FLOOR.] 
FOSSILS. 
83 
and whilst in that position could freely use its flexible arms, and the 
large claws with which its fore-feet were provided. 
The affinity of this animal to the existing Sloth is evident, from 
the structure of the skull, blade-bone, &c. ; the teeth are the same 
in number, kind, structure, mode of growth, and mode of implanta- 
tion, as in the Sloth, whence the similarity of food may be inferred ; 
but the different proportions and colossal bulk of the Megatherium 
indicate that instead of climbing trees, like the Sloth, it uprooted and 
tore tbem down, to feed upon the leaves and succulent brrtuches. 
This skeleton is composed, in part, of casts of bones in the Museum 
of the Royal College of Surgeons, brought from Buenos Ayres, by Sir 
Woodbine Parish, and, in part, of casts of bones of the same species 
and size in the British Museum. In the Wall Cases between the 
windows is deposited an extensive series of the bones of different in- 
dividuals of the Megatherium, all of which are from the region of 
Buenos Ayres. On the stand with the Megatherium is placed a por- 
tion of a carapace or shell of a species of Glyptodon, an extinct genus 
nearly allied to the Armadillos, and of which several species have been 
discovered in South America. In some of these species the carapace 
must have been from ten to twelve feet in length : in all, as in the 
smaller species here exhibited, it was devoid of those " bands " or 
"joints " which give it flexibility in the small existing Armadillos. 
In the Wall Case, at the end of the room, may be seen the tail, 
with the bony sheath, of two of the largest kinds of Ghjptodon. 
The Elephant remains exhibited in the Wall Cases opposite 
the windows have been referred by Dr. Falconer to nine species; 
viz., three European, and six Indian ; but of the European species 
one (the Mammoth) is common to the northern parts of Europe, 
iVsia, and America. The Mastodon genus presents three European 
species (one of which is found in England), three species from 
India, one from North America, and one from South America. 
The Mastodon of which the entire skeleton is mounted in Room VI. 
is of the North American species (Mastodon Ohioticus). All these 
species of Elephant are extinct ; that is to say, not any of them 
resembles either of the two living species, the African and Asiatic 
Elephants ; and of the genus Mastodon there is no living representa- 
tive. The European Mastodons are found in strata which are more 
ancient than those which contain the Elephant remains ; but the 
Indian species of Mastodon were coeval with the fossil Elephants from 
the same country. The two genera, Elephas and Mastodon, have 
much resemblance in most of the characters exhibited in their skele- 
tons, but they differ considerably in their dentition. In the Elephant 
the grinding tooth is made up oif a number of flattened plates cemented 
together, each plate being enclosed by enamel ; the enamel being con- 
siderably harder than the other substances which compose the tooth, 
wears less readily, and hence projects in the form of transverse ridges 
on the crown of the tooth, which has been subjected to much attrition. 
The crown of the tooth in the Mastodons presents, before it is worn, a 
D 
