PLATE VI. 



A. CUTLERIA, page 35. 



Fig. 1, C. multifida ; the natural size. 2, a morsel 

 of the frond with a sorus. 4, antheridia. 5, trans- 

 verse, and 6, longitudinal, sections of the frond; 

 magnified. 



B. HALISERIS, page 36. 



Fig. 1, H. polypodioides ; the natural size. 2, morsel 

 of the frond with scattered spores. 3, small portion 

 with sorus. 4, spores ; magnified. 



C. PADINA, page 37. 



Fig. 1, P. Pavonia ; the natural size. 2, a sorus. 3, 

 spores. 4, circinate apex of the frond, with fringe ; 

 magnified. 



D. ZONARIA, page 38. 



Fig. 1, Fronds of Z. parvula, on a piece of Nullipore. 

 2, portion of the frond. 3, cellular structure of the 

 surface ; magnified. 



