260 ZOOLOGICAL GAP. DENS. 



surface from the breast backwards is pure white ; and 

 the plumage of the legs is marked on the same ground 

 with transverse blackish bars. The tail is crossed by 

 four transverse black bands, of about ecpial breadth 

 with the four alternating whitish or ash -coloured 

 spaces ; its tip is of a light ash-colour. The beak and 

 claws are black, and the legs dull yellow. These cha- 

 racters are taken from the Society's specimen, which 

 has lived in this country for upwards of seven years, 

 and of the mature age of which there can consequently 

 be no doubt. 



There is, however, considerable difference in the co- 

 lours of the immature bird. A specimen in the Paris 

 Museum, which M. Vieillot suspects to be a young- 

 female undergoing a change of plumage, has the upper 

 parts mottled with brown gray and whitish, and the 

 cheeks, occiput, throat, and under part light gray, with 

 a few black feathers on the front of the neck, and some 

 large irregular black spots on each side of the shafts of 

 the tail-feathers beneath, placed on a light ash-coloured 

 ground. This description exactly agrees with the figure 

 of the Falco imperialis given in Dr. Shaw's Zoology, 

 and copied in all probability from a plate in Sonnini's 

 edition of Buffon, to which work we have it not in our 

 power to refer. M, Temminck also describes the young, 

 in its passage to the adult plumage, as having the back 

 and wings grayish fawn-colour irregularly marbled and 

 spotted with black ; the collar of an ashy fawn, more 

 or less spotted with black ; the bars that cross the legs 

 fewer in nuinber and more irregular ; all the lower parts 

 of a whitish fawn-colour mixed with darker spots ; the 

 upper surface of the tail ash-coloured, and marked with 

 small blackish spots, the places of the future bands 

 being marked by patches of black, which increase in 

 size at each successive change of plumage ; and its 



