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83 
—there is a great resemblance in their animal and plant in- 
habitants, and many of the species are identical. Those of 
North Africa, while resembling those on the opposite shores 
of the Mediterranean, are, as a whole, widely different from those 
of the great desert. The Neotropical region—the southern part 
of the Western hemisphere—is remarkable for the variety and 
distinctness of its forms of life. Many of the characteristic 
mammals are low or archaic types, superseded elsewhere by 
higher and more specialized creatures. Many of the peculiar 
birds too belong to the lower orders, while the more highly 
specialized order—the Passerine—is but poorly represented. 
The Ethiopian region—Africa south of the Sahara—has a 
highly characteristic mammalian fauna, which includes the 
Hippopotamus, Giraffe, Zebras, Baboons, the Gorilla and Chim- 
pansee, more than seventy peculiar Antelopes, the Aard-vaark, 
Okapi, and other less known but zoologically even more interesting 
forms. 
The great island of Madagascar has a fauna and flora so peculiar 
and distinct from that of Africa, that many naturalists think it 
worthy to rank as a region by itself. The most prominent animals 
of Africa are its Monkeys, Apes. and Baboons, its Zebras, 
Rhinoceroses, Elephants, Giraffes, Buffaloes, and Antelopes. No 
one of these nor anything like them is fonnd in Madagascar, and 
yet there are about seventy known species of Malagasy mammals. 
Practically the whole of these belong to old-world primitive 
types, many of which are only known elsewhere as fossils. 
Tne Australasian region has a fauna so widely different trom 
that of the rest of the world, that the globe might with propriety 
be divided into two regions only, of which the Australasian is 
one. Cut off long ago from contact with the other great land 
masses, this region is comparatively speaking a placid backwater 
of life, where competition has been less keen, and, as a conse- 
quence, advance has been less rapid. Here survive the Kchidnas 
or Spring Anteaters, and the Ornithorhynchus, or duck-billed 
platypus, the only mammals in the world whose young are 
produced from eggs, in which regard, as well as in many 
important structural characteristics, they approximate to reptiles 
rather than to mammals as we know them. The evidence of 
fossil-bearing rocks shows that the Prototheria or egg-laying 
mammals were ousted by the Marsupials, less reptilian, but still 
of primitive organization. The Marsupials have disappeared 
from every part of the world except South America, where a few 
species of Opossum still exist, and Australia, which is their 
metropolis. 
During the secondary period Pouched mammals or Marsupials 
ranged over the whole world, but the advent of the higher 
