Fig. 75.—Walchia Schlotheimii.
Among the Ferns characteristic of the period may be mentioned Sphenopteris dichotoma and [S. Artemisiæfolia]; [Pecopteris lonchitica] and [Neuropteris gigantea], figured on pp. 143, 144. “If we are,” says Lyell, “to draw a line between the Secondary and Primary fossiliferous strata, it must be run through the middle of what was once called the ‘New Red.’ The inferior half of this group will rank as Primary or Palæozoic, while its upper member will form the base of the Secondary or Mesozoic series.”[52] Among the Equiseta of the Permian formation of Saxony, Colonel Von Gutbier found Calamites gigas and sixty species of fossil plants, most of them Ferns, forty of which have not been found elsewhere. Among these are several species of Walchia, a genus of Conifers, of which an example is given in [Fig. 75].
In their stems, leaves, and cones, they bear some resemblance to the Araucarias, which have been introduced from North America into our pleasure-grounds during the last half-century.
Fig. 76.—Trigonocarpum Nöggerathii.
Among the genera enumerated by Colonel Von Gutbier are some fruits called Cardiocarpon, and Asterophyllites and Annularia, so characteristic of the Carboniferous age. The Lepidodendron is also common to the Permian rocks of Saxony, Russia, and Thuringia; also the Nöggerathia, a family of large trees, intermediate between Cycads ([Fig. 72]) and the Conifers. The fruit of one of these is represented in [Fig 76].
Permian Rocks.—We now give a sketch of the physiognomy of the earth in Permian times. Of what do the beds consist? What is the extent, and what is the mineralogical constitution of the rocks deposited in the seas of the period? The Permian formation consists of three members, which are in descending order—