182 



COLUNS AND HEKVEY. 



PLATE VI. 



Halymenia pseudofloresia Collins & Howe. 

 Figure 36. Whole frond, | nat. size. 



HalsTnenia bermudensis CoUins & Howe. 



Figure 37. Whole frond. If X 1. 



Griffithsia tenuis Agardh. 



Figure 38. Tip of tetrasporic branch. 160 X 1. 

 Figure 39. Node with antheridia. 300 X 1. 



Habit figures were drawn from herbarium specimens, all others by camera 

 lucida. Figures 5, 6, 7, 9, 12, 13, 14, 15, 16, 17, 22, and 23 are by F. D. 

 Lambert; the others by A. C. Walton. 



