PLATE VII. 



A. DiCTYOTA, page 39, 



Fig. 1, D. dichotoma ; the )iatural size. 2, sorus, on 



a small portion of the frond. 3, vertical section of 



the same. 4, spore, containing four sporules. 5, 



fragment of the frond with scattered spores ; magni- 



Jied. 



B. Taonia, page 38. 



Fig. 1, T. Atomaria ; the natural size. 2, portion of 

 the frond, showing spores in bands and scattered. 

 3, section of the frond with spores in situ ; mag- 

 nified. 



C. Stilophora, page 39. 



Fig. 1, S. rliizodes ; the natural size. 2, fragment of 

 the frond, with sori. 3, cross section of frond and 

 sorus. 4, spore and filament or paranema. 



D. DiCTYOSiPHON, page 40. 



Fig. 1, D.foeniculaceus ; \\\e natural size. 2, portion 

 of the frond, with scattered spores. 3, spore. 4, 

 cross section of a younger portion, and 5, of an 

 older portion, of the frond. 6, cellular tissue from 

 the interior of the same ; all magnijied. 



