342 KJELLMAN, THE ALG.E OF THE AKCTIC SEA. 



Lithoderma lignicola. Fiy. 8—11. 



Fi(j. 8. Piece of wood covered witli the plant. Vi- 



» y. Part of the basal layer of tlie froiid. *"7i. 



» 10. lladical transverse section of the frond. *'"'/i. 



» 11. Horizoutal tangeutial sectioii of the froiid. ^"%. 



Dictyosiphon corymbosus r. abbreviata. Fig. 12—15. 



Fbj. 12. Older specimeu bearing- zoosporangia. '/j. 



» 13. Part of transverse section of the lower part of the maiii axis of the frond. -"% 



» 14. Part of branch, bearing zoosporangia, seen superficially. '"Vi- 



>> 15. Part of transverse section of the same. ^**Vi- 



Ohörda filum. f. crassipes. Fiy. 16. 



Fig. 16. Full-grown specimen. '/j. 



Phloeospora pumila. Fuj. 17. 



Fiy. 17 . Lower part of the froud *Yith rhizines. *%. 



PLATE 27. 

 Pylaiella varia. Fig. I—12. 



Fig. 1. Part of sterile individual. *%. 

 » 2. Zoosporangia developed in different manners. ""Vi- 



Pylaiella nana. Fig. 13—15. 



Fig. 13. Vegetative part of the frond. '""Vi- 

 » 14. Part of vertical cell-row bearing two gametangia (zoosporangia multilocularia) oue, of which is void. "Vi- 

 » 15. Parts of vertical cell-rows bearing zoosporangia (?). ""Vi- 



PLATE 28. 



Monostroma saccodeum. Fig. 1—10. 



Fig. 1 — 2. Youug individuals, still cystiform. Vi- 



» 3 — 4. Older, full-grown individuals of soraewhat different habit. Vi- 



)) 3, Lowest part "of the frond, seen superficially. ^''Vi. 



» 6. Transverse section of the same part. *""/!. 



" 7. Part of the vegetative portion of the frond. *"%. 



n 8. Transverse section of the same. *"%. 



« 9. Part of the zoosporiferous portion of the froud. ''"Vi- 

 » 10. Transverse section of the same. ^'"'/i- 



