MATONIA-DIPTERIS SERIES 



619 



size and shape, and their individuality is often lost, so that nearly the whole 

 of the lower surface of the frond appears as though densely covered with 

 a mass of sporangia (Figs. 343 A c, and 346). 



FIG. 343. 



Dipteris, Reinw. A-C = D. conjugata (Kaulf), Reinw. ^=leaf of a mature plant. 

 .5=habit of a young plant. C = part of a fertile leaf with venation and sori. D = 

 sporangia and paraphyses enlarged E = D. Lobbiana (Hook.), Moore. Part of a fertile 

 segment with venation and sori. (A, C, D after Kunze. B, E after Diels, from Engler 

 and Prantl, Nat. PJlanzenfain.} 



There seems to be only one probable way of reading these facts 

 phyletically. Comparison points to Matonia and Gleichenia as primitive 



