FOSSIL MAMMALIA. 131 



agreeing in all the details with the existing castors. The stra- 

 tum in which it was found is unknown. 



It is singular enough that among the innumerable fish that, 

 in various situations, fill the laminae of the calcareous and 

 marly schists, are found, though very rarely, some viviparous 

 quadrupeds belonging to the order rodentia. 



The most numerous and considerable have been taken from 

 the celebrated quarries of GEningen, where it was for a long 

 time imagined that no animals were incrusted but those indige- 

 nous to the country. 



Three species of rodentia have been drawn from thence: 

 one is the domestic mouse, of which M. Karg assures us he 

 has found several individuals. Another is the muscardin, 

 of which there is one individual in the cabinet of Mersbourg : 

 it is five inches long, but its limbs are wanting, and is so 

 bent and compressed, that its determination is next to im- 

 possible. 



There is a third preserved in the collection of M. Ziegler, at 

 Winterthur, which is thought to be an aperea. In short, we 

 we may with safety say that, concerning these rodentia of the 

 fissile strata of CEningen, nothing can be learned with the least 

 certainty. Let us pass on to the 



Fossil Edentata. 



As yet but one genus, and, at most, but two species, belong- 

 ing to this order have been discovered in the fossil state. But 

 this genus has the closest and strongest analogy with the living 

 genera of the edentata. The animals of which we are about 

 to treat belonged to the family of the Tardiguada, constitut- 

 ing a distinct genus, to which M. Cuvier has given the name 

 Megatherium. It comprehends two species, the megaihe- 

 Hum, properly so called, and the megalonyx. 



The skeleton of the first of these animals is known almost 

 entirely, and its examination proves that it had more analogy 

 to the sloths than to any other living beings, especially in 



K 2 



