96'6 The Zoologist — November, 1867. 



Commencing with the Raptores, it may be observed that between the 

 hawks and falcons, properly so called, and the true eagles, the chief 

 distinguishing marks are the form and shape of the bill and the length 

 of the outer feathers in the wing. The bill of an eagle is comparatively 

 long, terminating in a hook, whereas that of the falcons and hawks is 

 short, and begins to bend from the base. In an eagle, the first second 

 and third feathers of the wing are shorter than the fourth and fifth ; 

 whereas in the hawks the second feather is the longest, and the first 

 and third of nearly equal length, and in the true falcons the first 

 feather is the longest. There may be exceptions to this rule, but 

 generally speaking it is sufficiently correct for practical purposes.* 



Golden and Whitetailed Eagles. — A good distinguishing character 

 in the golden and whitetailed eagles is that the golden has the legs 

 feathered to the toes, while the whitetailed eagle has the tarsus bare. 

 The number of scales on the toes also differ in each : the golden eagle 

 has three on each toe; the whitetailed has eight on the first and third, 

 and nine on the middle toe. 



Greenland and Iceland Falcons. — Perhaps no question connected 

 with the Europeau avifauna has provoked more discussion than that 

 of the three great northern falcons. To take even a glance at all that 

 has been written upon this topic would not only exceed the limits of 

 the present paper, but it would, moreover, be an unnecessary repetition, 

 inasmuch as a very able review of the subject appeared in the 'Ibis' 

 for January, 1862 (pp. 43-53), and to this we take leave to refer our 

 readers. We may, however, so far enter upon the question as to point 

 out the distinguishing characters of the Greenland and Iceland falcons, 

 since this properly falls within the scope of the present essay, and will 

 be best achieved by presenting the following short extract from the 

 able review to which we have referred : — " It is always easy to deter- 

 mine not only whether any specimen is immature or adult, but also to 

 which of the two forms it may belong. In the young of both birds, 

 the general character of the markings is that of streaks running along 

 the shaft of the feather, while in the old ones they are as invariably 

 found to be running across the shaft. This is all that is absolutely 

 necessary to distinguish between them, though other equally unmis- 

 takable signs may be observed if looked for. One of these, however, 

 the colour of the cere, legs and feet (which in the young are bluish or 

 lead-colour, but in the old birds are tinged with yellow), is not always 



* Stanley's ' History ■ f Birds,' sixth edition, p. 122. 



