FLOOR.] 
FOSSILS. 
183 
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 Glyptodon. In the centre of 
the Room has been placed the cast of an entire carapace, with the 
singularly-armed tail-sheath of this animal ; and on the tops of the 
Wall Cases are considerable portions of the carapaces of species of 
Glyptodon. 
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, 
Asia, and America: a skull of this animal, found at Ilford, in Essex, 
having tusks of ten feet eight inches in length, has been recently set 
up in the middle of the Room. The Mastodon genus presents three 
European species (two of which are 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, none of them 
resemble 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 of 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 
number of conical prominences, which are more or less united in the 
transverse direction of the tooth, so as to form high ridges. 
Nearly allied to the Mastodons is the extraordinary animal the 
Dinotherium, of which the skull, lower jaws of individuals of different 
ages, and detached teeth, will be found in Wall Case No. 2, between 
the windows. Here it will be seen that the large tusks with which 
the animal was provided, instead of being in the upper jaw, are im- 
planted in the lower jaw, and are directed downwards. 
In Wall Case No. 1 are exhibited fossil remains and casts of large 
extinct quadrupeds of the Marsupial, or pouched order, which have 
been recently discovered in Tertiary formations in Australia. Of these 
the most gigantic is the Diprotodon Australis, the skull of which mea- 
sures upwards of three feet in length, and exhibits a dentition corre- 
sponding, in the number of teeth and in the shape of the grinders, 
with that of the Kangaroo, but resembling that of the Wombat in the 
large size and curvature of the front incisors. A fossil lower jaw, 
