Insects. 



6025 



V. The " Scottish " or Northern Type contains three species, — 



Polyommatus Artaxerxes Erebia Blandina. 



Satvnis Davus 



VI. The " Highland" or Mountain Type one only, 

 Erebia Cassiope. 



It is remarkable that, of the last four, two only — Satyrus Davus and 

 Erebia Cassiope — reach Ireland, whereas all of them occur in 

 England.* When surprise is expressed at the poverty of our moun- 

 tain Fauna, it should be remembered that it is analogous to that of 

 the Scandinavian, not the European, Alps. 



If we proceed to institute a comparison between our butterflies and 

 flowering plants, as to the respective proportions of the several 

 " Types," we shall find there are — 



In Flowering Plants, 

 according to 



Among Butterflies. Mr. Watson's Estimate. Proportion. 



British Type (23) 2-5ths or nearly 2-5ths... 2-5ths The same. 



English Type (24) ... 2-5ths nearly l-5th Double. 



Germanic Type (13)... l-5th l-15thto l-20th... Thrice as many. 



Allanlic Type (1) l-65th l-15th to l-20th... One-fourth. 



Scottish Type (3) l-20lh l-20th The same. 



Highland Type (1) ... l-65lh M5th One-fourth. 



So that the greatest contrast is presented by the striking preponde- 

 rance of the " Germanic " and " English " Types among the insects : 

 on the other hand the " Atlantic " element (which in plants nearly 

 balances the " Germanic") is in the butterflies quite insignificant, and 

 the " Highland " is equally small. 



The same thing becomes still more evident on adding together the 

 " Germanic" and " English" sections, as they amount to more than 

 one-half of the whole number against a quarter in plants : from which 

 it seems reasonable to conclude that our butterflies are much more 

 unequally and locally distributed than our flowering plants. That 

 the insects are also much more influenced by a warmer tempera- 

 ture is plain, both from the higher numbers of southern species and 



* Supposing the English P. Salmacis to be a mere variety of P. Arta- 

 xerxes. 



XVI. z 



