NOTICE OF THE MEGATHERIUM. 
11 
raised from the ground, and rests entirely on ils outer edge, — a position which must have 
precluded all rapid progression 
upon the part of the animal. The 
heel-bone has the extraordinary 
length of 1 7 inches, and a circum- 
ference y)f 28 ; occupying nearly 
one half the entire length of the 
foot. The innermost of the three 
developed toes is modified for the. 
firm fixation of a powerful claw, 
the sheath measuring 13 inches in 
circumference. The total number 
of bones in the hiud-.'oot is eleven, 
forming altogether a model of mas- 
sive organic masonry. 
The Tail of the Megatherium 
strikes every observer with won- 
der on account of its enormous 
magnitude. It exceeds in its mas- 
sive strength the same member in 
any other animal which has ever 
walked upon the earth. Its verte- 
brae dwindle rapidly down from 
the first, which measures twenty- 
two inches across from point to 
point of its transverse processes, 
to the 18th, which is less than two 
inches in diameter. These pro- 
cesses, as well a-s the V-shaped 
bones (the confluent hsemapophy- 
ses — chevron bones of Cuvier) 
hanging below the first eleven ver- 
tebrae, formed the attachment for powerful muscles acting from the sides and below, and 
the neural canal, which runs through the whole, attests by its very unusual size to the 
vigorous and powerful movements of this caudal appendage. Such a tail, with a circum- 
ference of six feet at its greater end, must have been a formidable weapon in giving a side 
blow, while, bent downwards at a sharp angle, so as to rest upon the ground, it would form 
with the hind legs a very firm support or tripod, from which, as a fulcrum, the huge animal 
could effect the swaying movements of the rest of its jbody when obtaining its food. The 
extreme length of the skeleton, as mounted in the Museum, is seventeen feet and nine inches ; 
its height, from the pedestal on which it stands to the top of the spinous process of the 1st 
dorsal vertebra, is seven feet. In the table at the close are given a series of measurements of 
different bones of the Megatherium, and we have added to the list, for the sake of compari- 
son, the measurements of the same bones of an adult female elephant, as given by Cuvier in 
his Ossements Fossiles. 
