PLATE 33 



Petrocelis fraitciscana Setchell and Gardner 

 Fig. 1. Cross-section of mature thallus. 



CoriophyUum expansum Setchell and Gardner 

 Fig. 2. Cross-section sliomng a portion of a nemathecium. 

 Arthrospira maxima Setcliell and Gardner 



Fig. 3. An entire mature plant. 



Hildenirandtia occidentalis Setchell 



Fig. 4. A cross-section through the upper part of the thallus passing through 

 the center of a conceptaele. 



Gaijella constricta Setchell and Gardner 



Fig. 5. A mature pilant. 



Fig. 6. A median longitudinal section through a portion of a i)lant. 



Figs. 7-8-9. Portions sho^^'ing various conditions of branching. 

 Figures all highly magnified. 



[412] 



