SPERMATOPHYTA 



57 



c. Cordaitales. 



d. Ginkgoales. 



e. Coniferales. 



f. Gnetales. 



Order A, Cycadofilicales 



A Paleozoic group of plants with fern-like leaves (Fig. 150). 

 They were often fern-like in habit, though including likewise vines 

 and trees. They were formerly thought to be ferns because of 

 the form and venation of their leaves. No sporangia, however, 



"^ ^m^ 



Fig. 18 a. — Codonotheca, one of the most singular and ancient microspore-bearing 

 fruits known. From the Pennsylvanian of Mazon Creek, Illinois. Figures 1-3 

 show the interior faces of the lobes covered with spores just as brought to view 

 when the nodules in which the fruits are embedded are split open. Figures 5-6 

 are the spores enlarged 28 and 85 times respectively, while Y\i. 4 is a restoration 

 of the flower-like fruit, natural size. (From Sellards.) 



were found on any of the leaves and hence it came to be suspected 

 that they might not be true ferns. Stems were finally found 

 in association with some of these leaves whose anatomy com- 



