THE CARBONIFEROUS AND PERMIAN FLORAS. 463 



Ferns are abundant in the Permian rocks, and belong for 

 the most part to the well-known Carboniferous genera Aletho- 

 pteris, Neiiropteris, Sphenopteris, and PewpUris. There are also 

 Tree-ferns referable to the genus Psaronms. The singular 

 genus Noeggerathia (fig. 711) is represented in tlie Permian, 

 and is supposed, with more or less probability, to be a Cycad- 

 aceous plant. It has pinnate leaves, with cuneiform leaf- 

 lets, the venation of which resembles that of some Cycads. 



The Conifers of the Permian period are numerous, and 



Fig. 711.- Nccggerathia ex^Mnsa. Permian. 



belong in part to Carboniferous genera. A characteristic 

 genus, however, is Walchia (fig. 712), distinguished by its lax 

 short leaves. This genus, though not exclusively Permian, is 

 mainly so, the best-known species being the W. piniformis. 

 Here, also, we meet with Conifers which produce true cones, 

 and which differ, therefore, in an important respect from the 

 Taxoid Conifers of the Coal-measures. One of the most 

 characteristic of these is the Ullmania sclaginoides, which 



