CYCADOFILICALES 9 



cannot spend the time or cover the ground so thoroughly as it is 

 covered within the paleobotanizing range of a well-financed univer- 

 sity. It is practically certain that a much more extensive geographic 

 distribution can be plotted when all the evidence is as complete as it 

 now is for Great Britain; and even the geological distribution may go 

 down a little deeper and extend up a little higher than available ma- 

 terial now indicates. 



There is no doubt that the Cycadofilicales reached their greatest 

 development in the Upper Carboniferous (Pennsylvanian) . Their 

 greatest display in this period gave the name "Age of Ferns." That 

 they go back through the Lower Carboniferous and far down into the 

 Devonian is certain; but just when they first appeared will probably 

 never be determined. In the other direction members can be identi- 

 fied with certainty in the Permian, probably in the Triassic, and 

 there are suggestions of even Lower Jurassic forms; but neither here 

 nor in the Triassic has there been any complete assembling of root, 

 stem, leaf, microsporangia, and seed. 



The best evidence for the presence of Cycadofilicales in the De- 

 vonian is furnished by Eospermatopteris. About 50 years ago a flood 

 in the Catskill region of New York tore away soil and rocks and ex- 

 posed fossil trees standing where they had grown. In the museum at 

 Albany, New York, there is a reconstruction showing a shore of the 

 Devonian sea, with these trees as the dominant vegetation. They 

 were referred to the genus Psaronius, a well-known genus of the later 

 Carboniferous; but a more thorough study showed that there are 

 two kinds of reproductive organs which are better interpreted as mi- 

 crosporangia and seeds. It is to be noted that the seeds are small, only 

 5 or 6 mm. in length. The trees reached a height of more than 30 feet, 

 a diameter of 3 feet, and had a crown of leaves 6-9 feet long; so that 

 it had the appearance of a stout tree-fern. There are fragments of 

 other forms which may belong here, but the evidence is not so strong. 



In the Carboniferous the Cycadofilicales reached their highest de- 

 velopment. Associated with the giant lycopods and calamites they 

 formed a prominent part of the vegetation which finally became 

 coal. Lyginopteris, Medullosa, Heterangium, and many others have 

 become well known. It was from this vast assemblage that the Ben- 

 nettitales and Cycadales were developed. 



In the Permian, the Cycadofilicales declined, became very scanty 



