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of the articulation of the hind feet appears as if it was in- 

 tended to prevent the animal from having any power of using 

 them. Instead of the articulation with the astragalus, al- 

 lowing the foot to bend on the leg, the fibula is inserted, 

 like a pivot, in a conical pit on the top of the astragalus, the 

 foot turning round like a vane on its staff; and the foot is so 

 placed that the sole cannot be put to the ground but by 

 stretching out the leg in almost a horizontal direction. 



The toes of the animal are inclosed quite to the nails in 

 a stiff skin, which will allow only of their being bent and 

 straightened altogether ; and to add to its difficulty of motion, 

 several bones, which in other animals are always distinct, are 

 here joined tqgether. The nails, which are of an enormous 

 length, are bent, when the animal does not use them, under 

 the foot, with their convex side towards the ground. 



In the western part of Virginia is a limestone, abounding 

 with large caverns, in digging the floor of one of which, a 

 fragment of a femur, the two condyles being nearly entire, 

 a radius, an ulna, three claws, and half a dozen other bones 

 of the feet, were discovered ; one of the claws being seven 

 inches and a half long. To the animal to which these bones 

 belonged the name was given of megalonyx, from the size of 

 its claws. 



Cuvier, on examining the casts of these bones, was ena- 

 bled to determine that they were the remains of an animal 

 of a species of sloth (bradypus) hitherto unknown. The 

 bones of the fore arm are about a sixth longer than those of 

 a common ox ; and on the supposition that the other parts 

 were in the same proportion, the animal must have equalled, 

 in size, the largest oxen of Switzerland or Hungary. 



About the same time that the above remains of the 

 megalonyx were found in North America, several extraor- 

 dinary and unknown bones were found in the banks of the 

 river Luxan, about three leagues west of Buenos Ayres. 

 Bones of a similar animal were also found at Lima and at 



