288 



ancestors of all Lepidoptera, and PalcBomicra, the most archaic 

 genus known, is at the present day restricted to New Zealand, 

 but must at one time have been the most dominant and highly 

 organised of its class, and by parity of reasoning has doubtless 

 arisen in northern latitudes, from whence it has in course of 

 ages been expelled by the more advanced groups that have 

 developed from it. 



Many families and genera could be named, as LibytheidcB, 

 Erycinidœ, etc., which, either from their generalised structure 

 or geographical distribution, may be assumed to be earlier in 

 development than Vanessa ; but as so little is yet known of 

 their internal organisation, this would be little more than 

 speculative probability. 



In Coleóptera, the distribution in the British Isles has been 

 studied by Mr. W. E. Sharp, and I am not aware of any similar 

 attempt to group the species geographically and to deal with 

 their universal distribution (PI. IX, fig. 8). 



In his study of the distribution of the British species, Mr. 

 Sharp also aims to demonstrate the sources from which they 

 have been derived, and with the view of showing this origin 

 more clearly, he eliminates all the introduced species which 

 now live under artificial conditions, as in bakeries, etc., and 

 also withdraws all those species which are universally diffused, 

 as affording no help in discovering the direction of the immigration. 

 The remainder he divides into two groups, the Adaptable 

 and the Unadaptable species. The Adaptable, or, as we may 

 term them, the Dominants, have their metropolis in this country, 

 in the south-east of England, extending more or less over the 

 whole of the country, but thinning out towards the north and 

 west, and rare or absent in Scotland and Ireland. These are 

 the aggressive group, and are derived from Central Europe. 



The Unadaptable species embrace three sections, and Mr. 

 Sharp assents to my terming them retreating or decadent. 



The first group has a discontinuous distribution, and is re- 

 stricted to southern and south-eastern England, and Mr. Sharp, 

 as a result of further thought and experience, is now inclined 

 to regard this group as also emanating from Central Europe. 



The second group is now restricted chiefly to the elevated 

 moorlands and mountains of Scotland and Ireland, while the third 



