4 
56 
ted when speaking of this bird. But there are other differences, 
which, so far as the limited number of specimens that I have 
examined, enables me to judge, are constant. In the first 
place, the Shaheen is smaller, I have four average males before 
me, two of each species, and I find the wings of the Peregrine, 
12°25, and 12°87, while those of the Shaheen are only 11°47 and 
11:64. Then not only are the head, nape and upper back al- 
most black, far blacker than in any Peregrine that I have ever 
seen; but the cheek stripe also is blacker, and proportionably to 
the size of the bird, longer. Then, on the nape, a number, 
(greater or less) of buffy patches are always seen, owing to the 
feathers there, being buffy, with broad blackish tips, and the 
buffy bases showing through. Lastly, the white bars on the 
inner web of the first primary, are more numerots, and age for 
age, narrower in Perigrinator, than in Peregrinus. Thus in two 
specimens, one of each species, both males, and as I take it, of 
much the same age, Perigrinator has thirteen white bars, each 
averaging 0°15, on the first primary of a wing 11°47; while 
Peregrinus has only eleven bars, averaging 0°23, on the first 
primary of a wing measuring 12:5. 
From Atriceps, to which it is more closely allied, it differs in 
three important points. This latteris never quite so rufous beneath, 
as Periyrinator often is. It has no separate cheek stripe, but 
has this, the cheeks, ear-coverts, head and neck, black, all in one; 
and whereas, the true adult Perigrinator has the rest of the 
upper parts, slatey blue, almost unbarred, Africcps has them 
closely and clearly barred with dusky slatey, as in Peregrinus. 
I mentioned, when talking of the primary differences between 
Peregrinus, and Perigrinator, the rufous tinge on the lower parts 
of the latter bird, but it must not be supposed, that «// speci- 
mens show this, as markedly as others. I have one specimen, an 
adult too, the whole lower part of which, including chin and 
throat, are a pure bright (but not deep) chestnut. On the other 
hand, Col. Tytler has a fine specimen ; an undoubted Perigrina- 
tor, which has the chin, throat, and neck, im front, pure 
white; ear-coverts, and sides of neck, with only a,/ain¢ salmon 
coloured tinge, towards the tips of the feathers; breast, some 
feathers pure white, others, chiefly towards the sides, with a 
decided, but not deep, salmon tinge; centre of abdomen alone, 
pure salmon colour; vent feathers, yellowish, and only a very 
very faint yellowish salmon tinge on sides, flanks, thigh coverts, 
and lower tail coverts. But the head, nape, and upper back - of 
this bird, are positively black ; there are the buffy patches on the 
nape, and the numerous narrow primary bars, so the bird is an 
unmistakeable Perigrinator, though, (if I exeept the salmon 
