MEGATHERIUM. 161 
It remains to consider, of what use this cuirass 
could have been to the gigantic animal on which 
it probably was placed. As the locomotive 
organs of the Megatherium indicate very slow 
powder of progression, the weight of a cuirass 
would have afforded little impediment to such 
tardy movements ; its use was probably defen- 
sive, not only against the tusks and claws of 
beasts of prey, but also, against the myriads of 
insects, that usually swarm in such climates as 
those wherein its bones are found ; and to which 
an animal that obtained its food by digging 
beneath a broiling sun, w^ould be in a peculiar 
refers without doubt to the Megatherium ; other portions of it, 
and also many bones from the same district, he assigns to other 
animals. A similar admixture of bones and armour, derived 
from more than one species of animal, bearing a bony cuirass, 
is found in the collection made at several and distant points of 
the country above Buenos Ayres, by Mr. Parish. Although no 
armour was found with the fragments of the large skeleton, 
in the bed of the Salado, the rough broad flattened surface of a 
part of the crest of the ileum of this skeleton, (see PI. 5, Fig. 2. 
r, s,) and the broad condition of the summit of the spinous pro- 
cesses of many vertebrse, and also of the superior convex portion 
of certain ribs on which the armour would rest, afford evidence of 
pressure, similar to that we find on the analogous parts of the 
skeleton of the Armadillo, from which we might have inferred 
that the Megatherium also was covered with heavy armour, even 
had no such armour been discovered near bones of this animal 
in other parts of the same level district of Paraguay. In all these 
flattened bones the effects of pressure are confined to those parts 
of the skeleton, on which the armour would rest, and are such 
as occur in a remarkable degree in the Armadillo. 
GEOL. M 
