106 Geological Society of London. 
nium of a buge animal of the size of a rhinoceros, with some modi- 
fication in the form of the skull resembling that in the Wombat. 
These fossils, of which a description will shortly be given to the 
Society by Messrs. Clift and Owen, establish the fact that the pe- 
culiar type of organization which is now characteristic of the South 
American mammalia has been developed on that continent for a long 
period, sufficient at least to allow of the extinction of many large 
species of quadrupeds. The family of the armadillos is now exclu- 
sively confined to South America and here we have from the same 
‘country the Megatherium, and two other gigantic representatives of 
the same family. So in the Camelide, South America is the sole 
province where the genus Auchenia or Llama occurs in a living 
state, and now a much larger extinct species of Llama is discovered. 
Lastly, among the rodents, the largest in stature now living is the 
Capybara, which frequents the rivers and swamps of South America 
and is of the sizeof abog. Mr. Darwin now brings home from the 
same continent the bones of a fossil rodent not inferior in dimensions 
to the rhinoceros. 
These facts elucidate a general law previously deduced from the 
relations to exist between the recent and extinct quadru 
peds of hennles for you are aware that to the westward of Syd- 
ney on the Mecquasia River, the bones of a large fossil kangaroo 
and other lost marsupial species have been met with in the ossifer- 
ous breccias of caves and fissures. 
A cavern has lately been examined at Yealm Bridge, six miles 
south-east from Plymouth, by one of our members, Lieut. Col. 
Mudge, R. E., from whose account it appears that the bones of hy- 
enas are very numerous there. They are associated with those of 
the elephant, rbinoceros, horse, and other animals usually found in 
caves. The number of fossil Carnivora, such as the hyena, wolf, 
fox, and bear, which have now been met with in districts of cavern- 
ous limestone in Great Britain, is so great, that we are the more: 
struck with the rarity and general absence of such remains in sur- 
rounding and intervening districts, over which the same beasts of prey 
must have ranged. The Pachydermata, as the elephant, rhinoceros, 
and hippopotamus, are often discovered in ancient alluvial or flu- 
viatile deposits; but had there been no caves and fissures we should 
scarcely have obtained any information respecting the existence of 
lions, tigers, hyenas, and other beasts of prey which inhabited the 
country at the same period. — 
