18/2.] RAPTORIAL BIRDS OF INDIA. 621 



the general appearance of the abdomen is fulvous white, patched 

 with black-brown. 



*' No. 2. A. crassipes is a much further advanced bird (leading 

 up to my second stage), and only a few light-centred feathers can be 

 found. Some of the secondaries, however, and the tertials are those 

 of the young bird. Numbers of the neck-hackles are still unchanged ; 

 and these are peculiarly those of the lineated stage. The tail of 

 this example is entirely changed, and is that of the adult crassipes, 

 with a broad terminal black band. Below the bird is a mixture of 

 black-brown and fulvous, the former largely predominating ; there 

 are a few light-centred feathers still left. The tibial plumes are 

 black-brown. This bird, to me, also appears to show that the fea- 

 thers change colour without a moult. My remark applies to the 

 body-feathers, and not those of the wings and tail." 



Having above referred to three well-defined stages as appertaining 

 to this Eagle (the first, of course, is lineated throughout), it now 

 remains for me to add that the second phase of plumage is black- 

 brown, with fulvous-coloured head and neck, but without any white 

 on the scapulary region (the two birds above described will even- 

 tually belong to this stage), and the third the fully adult, viz. black 

 having white scapulars, in addition to the fulvous-coloured head and 

 neck — Hume's fourth stage, under which description this Eagle has 

 hitherto been considered the true Aquila imperialis. 



I have added very considerably to my already good series of 

 Aquila crassipes in the two last-mentioned stages ; and it is interest- 

 ing to notice the appearance of these white feathers on the scapulars. 

 One youngish example has these feathers, which do not appear with 

 any degree of regularity, particoloured, one side of the shaft being 

 white, the other buff. This, therefore, favours the theory that the 

 feathers in this Eagle change colour without a moult. 



The " Striated" Eagle referred to by the Secretary in his recent 

 report on the additions to the Menagerie* is, I am pretty confident, 

 referable to my first stage of A. crassipes ; and it will be interesting 

 to watch its gradual change to maturity. 



2. Aquila bifasciata, Gray. The Double-banded Eagle. 



The double-banded bird, which is equally common with the young 

 of A. crassipes, has also been figured by Hodgson, under the name 

 of bifasciata. 



The whole chain of evidence with regard to the several stages of 

 this Eagle is also beyond dispute. First we have the typical light- 

 brown birds with double bars, sometimes white and at others fulvous ; 

 second, the uniform brown birds, a shade darker, but without bars ; 

 and third, the uniform brown birds, with the addition of a fulvous- 

 coloured nuchal patch the size of a crownpiece. Hodgson has also 

 figured a bird corresponding with this latter in every detail ; but the 

 plate does not bear any name. 



In case it may be necessary to point out the intermediate phases 

 of plumage between the above distinct stages, I need only state that 



* P. Z. S. 1871, p. 545. 



