| Salt Range. | Germany. | |
| Base of Trias Unfossiliferous Shale and Sandstone Top Beds of Upper Productus Limestone | Passage Beds into Trias | |
| Cephalopoda Beds of Upper Productus Limestone | Gypsum Beds | |
| Middle Division of Upper Productus Limestone Lower Division of Upper Productus Limestone | Zechstein (in restricted sense) | |
| Upper Division of Middle Productus Limestone | Weissliegende and Kupferschiefer | |
| Middle Division of Middle Productus Limestone | Rothliegende. |
It will be seen that in the Salt Range there is a complete passage from the Permo-Carboniferous strata through the Permian into the Trias, and the detailed work which has been carried out by Waagen and others amongst the rocks of the Salt Range must make this, for the present at all events, the type area for the marine development of the strata of Permo-Carboniferous and Permian ages.
The Permian flora and fauna. The Permian flora presents some difficulties. The flora of the Zechstein consists largely of ferns and conifers, but that of the Rothliegende of Germany has been compared with that of the Carboniferous, and if a true Permian flora of the northern hemisphere has many forms of Carboniferous affinities, the presence of the Glossopteris flora in Permo-Carboniferous rocks of more southerly regions seems to imply its origin there and slow migration northwards. It must be noted, however, that the Rothliegende has been divided by some geologists into an upper and lower division, of which the lower is actually referred to the Carboniferous system. All that can be now said is, that our knowledge of the floras of Permo-Carboniferous and Permian times is still incomplete, and that the difficulties will no doubt be cleared up as the result of further work.
The invertebrate fauna of the north-west European Permian deposits is chiefly noticeable on account of the paucity of species, though individuals are often abundant. The shells are also sometimes stunted and occasionally distorted. These characters bear out the supposition that the aqueous deposits were laid down in inland seas of Caspian character and not in the open ocean. Polyzoa, brachiopods, and lamellibranchs predominate, but other groups are found. The vertebrates consist of forms of fish, amphibia and reptiles, and the Permian rocks are the earliest strata in which the remains of true Reptilia are known to occur with certainty. The Reptiles belong to the orders Anomodontia (Theromora) and Rhynchocephalia, of which the former is exclusively Permian and Triassic, while the latter is abundant in the strata of those periods, but is represented at the present day by the genus Sphenodon of New Zealand. The Amphibia belong to the order Labyrinthodontia which ranges from Carboniferous to Lower Jurassic, but the members of the order are most abundant in Permian and Triassic strata, and these periods may be spoken of as the Periods of Labyrinthodonts.
A few words must be said of the fauna of the truly marine Permian beds. It is much richer than that of the abnormal deposits of north-western Europe, and its study is important as furnishing another link between Palæozoic and Mesozoic life. Many Palæozoic genera pass up into the Permian rocks, and, as will be ultimately seen, several occur in those of the Triassic system, and one or two even in the basal Jurassic strata, though Mesozoic forms predominate in the Lower Jurassic Rocks, and there is a fairly equal admixture of forms usually considered as Palæozoic and of those generally regarded as Mesozoic in Triassic rocks, while the Palæozoic forms still predominate over the Mesozoic in the Permian strata. Along with these characteristic Palæozoic genera, it is interesting to find representatives of more than one genus of the tribe of Ammonites, which is to take so prominent a place in the fauna of the Mesozoic rocks, amongst the true marine Permian sediments of India and other areas. The announcement of the contemporaneity of ammonites with fossils regarded as exclusively palæozoic was received with considerable doubt, but this contemporaneity is now clearly established, and need not be regarded as in any way anomalous.
With the deposition of the Permian rocks, Palæozoic time comes to an end, but as already remarked there is no marked and sudden change to characterise it. Had our classification been originally founded on study of the Indian Rocks instead of those of Britain, and similar terms adopted, the line of demarcation between Palæozoic and Mesozoic rocks would probably have been drawn below the Permo-Carboniferous deposits, and if it had been based on study of other areas, perhaps elsewhere. The palæontological break is purely local, and it is of the utmost importance that it should be recognised as such, and that it should not be considered that division into Palæozoic and Mesozoic implies some great and widespread change which occurred between the times covered by the deposits of each of these great divisions[97].
[97] The Permian Fossils of Britain are described by Professor King in the Monographs of the Palæontographical Society (the Brachiopods by Dr Davidson in the Monographs of the same Society). For a general account of the marine type the student may consult the second edition of Messrs Medlicott and Blanford's Geology of India. For information concerning the Permian volcanic rocks see Sir A. Geikie's Ancient Volcanoes of Great Britain.
THE TRIASSIC SYSTEM.
Classification. The term Triassic has been applied to these rocks on account of the threefold division into which those of Germany naturally fall. These three divisions are:—