Page:Geology and Mineralogy considered with reference to Natural Theology, 1837, volume 1.djvu/202

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The remains of land Tortoises have been more rarely observed in a fossil state. Cuvier mentions but two examples, and these in very recent formations at Aix, and in the Isle of France.

Scotland has recently afforded evidence of the existence of more than one species of these terrestrial reptiles, during the period of the New red, or Variegated sandstone formation. (See Pl. 1, Sec. 17).. The nature of this evidence is almost unique in the history of organic remains.

It is not uncommon to find on the surface of sandstone, tracks which mark the passage of small Crustacea and other marine animals, whilst this stone was in a state of loose sand at the bottom of the sea. Laminated sandstones are also often disposed in minute undulations, resembling those formed by the ripple of agitated water upon sand.