Ipswich Museum. ToL 
of the old world were represented, but by distinct species. The 
black bear of North America differed from the brown bear of 
Europe ; the bison from the aurochs, or any other bovine animal of 
Europe, Asia, or Africa. The beaver of Canada was distinct from 
the beaver of Europe; but there were some genera of the smaller 
quadrupeds quite peculiar to North America. 
When we come to compare the mammalia of South America, 
almost every aboriginal species belongs to a genus unknown in any 
other part of the world. The monkeys which abound in the tropical 
part of this continent differ from those of the old world by having an 
additional number of certain teeth, and, for the most part, a pre- 
hensile tail ; they have also a different physiognomy—the nostrils are 
wider apart, giving greater breadth and flatness to the nose: this is 
the case without exception among the South American monkeys, 
whence they are called Platyrhines in Systematic Natural History. 
All the monkeys of the Old World, equally, without exception, have 
the nostrils approximated, and they are called Catarrhines: none of 
them have the prehensile tail. This fifth member in the Platyrhine 
group gives them additional power of grasping and climbing—makes 
them even more peculiarly arboreal ; and a similar relation to a forest 
country may be traced through most of the peculiar forms of South 
American mammalia. The sloths are so expressly adapted for living 
in trees, that every other kind of life and mode of locomotion has 
been sacrificed, so to speak, to the perfection of their organization as 
climbers. Much compassion has been wasted upon their helpless 
condition when contemplated in their awkward attempt to move on 
level ground—the common theatre of the activities of mammalian 
quadrupeds. At the foot of these trees lived the races of armadillo 
and ant-eater, also peculiar to South America. Both were destined 
to feed on the countless swarms of termites that subsist on the de- 
caying timbers, and the armadillos were particularly protected by 
their bony armour from the effects of falling boughs and trees. 
In Australia the native quadrupeds were not merely distinct in 
species and genus from those in other parts of the world, but belonged 
to a peculiar division of the class Mammalia, characterized by a port- 
able nest for the young, called the ‘marsupium.” Some of these 
“marsupial ’’ animals were carnivorous, others herbivorous,—some 
terrestrial, others arboreal,—some were burrowers, others swimmers : 
among the latter was the curious Ornithorhynchus, with the tail of 
a beaver, the skin of a mole, the beak of a duck, and the spurs of a 
cock. These creatures performed in Australia all the parts which 
the other kinds of quadrupeds performed on the larger continents, 
but were of a different and lower grade of organization. New Zea- 
land was remarkable for the total absence of any aboriginal species 
of terrestrial quadruped. Those that now abound in the island had 
been imported by the colonists from Europe, and there was no 
natural obstacle to their well-bemg and increase in New Zealand. 
Finally, the Professor entered upon the question—How long has 
this geographical distribution of animals prevailed wpon the earth ? 
and showed that the results of the acquisition and determimation of 
