120 EDENTATA. 



nearly the whole skeleton has been considered, by comparing 

 different imperfect specimens, found after three unusually dry 

 seasons, in the river Salado, running through alluvial plains, to 

 the south of Buenos Ayres. This has given rise to the not im- 

 probable "suggestion," that the long continued drought brought 

 these extinct gigantic animals to a slender stream, running be- 

 tween mud banks, and that they may have been "engulphed in 

 their efforts to reach the water." 



The Megatherium gives evidence in its remains, that it was 

 more nearly allied to the Sloths and Ant-Eaters, than to the 

 Armadillos. The skull is thought to resemble the former two; 

 the rest of the body was adapted partly to the former and partly 

 to the latter. When full grown, it is judged this enormous ani- 

 mal must have been not far from eighteen feet in length, and nine 

 feet in height. (See fig. on the chart.) The thigh bone twice 

 the thickness of the largest elephant's; the fore foot more than 

 three feet in length, and more than one in width, and terminated 

 by an enormous claw. The width of the upper part of the tail, 

 could not have been less than two feet. The entire structure of 

 this extinct animal, must have been admirably adapted for digging 

 in the earth, so as to enable it to obtain the succulent roots which 

 probably constituted the principal part of its food. Dr. Buckland, 

 in his " Bridgewater Treatise," says, " The size of the Megatherium 

 exceeds that of the existing Edentata, to which it is most nearly 

 allied, in a greater degree than any other fossil animal exceeds 

 its living congeners. The entire frame must have been an appa- 

 ratus of colossal mechanism, adapted exactly to the work it had 

 to do; strong and ponderous in its proportions, as its work was 

 heavy, and calculated to be the vehicle of life and enjoyment to a 

 gigantic race of quadrupeds, which, though they have ceased to 

 be counted among the living inhabitants of our planet, have, in 

 their fossil bones, left behind them imperishable monuments of the 

 consummate skill with whic'i they were constructed." 



Megalonyx, (Gr. piyagj megas, great ; "0$, onux, nail or claw.) 

 To the remains of this animal, this name was given on account 

 of the size of its claws. Mr. Jefferson described it from some 

 bones found in caverns in Western Virginia, and considered it to 

 be carnivorous. He supposed it the largest of unguiculated ani- 

 mals, and probably the enemy of the Mastodon. Dr. Wistar, of 

 Philadelphia, afterwards saw in the bones of the fossil foot, resem- 

 blances-to those of the Sloth. Cuvier showed that it belonged to 

 the Edentata. Professor Owen reviewed the whole subject, and 

 arranged the animal as a distinct genus. 



