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). 



i-'i E 



Fi<;. 343- 



'is, Reinw. .-l-C=D. conjiigata (Knulf), Reimv. A ! .if of .1 mature plant. 

 2?= habit of a young plant. C = part of a fertile leaf with venati bri. D 



sporangia and paraphyses enlarged / . ill -I i nile 



segment with venation and sori. (./.'', /'afti-r Kun/e. /'. A altci I' , m Englei 



and Prantl, .\'af. Pflanzenfam.) 



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

 phyletically. Comparison points to Matonia and Gleichcnia as primitive 



