CHAPTEE XIII. 



GEOGRAPHICAL DISTRIBUTION. THE COLONIZATION OP NEW 

 ENGLAND. 



THE four great families of butterflies are found 

 in every quarter of the globe. All are represented 

 even on the inhospitable shores of Labrador and 

 in the accidental fauna of the South Sea Islands. 

 They are, however, very unequally represented in 

 every distinct zoological province, and some of 

 the minor groups are peculiar to one or more of 

 such regions. The most striking general feature 

 in the distribution of the larger groups is the al- 

 most exclusive restriction of the sub -family of 

 Erycinids to tropical America, quite as promi- 

 nent a fact as the similar limitation of humming- 

 birds to the same region. The species of hum- 

 ming-birds are the smallest of their class and 

 number nearly four hundred, or about four per 

 cent of the known birds ; they are exclusively 

 American, and more than ninety per cent of them 

 are confined to the tropics. The Erycinids are 

 among the smallest of butterflies and number 

 nearly eight hundred species, or about ten per 

 cent of the known butterflies ; of these only 



