AQUILINA. 27 
wanting on most of the throat feathers, while it occupies the greater 
portion of the feathers on the lower breast and abdomen; the 
tibial plumes, vent, and lower tail-coverts are dingy reddish-buff ; 
the lesser and median lower wing-coverts are reddish-buff, more 
or less centred with brown, and the greater lower wing-coverts are 
mingled white and blackish-brown; the lineation of the lower 
surface is more obscure and ill-defined than in what I take to be 
later forms of this same stage. In the next form of this stage 
every feather of the head, nape, and upper back is brown (a 
soft hair brown), darker than the form above described, with a 
conspicuous narrow, fulvous, central stripe. All the wing-coverts 
and scapulars are tipped with fulvous or fulvous-white, the lesser 
ones narrowly, in fact with a mere spot at the tip—the larger 
ones more broadly ; the rump, back and upper tail-coverts are 
as above described ; but the tail is a dingy wood-brown, without 
any trace of bars, and broadly tipped with fulvous-white. 
The secondaries are conspicuously tipped with white or fulvous 
white ; the chin, throat, and ear-coverts are unstreaked fulvous ; 
the breast and upper two-thirds of the abdomen are a warm, 
somewhat purplish-brown, with conspicuous, well defined, narrow, 
central fulvous stripes; the lesser and median lower wing- 
coverts are more mingled with brown than in the specimen above 
described, and the larger lower-coverts are greyish-white, mottled 
with blackish-brown, and the axillaries, which, in the form first 
described, were reddish-buff, mottled with brown, are in this one 
similar to the feathers of the breast. In another form of this 
stage the head and back resemble the form first described; the 
tail and wings the second; while the chin, throat and ear-coverts 
are very pale buff, and the breast and abdomen are of the same 
color, each feather narrowly margined with the warm purplish- 
brown. 
Specimens in this stage vary greatly, independently of the 
points noted above; in the color of the thighs, vent and lower 
tail-coverts (which in some are nearly white, in others rufous 
buff), and in the extent and purity of the white, or fulvous- 
white tipping, to the tail and secondaries. The difficulty is, 
that these various differences do not go together. If the birds 
be arranged in a series, with reference to the comparative width 
of the central stripes of the breast feathers, which width varies, 
as above noticed, from less than one-fifth to nearly four-fifths of the 
total width of the feathers, and then turned back upwards, no 
corresponding progression in the lineation of the upper surface 
is observable, and, in order te obtain a regular series, according 
to the extent and amount of the lineations of the upper 
feathers, a totally different arrangement will be necessary. 
Adopting either of these arrangements, we shall still have no 
regular progression in the extent or purity of the white tipping 
of the tail, or secondaries, or in the color of the lower abdo- 
men, vent, and leg-feathers, 
