1558 THE STORY OF THE UNIVERSE 



animals. Two-thirds of the Australian Mammalia 

 belong to the marsupial order, and the kangaroo, the 

 largest member of that family, surpasses in size any 

 other of its indigenous quadrupeds. The Quad- 

 rumana, pachyderms, and ruminants are altogether 

 unrepresented, nor are there any of the larger car- 

 nivora, the native dog (already verging on extinc- 

 tion) being the chief among them. In the present 

 day large numbers of the Australian population are 

 employed in rearing the domestic cattle of Europe. 

 Australia forms in all regards a distinct zoological 

 province, and its insulated position has tended, in 

 greater measure than is the case with any other part 

 of the world, to confine the distinguishing features 

 of its fauna within its own proper limits. The kan- 

 garoo family includes numerous distinct species, 

 from the full-sized kangaroo down to the kangaroo- 

 rat. But not a single one of the tribe is found beyond 

 the limits of Australia and the neighboring island 

 of Tasmania. The opossums, which belong to the 

 same order, are only found elsewhere in the New 

 World. The most remarkable, however, among the 

 members of the Australian animal world is that 

 popularly known as the duck-bill (platypus, or 

 ornithorynchus), which constitutes a puzzle to the 

 naturalist. This is a semi-aquatic creature, about 

 twelve or thirteen inches in length, with the body of 

 an otter, a bill like that of the duck, and which lays 

 eggs. As one of the tribe of Mammalia (to which, 

 by its habits, it belongs) , the platypus must be classed 

 under the head of Edentata ; while, on the other hand, 

 as being oviparous, it may be regarded as belonging 



