Fern-like plants such as Sphenopterideae, Archaeopteris and Aneimites, with occasional arborescent Pecopterideae, are frequent; many of the genera, including Alethopteris, Neuropteris and Megalopteris, probably belonged, not to true Ferns, but to Pteridosperms; although our knowledge of internal structure is still comparatively scanty, there is evidence to prove that such plants were already present, as for example, the genus Calamopitys.
Numerous fronds such as Alethopteris Neuropteris, Mariopteris, &c., belonged to Pteridosperms, of which specimens showing structure are frequent in certain beds.
Probably many of the ferns were epiphytic. Pecopteris, Cyclopteris, Neuropteris, Alethopteris, Sphenopteris are common genera; Megaphyton and Caulopteris were tree ferns.
The cases in which such evidence is decisive are but few, namely, Lyginodendron oldhamium, Neuropteris heterophylla, Pecopteris Pluckeneti, Aneimites fertilis and Aneimites tenuifolius.