CYCADOFILICALES 3 



structures, of this form at least, had been assembled. These micro- 

 sporangia at once suggested that the sporangia heretofore thought 

 to demonSitrate the occurrence of paleozoic ferns of the Marattia type 

 mi^t be the microsporangia of pteridosperms. In this way the 

 dominant Marattia plexus has disappeared, and the question has been 

 raised as to the evidence of ferns in the Paleozoic. In any event, the 

 pteridosperms have replaced the ferns as a dominant paleozoic group. 

 Scott (56) has stated that scarcely 20 per cent of the "fern fronds" 

 of the Carboniferous offer any real evidence of being true ferns; and 

 that 30 to 40 per cent of the unassigned remainder may be assumed 

 to fall in the same ratio. In consequence of this, he suggests that 

 since the Carboniferous has been described as the " Reign of the higher 

 cryptogams," remembering that Cordaitales were associated with 

 pteridosperms, it had better be characterized as the " Reign of the 

 primitive seed plants." 



It seems impossible at present to recognize a group of pteridosperms 

 as distinct from Cycadofilices, and there is a growing impression that 

 the two groups are coextensive. As Scott (82) remarks, the pterido- 

 sperms "have proved much more extensive, and also more remote 

 from the ferns, than at first realized." Under the circumstances, 

 it would seem proper to retain for the group the older name. It 

 seems clear, also, that it should take its place as a group of gymno- 

 sperms coordinate with Cordaitales, Cycadales, Coniferales, etc., 

 for it is impossible as yet to construct a definition which would exclude 

 it from gymnosperms on the basis of characters of so high an order 

 as those which separate gymnosperms from angiosperms. For this 

 reason, we have appended to the older name the termination that 

 makes it conform to the names of groups of similar rank, and shall 

 refer to it hereafter as the Cycadofilicales (84) . 



I. The vegetative organs 



The general fernlike aspect of the Cycadofilicales was the con- 

 spicuous feature of their habit, an aspect due to their foliage (fig. i). 

 The evidence indicates that there were climbers and trees among 

 them, as well as the more usual habit among modern ferns. In 

 order to understand the combination of fernlike and cycad-like char- 

 acters exhibited by the vegetative structures of the Cycadofilicales, 



