452 du. f. b. white on the [May 7, 



about their geographical distribution so complete as it is for the 

 Coleoptera. The total number of genera is 21, of which 8 are pecu- 

 liar. Of the 13 genera not peculiar, 4 have Miocene affinities, 3 are 

 very widely spread, and 6 are more or less widely distributed, but 

 there is a want of information regarding them. Of the 8 peculiar 

 genera, 4 have Miocene affinities, and 3 have relations of very wide 

 distribution, the remaining genus having African affinities. 



As the Hemiptera are specially treated of in the second part of 

 this paper, I need not discuss them at length just now. 



The supposed indigenous Arachnida belong to 13 genera, none of 

 which are peculiar. All the genera are widely distributed — many 

 very widely, reaching Australia and New Zealand. One genus is 

 Miocene, and 5 belong to families known as Miocene. 



As already mentioned, there are no freshwater fishes ; and even if 

 the sea-fishes were more extensively known than they are, the conti- 

 nuity of the medium in which they live affords so many facilities for 

 the distribution of the species, that it is not very easy to learn much 

 from them. Still we find that both the geological age and the pre- 

 sent distribution of the 7 families to which the 17 peculiar fishes be- 

 long are very great, and that, on the whole, they seem to indicate the 

 same Palaearctic origin as the other classes. 



The flora alone remains to be considered. The extratropical 

 South-African affinities of the flowering plants have been pointed 

 out by Sir J. D. Hooker. As to the cryptogams, many have a very 

 wide distribution, either as species or genera ; and while many, from 

 their geological age, have had ample time for diffusion, it would seem 

 that even at the present day cryptogams have greater facilities for dis- 

 persion than phanerogamic plants. In addition, more information as 

 to their geographical distribution is necessary before they can be 

 considered to throw very much light on the subject we are con- 

 sidering. 



The facts connected with the aboriginal fauna to which I have 

 just called attention seem to indicate that its probable origin was 

 somewhat after this manner : — 



1 . That the first settlers arrived at a very early date, and that 

 no very great additions, from outside the island, were made to them 

 from that period up to the time when man's agency came into 

 force. 



2. That they did not arrive in a body, but that the colonization 

 of the island was spread over a considerable period. 



3. That the road by which they came was not on a continuous 

 land-surface. 



4. That the colonists came from the Palaearctic region. 



I shall now endeavour to prove these statements seriatim. 



1. The first settlers arrived at a very early date. 

 As, thanks to Mr. Wollaston, the Coleoptera form the best-known 

 group of the animals of the island, we will see how they support 

 my argument. If the colonization did not take place at a very early 



