KONGL. SV. VET. AKADEMIENS HANDL. BAND. 20. N:0 5. 341 



Fig. 9. Part of the same transverse section with three lacunse muciferse (1.). '""/i. 

 " 10. Part of a transverse section of the lamina with a lacuna mucifera. '"%■ 



Alaria dolichorhachis. Fig. 11—18. 



Fig. 11. Part of a transverse section of the stipe. ^^/,. 



» 12. Transverse section of the stipe near the base in an older specimen. Vi' 



» 13. Transverse section of the older part of the rhachis, not bearing sporophylls, of the same specimen. '/,. 



» 14. Transverse section of the part of the rhachis bearing- sporophylls, of the same specimen. Vi- 



» 15. Transverse section of the rhachis where it passes into the costa. '/i- 



» 16. Transverse section of the costa at the middle of the lamina, '/j. 



» 17. Zoosporangium. *""/]. 



» 18. Paraphysis. """/i- 



Alaria esculenta f. typica. Fig. 19. 



Fig. 19. Transverse section of the costa at the middle of the lamina. Specimen from the west coast of 

 Norway. Vi' 



Alaria membranacea. Fig. 20. 



Fig. 20. Transverse section of the costa at the middle of the lamina, in a specimen from the coast of Nor- 

 wegian Finmarken. */j. 



Alaria oblonga. Fig. 21—24. 



Fig. 21. Transverse section of the stipe and 



» 22. Transverse section of the part of the rhachis bearing sporophylls, of the same specimen. %. 



« 23. Transverse section of the costa of a young and 



» 24. of an older specimen. Vi- 



Alaria elliptica. Fig. 25—26. 



Fig. 25. Transverse section of the costa of a young and 

 » 26. of an older specimen. Vi- ' 



PLATE 26. 

 Scytosiphon attenuatus. Fig. 1—5. 



Fig. 1. Several specimens issuing from the same fastening-surface. Vi- 



» 2. Detached specimen, '/j. 



» 3. Transverse section of the wall of the frond with gametangia (zoosporangia multilocularia). *""/i. 



» 4. Longitudinal section of the wall of the frond with gametangia and so-called paraphyses. ""/i- 



» 5. Lower part of a hair. *"%. 



Lithoderma fatiscens. Fig. 6—7. 



Fig. 6. Transverse section of a part of the frond bearing zoosporangia. ^''"/i- 

 M 7. Stand of gametangia. '""/i- 



