199 



251 



setose sporangia and thinner texture; the doubtful forms enumerated below agree 

 with D. nicaraguensis in having glabrous sporangia and firmer texture. 



Fig. 41. Base of normal pinna (X ^.'5) and segments (x I'/i) from the middle of a pinna of 

 a. D. megalodus (Schk. Urb. — b. D. leucophlebia (Christ) C. Chr. — c. O. tristis (Kze.) 

 O. Ktze. — d. D. nicaraguensis (Fourn.) C. Chr. — e. Segment oï D. Schajfneri (Fée) (x V\-i) 

 from the type with a fragment showing three different indusia and a fragment of the 



hairy form (x 4|. 



