Fig. 16.
[Fig. 16] is the Pecopteris lonchitica or Mantelli, a fern abundantly found in the coal-beds of Newcastle-on-Tyne, which is indeed allied to some of the existing ferns of New Zealand, but differing from them in many of its markings. The graceful arrangement of the frond particularly distinguishes this species.
Our next figure, the Pecopteris orcopteridius ([Fig. 17]), is copied from a specimen found in the coal shale of France, as is also [Fig. 18], the Asplenites nodosus, although this singularly and prettily marked plant is frequently found in other coal districts. In the ferns of the present period we have none which exactly resemble these varieties, and they appear capable of being arranged by the artist into ornaments of an exquisitely graceful character.
Fig. 17. Fig. 18.
Of these kinds numerous varieties exist in the fossil state, in which the alternating arrangements of the fronds, and the systems of venation, present many pleasing differences. These petrified plants, which grew in the enormous deltas of our island and the Continent which now form the known coal-fields, are often preserved with a delicacy which we could scarcely have expected from the conditions of putrefaction and rapid disintegration which must have gone on around them. And not unfrequently we have singularly beautiful remains of the dissected leaves of these plants ([Fig. 19]), this being effected doubtless by the action of water on the softer portions of the leaf.