176 BRITISH BIRDS. 



Genus SURNIA. 



The Hawk Owls were first separated from the genus Stria? by Dumeril 

 in 1806, in his ' Zoologie Analytique/ p. 34, under the name of Surnia ; 

 and the Snowy Owl was separated in the year 1826 by Stephens, in 

 Shaw's e General Zoology/ xiii. pt. 2, p. 62, under the name of Nyctea. 

 In compounding a genus out of these two genera, the earliest of them, 

 which is apparently unobjectionable, has been selected ; and its type will be 

 Surma fun erea. 



The Hawk Owls have no operculum, nor are their nostrils inflated 

 characters which separate them from all other genera, except Bubo and 

 Scops, from which they may be distinguished by the absence of any 

 longitudinal streaks on the underparts, and by the absence of any con- 

 spicuous ear-tufts. 



The Hawk Owls are confined to the Arctic regions, and are conse- 

 quently less nocturnal in their habits; otherwise they differ little from 

 the other Owls, in their mode of flight, food, and nesting-habits. Their 

 eggs are pure white in colour. The Hawk Owls are circumpolar birds. 

 Only two species are contained in the genus, both of which are accidental 

 visitors to the British Islands. 



