358 WHITE-HEADED EAGLE 



ed comparison, conceive that in a collection of specimens there might 

 be several species. The bill remains dark until the head and tail as- 

 sume the white colour. 



In their first years individuals of this species are so very similar to 

 those of the White-tailed Sea Eagle, that one can hardly avoid con- 

 founding them. These species in the adult state can easily be distin- 

 guished, as the European bird never has the head white, although it 

 becomes of a yellowish-grey. It appears, moreover, from a comparison 

 of many specimens, that the bill and tarsi of the White-tailed Eagle 

 are considerably longer than those of the White-headed. Their scu- 

 tella do not differ materially, and their wings and tail are similar. 



It is a very remarkable circumstance, that in two adult individuals 

 of the White-headed Eagle examined, there are no scutella properly so 

 called on the anterior part of the tarsus, while in five younger birds, 

 there are five scutella. Such a difference has not been observed in 

 any other species. At the same time, however, there are adult indivi- 

 duals which have tarsal scutella. 



The following table exhibits the number of scutella on the tarsi and 

 toes of six individuals. 



Adult. Young in different stages. 



-^ — — -^ 



Anterior tarsal, 6 6 6 6 5 



Posterior tarsal, 12 10 11 14 9 10 



Hind toe, 4 4 4 4 4 4 



Second toe, 5 6 5 5 5 5 



Third toe, 13 12 13 9 13 13 



Fourth toe, 6 6 6 6 7 6 



The scutella of the White-tailed Eagle are as follows : 



Adult. Young in different stages. 



Anterior tarsal, 7 6 7 6 7 



Posterior tarsal 14 4 16 10 10 



Hind toe, 3 3 4 4 4 5 



Second toe, 4 3 4 5 5 4 



Third toe, 12 12 13 13 14 13 



Fourth toe, 7 7 7 7 6 7 



Two of these individuals are adult, and in one of them the anterior 

 tarsal scutella have been reduced to mere scales, as in the two speci- 

 mens of the White-headed Eagle mentioned above. Hence it appears 

 that in both species these scutella are liable to diminish in size, and to 



fS 



