190 THE MALAYAN PAPILIONIDZ AS 
richness is partly real and partly apparent. The break- 
ing up of a district into small isolated portions, as 
in an archipelago, seems highly favourable to the segre- 
gation and perpetuation of local peculiarities in certain 
groups; so that a species which on a continent might 
have a wide range, and whose local forms, if any, 
would be so connected together that it would be im- 
possible to separate them, may become by isolation 
reduced to a number of such clearly defined and con- 
stant forms that we are obliged to count them as 
species. From this point of view, therefore, the 
greater proportionate number of Malayan species may 
be considered as apparent only. Its true superiority 
is shown, on the other hand, by the possession of 
three genera and twenty groups of Papilionide against 
a single genus and eight groups in South America, 
and also by the much greater average size of the Ma- 
layan species. In most other families, however, the 
reverse is the case, the South American Nymphalide, 
Satyride, and Erycinide far surpassing those of the 
East in number, variety, and beauty. 
The following list, exhibiting the range and distri- 
bution of each group, will enable us to study more 
easily their internal and external relations. 
Range of the Groups of Malayan Papilionide. 
Ornithoptera. 
1. Priamus-group. Moluccas to Woodlark 
Island... 9 we ee ein as -. 5 species. 
2. Pompeus- group. Himalayas to New 
Guinea, (Celebes, maximum) a wed. <% 
8. Brookeana-group. Sumatraand Borneo... 1 ,, 
¥ 
