MONTAGU'S HARRIER. 143 



same ; under surface of tail-feathers dull reddish-white, with 

 four or five bands of brownish-grey ; legs, toes and claws, as 

 in older birds. 



The adult female measures nineteen inches ; the wing 

 fifteen ; the beak black ; the cere dull yellow ; the irides 

 hazel ; crown of the head and nape reddish-brown, with 

 darker brown spots ; above and below the eye a streak of 

 dull white ; ear-coverts dark brown ; back and wings dark 

 umber-brown ; rump and upper tail-coverts mixed with 

 white and orange brown ; upper surface of middle tail- 

 feathers uniform dark brown ; lateral tail-feathers barred 

 with two shades of brown ; breast, belly and all the under 

 surface of the body, light reddish brown, with longitudinal 

 marks of a darker colour ; legs and toes yellow ; claws black. 

 In very old females the general colour of the plumage is 

 lighter and the irides become bright yellow. Young females 

 have the whole of the under parts from the throat to the 

 under tail-coverts of a uniform reddish-bay, without any of 

 the darker-coloured streaks observable in the adults. 



This species exhibits not unfrequently a dark brown or 

 almost black variety, which is the origin of the Circus ater 

 of Vieillot, and has several times been killed in this country. 

 The intensity of the tint varies in individuals. Sometimes 

 the male is of a very dark smoky-grey, and the female of a 

 deep chocolate-brown with a beautiful purple gloss. Mr. 

 Newcome possesses an adult dark-coloured female shot from 

 the nest. 



Having thus described the last of the British Falconidte, 

 it may be desirable, before quitting this group, to exhibit 

 a representation of the breast-bone, or sternum, of one of 

 the types of the Family, in order to shew in the form and 

 magnitude of the principal bone, and the other bones attached 

 to it, the power of flight possessed by these birds, of which 

 the breast-bone affords good comparative indication. 



The power of flight is one of the decided characteristics 

 of the organization of the Class of Birds ; and the Family 

 of the Falconidce includes some of those birds which appear 

 to possess this power in the highest degree of perfection. 



