126 
and plumbeous plumages, show rusty borders to the feathers of the 
upper parts, while besides the texture of their plumage leaves no doubt 
that they are very young birds in their first dress. 
Both adult and young exhibit the usual individual variation; the 
former varying in the greater or less bluish cast to the back and the 
bars underneath, the degree of blackness in the color of the pileum, and 
the former exhibiting tints variously intermediate between the rufous 
and brown phases. There appears to be no well-marked sexual differ¬ 
ence in plumage at any age, though the adult males seem to be rather more 
plumbeous than the females. 
The proper specific name for this species is involved in considerable 
doubt. Strickland is, we believe, the only one who has identified it 
with the Falco supercilidsiis of Linnaeus ; other authors having, for 
some reason, we know not what, discarded this name, and taken that of 
Falco Units Latham, as the first designation of the species. So far as 
the original descriptions are concerned, both of those quoted are ex¬ 
tremely inaccurate, and disagree in very important respects with the 
characters of the bird under consideration; but if there is no other clue 
to what species were meant by these authors than their diagnoses, 
Latham’s description is much more inapplicable than that of Linnaeus. 
It is as follows, the points of disagreement being italicized :— 
u F. pedibus flavis, corpore ciuereo-fusco, subtus albido fasciis nigri- 
eantibus, vertice albido. Tiny Falcon, Lath. Synop. sup. p.39. Habitat 
in Cayana ; inter nduimos numerandus; ab apice rostri ad basin caudae 
uncias sex tautum implens.” 
This is at best a very poor diagnosis of the species under considera¬ 
tion ; since, if this were the bird described, it is difficult to see why a 
bird which invariably has a uniform black or dusky vertex should have 
this portion described as white! 
Linnaeus describes his F. superciliosus as follows: — 
“ F. cera pedibus palpebrisque luteis, corpore fusco albido undulato, 
remigibus ferrugineis nigrofasciatus. Habitat in Snrinamo. Dahlberg. 
Magnitudo Picae. Corpus supra fuscum, subtus totum etiam fernori- 
bus confertim nigro undulatum. Bemiges ferrugineae fasciis nigris plu- 
ribus; sect secundariae margine posteriore albido. Cauda nigra fasciis 
duabus latis & apice cinereis. Crissum album, strigis aliquot nigris. 
Uropygium cilbo nigroque varium. Supercilia subtus nuda, promiuula. 
Lora setis nigris patentibus. Bostrum & ungues nigri. Tectrices alarum 
inferiores albae lineolis tenuissimis nigris.’ 7 
This description is, in the main, a sufficiently accurate diagnosis of the 
presen t species in the transition-stage, or in moulting from the ferruginous 
plumage, which sometimes characterizes the young, into the adult plumbe¬ 
ous stage, remnants of the first dress being the ferruginous remiges, as 
described. But the clause “rump varied with black and white 77 is mani¬ 
festly not a character of the present species, in which this part is 
uniform slaty, with, however, an indistinct white spotting beneath the 
surface, to be seen only upon disturbing the feathers. But this dis¬ 
crepancy is trifling compared with that in Latham’s description of his 
Falco Units, and, unless there is a better reason than we know of, we 
cannot see why Linn tens 7 name superciliosus should not be preferred. 
In case both these names be rejected on account of the reasons stated, 
Sparvius subniger Vieillot would be unobjectionable, since the type has 
been fully identified with this species by Pucheran. 
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