[Footnote 96: It should be mentioned that some writers have inferred the evidence of glacial conditions over parts of the British area, on account of the resemblance of some of the Permian breccias to recent glacial deposits. The question is still _sub judice_. It is not necessarily opposed to the existence of desert conditions, if the mountains were sufficiently high, for the Wahsatch regions adjoining the Basin Region of N. America have been glaciated.] The extensive development of Permian and Triassic rocks with terrestrial characters in the southern hemisphere also, and the absence of newer deposits in many places, suggests that the land areas of these times in that hemisphere have largely remained such ever since, in which case, the Permo-Triassic series of movements produced a marked direct effect upon our present continental areas, and at any rate produced an indirect one upon the British land tracts. The presence of anomalous deposits of Permian age over wide areas need not be surprising, but it would be indeed remarkable if no ordinary marine type of Permian rocks was known, and the researches of recent years have proved that this type is extensively developed, in Eastern Europe, Asia, and North America, where Permian rocks consisting of limestones, with a greater or less admixture of mechanical deposits, occur in some abundance. The studies of Waagen and others in India have given us the farthest insight into the nature of these beds. Below is a general classification taken from Waagen's work:-- Salt Range. Germany. Base of Trias } Unfossiliferous Shale and } Sandstone } Passage Beds into Trias Top Beds of Upper _Productus_ } Limestone } Cephalopoda Beds of Upper } Gypsum Beds _Productus_ Limestone } Middle Division of Upper } _Productus_ Limestone } Zechstein (in restricted sense) Lower Division of Upper } _Productus_ Limestone } Upper Division of Middle } Weissliegende and Kupferschiefer _Productus_ Limestone } Middle Division of Middle } Rothliegende. _Productus_ Limestone } 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.