VI] 



PTEROPSIDA 



83 



we have something different in the way of a fructification to 

 anything known among Carboniferous plants. On the other 

 hand, that of the Psilophytic genus Broggeria (Fig. 17, p. 35) 

 has at least some superficial resemblance to that of Cephalopteris. 

 In both cases these fructifications may well arise from the 

 metamorphosis of a tuft of finely divided branchlets, and may 



Fig. 47. Aphlebiae of Pecopteris (Dacty- 

 lothecd) plumosa, (Art.), from the Coal 

 Measures, showing persistence of thalloid 

 foliage. After Zeillers lem. Paleobot. 

 (1900). 



be compared with those of Archaeopteris (Figs. 28, 2, p. 56 and 

 especially Fig. 32,' p. 60). 



It is thus clear that many of the earlier Pteropsida, like the 

 Sphenopsida, retained a sub-thalloid type of foliage. This type 

 further persisted among aphlebiae well into the Upper Carboni- 

 ferous period. The aphlebiae of Pecopteris (Fig. 47) are a case 

 in point and are of the Sphenopteridium type, whereas many 



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