GIGANTIC GROUND SLOTHS 179 
sleeps suspended from a branch, but at the same time it 
always seeks a’ position in which it can rest its body on a 
branch below parallel with the one to which it clings. 
In prehistoric times a Family of gigantic ground sloths, 
called Mrc-a-THE’RI-UMs, creatures as large as the largest 
rhinoceros, lived on the pampas of southern South America 
and also in the southern United States. Plaster casts of the 
entire skeleton of the most celebrated species (Megathertum 
cuviert), from South America, 17 feet 9 inches long, are now 
to be found in many American museums. 
