DE8CBIPXI0N OF A HAWK. 195 



The fourth is slightly narrowed on its outer web, about an inch from the 

 tip. 



The first quill feather is three quarters of an inch shorter than the second, 

 and the second is a quarter of an inch shorter than the third, whilst the 

 second emd fourth are equal. 



The tarsi and toes ai-e a pale yellow ; the claws a very pale horn colour, 

 and very short, small, and triflingly incurvated. The tarsi are an inch and 

 three eighths long, and a good deal compressed posteriorly. On the infeiior 

 and anterior portion of the tarsus, extending upwards from its junction with 

 the third toe, there are six scutella, the lowest being large. 



The first toe is three quarters of an inch long, and has eight scutella. 



The second one and three-sixteenths, and has ten scutella. 



The third one and three-eighths of an inch, with twenty-two scutella. 



The fourth is an inch, and has twelve scutella. 



The third and fourth, at their base, are connected by a web three-sixteenths 

 of an inch in width; viz., from the posterior angle at the junction of the toes, 

 to the anterior margin of the web. This web extends narroivly a short 

 distance along the internal edge of the third toe, terminating at the joint. 



This Hawk, which I have now described, and which is in my possession, 

 is either a variety of some of our British HaAvks, or a new species in the 

 United Kingdom. 



Varieties in plumage are not very unusual in many of our British Birds, 

 but so strange a variation as the present instance offers, has seldom, if ever, 

 been recorded in the Hawk tribe. 



Patches of white, or indeed any other colour, may occur indiscriminately, 

 or irregularly here and there, on any bird, and may be legitimately enough 

 passed over as a " lusus natures" in plumage; but, in this instance, we have 

 one side of the bird precisely similar to the other side in its variegated 

 plumage, and not in colour alone, but in position, extent, and form, there is 

 also e7itire uniformity, with the trifling exception of the extremities of the 

 tibial feathers, previously alluded to. There is the same extent and form of 

 greyish stripe extending right and left from the base of the whitish patch on 

 the Occiput. 



The wings precisely correspond, the whole of the primaries and nine of 

 the secondaiies being perfectly white on both sides of the bird. The colour 

 of the bars, and their peculiar and incomplete form on the six tail feathers 

 on one side, exactly accord with the colour, extent, and form of the six 

 feathers on the other side, whilst the outer webs on the under surface of the 

 outer feathers are alike nearly quite white. Then with regard to form of 

 feather ; the notches in the wing featlaers of this Hawk difler in position 

 from that in other Hawks, and correspond on the sides of this Hawk. Also 

 the relative length of the wing feathers differs from other Hawks, and yet 

 precisely corresponds in each wing of this Hawk. 



