722 MINNESOTA BOTANICAL STUDIES. 



Figure 15. Corallina officinalis L. var chilensis (Kiitz.). Merid- 

 ional section of a conceptacle, showing the tetrasporangia. Zeiss 

 2 x BB. 



Figures 16 17. Corallina Vancouver iensis. 



O I 



1 6. f. typica. 



17. f. densa. 



Figures 18-19. Corallina aculeata. 



1 8. A portion of frond. X ca. 4. 



19. A young frond found in a brackish pool high above the tidal 

 mark. 



