The geological formations described are succeeded in the ascending order by the PERMIAN system of deposits—a term borrowed from the department of Perm in Russia, where the strata cover an area about twice the size of France. This constitutes the new red sandstone of English geology, and has many equivalents in other countries. Thus, in the lower division of the group or true Permian, there occurs the Zechstein and Lower Bunter series of strata: in the upper or triassic division, the equivalents are the Upper Bunter and Grés Bigarré, or variegated sandstone, the Muschelkalk and Keuper of French and German authors. The system is largely developed in America, Africa, India and China; where, as in Britain, the deposits are of extremely varied mineral characters, consisting of grits, sandstones, marls, limestones, gypsum, and rock-salt, each presenting its own family types of vegetable and animal life. The new red sandstone extends across England without interruption, through the medial or central counties, and ranges nearly north-east by south-west. The two great divisions of which it consists are everywhere well marked, the dolomitic or magnesian limestone forming the base, and giving character to the lower permian group; the upper triassic group is sufficiently distinguished by the rock-salt deposit which is wholly included in this part of the formation. Each, too, has its own peculiar set of fossils. Those of the former are allied to animals that flourished during the carboniferous period; two genera of fishes, the palæoniscus and pylopterus, are common to both. The fauna and flora of the triassic group are regarded as entirely new, neither borrowing from nor imparting anything to illustrate the organisms of the older families of rocks. The one series of strata thus represents the coming of a new, the other records the departure of a past state of things.