Fig. 389: Microlestes antiquus, molar tooth. _Triassic Mammifer._—In North-western Germany, as in England, there occurs beneath the Lias a remarkable bone breccia. It is filled with shells and with the remains of fishes and reptiles, almost all the genera of which, and some even of the species, agree with those of the subjacent Trias. This breccia has accordingly been considered by Professor Quenstedt, and other German geologists of high authority, as the newest or uppermost part of the Trias. Professor Plieninger found in it, in 1847, the molar tooth of a small Triassic mammifer, called by him _ Microlestes antiquus._ He inferred its true nature from its double fangs, and from the form and number of the protuberances or cusps on the flat crown; and considering it as predaceous, probably insectivorous, he called it _Microlestes_ from micros, little, and lestes, a beast of prey. Soon afterwards he found a second tooth, also at the same locality, Diegerloch, about two miles to the south-east of Stuttgart. No anatomist had been able to give any feasible conjecture as to the affinities of this minute quadruped until Dr. Falconer, in 1857, recognised an unmistakable resemblance between its teeth and the two back molars of his new genus _Plagiaulax_ (Fig. 306), from the Purbeck strata. This would lead us to the conclusion that Microlestes was marsupial and plant-eating. In Würtemberg there are two bone-beds, namely, that containing the Microlestes, which has just been described, which constitutes, as we have seen, the uppermost member of the Trias, and another of still greater extent, and still more rich in the remains of fish and reptiles, which is of older date, intervening between the Keuper and Muschelkalk. The genera _Saurichthys, Hybodus,_ and _Gyrolepis_ are found in both these breccias, and one of the species, _ Saurichthys Mongeoti,_ is common to both bone-beds, as is also a remarkable reptile called _Nothosaurus mirabilis._ The saurian called _Belodon_ by H. von Meyer, of the Thecodont family, is another Triassic form, associated at Diegerloch with Microlestes. TRIAS OF ENGLAND. Between the Lias and the Coal (or Carboniferous group) there is interposed, in the midland and western counties of England, a great series of red loams, shales, and sandstones, to which the name of the “New Red Sandstone formation” was first given, to distinguish it from other shales and sandstones called the “Old Red,” often identical in mineral character, which lie immediately beneath the coal. The name of “Red Marl” has been incorrectly applied to the red clays of this formation, as before explained (p. 38), for they are remarkably free from calcareous matter. The absence, indeed, of carbonate of lime, as well as the scarcity of organic remains, together with the bright red colour of most of the rocks of this group, causes a strong contrast between it and the Jurassic formations before described.