GROUND FLOOR. 
49 
mostly from South America, including some fine specimens of 
the great Ground Sloths, the largest of which is the Megatherium, 
^hown in the act of rearing itself on its hind legs and powerful 
tail to seize and tear down the branches of a tree, in order to 
feed upon the leaves. That this was the habit of this huge 
animal is clearly indicated by the structure of the bones and 
teeth. The mounted specimen is not an actual skeleton, but is 
composed of plaster casts of the actual bones, most of which are 
in the wall-case at the north side of the room. Of the Mylodon, 
a smaller, but nearly allied species, an almost perfect skeleton 
is exhibited in a glass case near the Megatherium, and not far 
off is the Glyptodon, a huge extinct Armadillo, enclosed in a 
solid barrel-like bony case. As these animals far surpassed in 
size their diminutive existing representatives, so the gigantic 
Australian Marsupials of the corresponding period (Pleistocene, 
or latest Tertiary), the Diprotodon and Nototherium, remains 
of which will be found in this room, greatly exceeded any of the 
■species now existing on that continent. On the other hand, all 
the mammals of the earliest geological periods of which remains 
are known, are of diminutive size, as seen in the very interest- 
ing series, mostly from the Purbeck (Upper Oolite) beds of 
Dorset, and Stonesfield (Great Oolite) of Oxfordshire, exhibited 
in one of the table-cases on the north side of the room. 
The south side of this room (right on entering) is chiefly Extinct Birds, 
devoted to the remains of extinct birds, including the famous 
lizard-tailed Bird {Archceopteryx) of the Solenhofen beds of 
Bavaria, the oldest known member of the class, presenting 
many reptilian characters, but with well-developed feathers on 
the wings and tail, the impressions of which are beautifully 
preserved in the specimen. A series of skeletons of the " Moa," 
or Dinornis of 'New Zealand, a bird in which no trace of a 
wing has been discovered, show the diversity of size of different 
members of the group, some far exceeding any existing ostrich 
and others scarcely larger than a good-sized turkey. Some 
of these remains are so recent as still to be covered with dried 
skin, and even feathers. Several- eggs are also shown ; but, large 
as these are, they are greatly exceeded in size by those of the 
jEpyornis from Madagascar, in the south-east corner' of the 
room. 
E 
