15. 



» 



16. 



ö 



17. 



» 



18. 



» 



19. 



KONGL. SV. VET. AKADEMIP^NS HANDLINGAR. BAND. 20. N:0 5. 3.35 



Vertical, tangential thin section. ^%. 



Part of the basal system of the fvond in thin radial section. ^""/j- 



Part of the thiokening system of the frond. *"%. 



Part of horizontal, tangeutial, superficial thin section. *"%. 



Section of a part of the frond provided with a conceptacle of sporangia. '"%• 



Part of the roof of a conceptacle of sporangia, delivered from lime. *""/i. 



Sporangium. ^''"/j. 



PLATE 6. 

 Lithotliamniori flavescens. Fki. 1—7. 



Fig. 1. Part of frond covering Lithothamion compactum. Vj. 



» 2. Conceptacle of sporangia, seeu from above. *''/j. 



« 3. Thin radial section with a grown-in conceptacle of sporangia. Of the sporangia only the gelinated 



tips remain. *"/,. 



» 4. Thin radical section of the lower part of the frond. ^""/i- 



'> 5. Part of horizontal, tangentical, snperficial thin section. ^""/i. 



» 6. Part of the roof of a conceptacle of sporangia, d(divercd from lime. ""'"/'i. 



Lithotliamnion compactum. Fig. 8—1.2. 



Fig. 8. Part of a crnst-complex with a young crust on its snrface. Vi- 



» .9. Thin vertical section of an older crust-oomplex. ''%. 



» 10. Part of the basal system of the frond in thin radial section. *"%. 



" 11. Part of the thickening system of the frond. *"*'/i- 



» 12. Part of snperficial, horizontal, tangential thin section. *""/r 



PLATE 7. 

 Rbodomela virgata. 



Fig. 1. Pirst year's plant in summer habit. Yj. 



» 2. First year's plant in autumnal habit. Vi- 



» 3. Part of a braneh with stånds of sporocarps developed during the winter. Vi- 



» 4. Stånd of sporocarps. *%. 



» 5. Stånd of antheridia. *%. 



» 6. Stånd of tetrasporangia. *"/'. 



» 7. Part of cross section of the main axis of an older plant near the base. ^^/j. 



" 8. Part of median longitudinal section of the main axis of an older plant near the base. **%. 



PLATE 8. 

 Rhodomela subfusca. 



Fig. 1. First year's plant in summer- and autumn-habit. '/,. 

 » 2. First year's plant in winter habit. Vi- 



