﻿4 Allen's naturalist's library. 



which underlies the chalk and greensands, and is collectively 

 termed the Jurassic or Oolitic system, we shall find that Mar- 

 supials, more or less closely allied to the most primitive carni- 

 vorous types now inhabiting Australia, were once widely spread 

 over Europe. As these Marsupials are quite unknown after the 

 Jurassic period, we may assume that during or soon after that 

 time they reached Australia, where they have ever since been 

 completely cut off from all the rest of the Old World, save New 

 Guinea and the islands above mentioned. 



Before leaving this part of our subject, we may refer some- 

 what more fully to the views of Dr. Wallace, as displayed in 

 his most recent work, with regard to the former connections 

 of Australia. After stating that the geological relations of the 

 western Malayan islands are undoubtedly with continental Asia, 

 he gives his reasons for considering that the very shallow seas 

 connecting the islands of the northern area indicate that not 

 only Java and Borneo, but likewise the Philippines, formed a 

 south-eastern extension of the Asiatic continent at a com- 

 paratively recent date; this connection being still more clearly 

 demonstrated by the evidence of the fauna and flora. Passing 

 over the deep seas separating this original land-mass from 

 New Guinea and Australia, we at once enter the area dis- 

 tinguished by the peculiarities of its fauna mentioned above, 

 and which, as we have said, appears to have been isolated 

 from the Asiatic continent since the Jurassic period. A study 

 of New Guinea, the Moluccas, and the islands as far as Lom- 

 bock in the north, and Tasmania in the south, seems further to 

 prove that the land of Australia was formerly much more exten- 

 sive that it is at present. So far as the eastern coast is con- 

 cerned, this is amply demonstrated by the great barrier reef, 

 which indicates the original limits of the land in this direction. 

 On the same coast, but at a greater distance from the land, 

 are several scattered islands, among which is New Caledonia. 



V 



