Ch. XXII.] 



OLDEST KNOWN FOSSIL ilAMMIEEE. 



433 



a beast of prey. Soon afterwards he found a second tooth, also at 

 the same locality, Diegerloch, about two miles to the southeast of 

 Stuttgart. Some of its cusps are broken, but there seem to have 

 been six of them originally. From its agreement in general charac- 

 ter, it was supposed by Professor Plieniuger to belong to the same 

 animal ; but as it is four times as big, it may perhaps have been the 

 tooth of another allied species. This molar is attached to the matrix 

 consisting of sandstone, whereas the tooth (fig. 463) is isolated. Sev- 



Fia 4G3. 



JfieroltstcS emtiqutts, Plieninger. Molar tooth, magnified. Upper Trias. Diegerloch, 

 near Stuttgart, Wiirtemberg. 

 a. View of inner side ? 5. Same, outer side *? 



c. Same in profile. d. Crown of same. 



Fie:. 464. 



Ficr 465. 



Jiicrolestes antiquus. Piien. 



View of same molar as fig. 463. From a drawing by 



Hermann Von Meyer. 



a. View of inner side ? 5. Crown of same. 



c. Crown of the same, magnified. 



A 



,rr 





Molar of Microlestes ? Plien. 

 4 times as large as the fig. 

 463. From the Trias of 

 Diegerloch, Stuttgart. 



era! trao-ments of bone, differing in structure from that of the asso- 

 ciated saurians and fish, and believed to be mammalian, were imbed- 

 ded near them in the same rock. Xo anatomist had been able to 

 give any feasible conjecture as to the affinities of this minute quadru- 

 ped until Dr. Falconer, in 1857, recognized an unmistakable resem- 

 blance between its teeth and the two back molars of his new genus 

 Plagiaulax (see above, fig. 373, p. 383), from the Purbeck strata. 

 This would lead us to the conclusion that Microlestes was marsupial 

 and plant-eating. 



In Wurtemberg 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 

 Musckelkalk. 



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 



