Fig. 46.—Lepidodendron elegans.
Carboniferous Limestone. (Sub-period.)
The seas of this epoch included an immense number of Zoophytes, nearly 400 species of Mollusca, and a few Crustaceans and Fishes. Among the Fishes, Psammodus and Coccosteus, whose massive teeth inserted in the palate were suitable for grinding; and the Holoptychius and Megalichthys, are the most important. The Mollusca are chiefly Brachiopods of great size. The Productæ attained here exceptional development, Producta Martini ([Fig. 53]), P. semi-reticulata and P. gigantea, being the most remarkable. Spirifers, also, were equally abundant, as Spirifera trigonalis and S. glabra. In Terebratula hastata the coloured bands, which adorned the shell of the living animal, have been preserved to us. The Bellerophon, whose convoluted shell in some respects resembles the Nautilus of our present seas, but without its chambered shell, were then represented by many species, among others by Bellerophon costatus ([Fig. 54]), and B. hiulcus ([Fig. 56]). Again, among the Cephalopods, we find the Orthoceras ([Fig. 57]), which resembled a straight Nautilus; and Goniatites (Goniatites evolutus, [Fig. 55]), a chambered shell allied to the Ammonite, which appeared in great numbers during the Secondary epoch.
Fig. 47.—Lepidodendron Sternbergii.
Crustaceans are rare in the Carboniferous Limestone strata; the genus Phillipsia is the last of the Trilobites, all of which became extinct at the close of this period. As to the Zoophytes, they consist chiefly of Crinoids and Corals. The Crinoids were represented by the genera Platycrinus and Cyathocrinus. We also have in these rocks many Polyzoa.
Fig. 48.—Pecopteris lonchitica, a little magnified.