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 ac, and 346). 
Fic. 343 
Dipteris, Reinw. A-C=D. conjugata (Kaulf), Reinw. A=leaf of a mature plant. 
Bz=habit of a young plant. C=part of a fertile leaf with venation and sori. D= 
sporangia and paraphyses enlarged. Z=D. Lobbiana (Hook.), Moore. Part of a fertile 
segment with venation and sori. (A, C, D after Kunze. B, & after Diels, from Engler 
and Prantl, Vat, Pfanzenfam.) 
here seems to be only one probable way of reading these facts 
phyletically. Comparison points to Matonia and Glechenia as primitive 
