PLATE 19. 



Oscillatoria splendida f . uncinata Setehell and Gardner f. nov. 



22. Tip of specimen from Oak Harbor, showing a slight tendency toward 



uncinate form. (X 1000-1500) 



23. Tip of another specimen from the same locality and of the same 



magnification, showing a spiral twist. 



24. Tip of another specimen from the same locality and of the same 



magnification, showing the extreme bending. 



Pterosiphonia arctica (J. Agardh) Setehell and Gardner comb. nov. 



25. Habit of portion of robust specimen from Unalaska. (nat. size) 

 2G. Tetrasporie branchlet. (Zeiss 2 X D) 



27. Cross section through the base of a branchlet. (Zeiss 2 X D) 



Sarcophyllis pygmsea Setehell comb. nov. 



28. Habit of a group of very young plants, showing the horizontal thallus 



with the young vertical fronds arising just within the margins, 

 (nat. size) 



29. Habit of young plant, showing the symmetrical horizontal thallus 



with two erect fronds about half grown, (nat. size) 



Fauchea Gardneri Setehell. 



30. Habit of a portion of the frond of a tetrasporie plant, showing the 



size, shape, and relative arrangement of the sori. (nat. size) 



All the figures were drawn under the direction of W. A. Setehell and 

 N. L. Gardner. Figures 28 and 29 were drawn by A. A. Lawson, the rest 

 by H. N. Bagley. 



[402] 



