XXIV.—Ideal Landscape of the Miocene Period.
Finally, the Crustaceans include the genera Pagurus (or the Hermit crabs); Astacus. (the lobster); and Portunus (or paddling crabs). Of the first, it is doubtful if any fossil species have been found; of the last, species have been discovered bearing some resemblance to Podophthalmus vigil, as P. Defrancii, which only differs from it in the absence of the sharp spines which terminate the lateral angles of the carapace in the former; while Portunus leucodon (Desmarest) bears some analogy to Lupea.
Fig. 171.—Podophthalmus vigil.
An ideal landscape of the Miocene period, which is given on the opposite page ([Plate XXIV.]), represents the Dinotherium lying in the marshy grass, the Rhinoceros, the Mastodon, and an Ape of great size, the Dryopithecus, hanging from the branches of a tree. The products of the vegetable kingdom are, for the greater part, analogous to those of the present time. They are remarkable for their abundance, and for their graceful and serried vegetation; and still remind us in some respects, of the vegetation of the Carboniferous period. It is, in fact, a continuation of the characteristics of that period, and from the same cause, namely, the submersion of land under marshy waters, which has given birth to a sort of coal which is often found in the Miocene formation, and which we call lignite. This imperfect coal does not quite resemble that of the Carboniferous, or true Coal-measure period, because it is of much more recent date, and because it has not been subjected to the same internal heat, accompanied by the same pressure of superincumbent strata, which produced the older coal-beds of the Primary epoch.
