GEOGRAPHICAL DISTRIBUTION OF ANIMALS 1535 



in Australia proves its mammalian population to have 

 been essentially the same in Pleistocene, if not Plio- 

 cene, times as now; only represented, as the Edentate 

 mammals in South America were then represented, 

 by more numerous genera, and much more gigantic 

 species than now exist. 



In the Miocene and Eocene tertiary deposits, mar- 

 supial fossils of the American genus Didelphys have 

 been found, both in France and England; and they 

 are associated with tapirs like that of America. In 

 a more ancient geological period, remains of marsu- 

 pials, some insectivorous, others with teeth, have been 

 found in the upper Oolite. 



Thus it would seem that the deeper we penetrate 

 the earth, or, in other words, the further we recede 

 in time, the more completely we are absolved from 

 the present laws of geographical distribution. 



GEOGRAPHICAL DISTRIBUTION 

 OF ANIMALS. WILLIAM HUGHES 



THE great division of the animal kingdom rec- 

 ognized by naturalists is that into vertebrate 

 and invertebrate animals. Vertebrated animals are 

 those which possess a spinal bone, to which are at- 

 tached ribs, constituting the framework of the en- 

 tire body. All animals of this division have red 

 blood. The vertebrate animals comprehend fishes, 

 reptiles, birds, and mammalia. This last term is in- 

 clusive of all animals that suckle their young, man 

 among the number. 



The class mammalia comprehends the following 



