6 
Birds of Celebes: Falconidae. 
The fine series of this Serpent-harrier before us displays great variation in 
tint; on the breast, for instance, from pale russet to dark Vandyck-brown. The 
darkest examples are probably the oldest. The specimens from North Celebes 
are, with one exception, darker than those of the southern peninsula, and 
Mr. Gurney writes that the specimen from Kema (N. Celebes) in the Norwich 
Museum “is decidedly darker than our four from Macassar, especially on the 
breast”. Two in the Leyden Museum from Pare-Pare near Macassar do not 
appear to differ from those of the north, and Mr. Hartert remarks (a 22) of 
some fresh specimens from the southern peninsula in the Tring Museum that 
the breast is much paler in some examples, darker in others. None of the 
southern examples before us appear to be old birds. The birds from Peling 
and Banggai vary in the same way, — one is Vandyck-brown on the breast, 
most of the others much jjaler. 
Outside the Celebes Province a very near ally of 8. nifipectua is found 
in Dr. Sharpe’s recently described Spilornis raja (Bull. B. O. C. 1893, no. X; 
Ibis 1893, 552, 569), a specimen of which was sent by Mr. Edward Bartlett 
from Kuching, Sarawak. This is said to be most like the Sula race, but differs 
in having the white bars of the breast, abdomen and axillaries strikingly narrower. 
From Sharpe’s measurements it would appear to have the wing of the Sula 
form (viz. 309 mm), but a shorter tail (178 mm). 
The food of Serpent-harriers consists chiefly of frogs, snakes and other Eep- 
tilia. The Indian species lay one or two eggs; most usually only one. 
The genus Spilornis is an important one in questions of geographical dis- 
tribution. Owing to the small number of eggs laid, the species do not suffer 
from overcrowding; and there appear to be no causes for its ever shifting its 
quarters. The genus is a purely Indian one, and is not found further east than 
the Sula Islands; and the close connection of these islands with Celebes is shown 
by the fact of their possessing the same species, which also — if identical — 
occurs on Siao in the Sangi Islands. 
Attention might here be called to the close similarity of the plumage of 
Circus assimilis Jard. & Selby to certain species of this genus, especially Spil- 
ornis holospilus Vig. of the Philippines.*) Mimicry is here out of the question, 
as C. assimilis does not occur in the Philippines, and the similarity must be 
taken as pointing to kinship of the two genera (see below under Circus assi- 
milis and Pernis celehensis). 
GENUS CIRCUS Lac. 
The Harriers are of slender form, with very long wings, tail, and tarsus, 
and somewhat short and not powerful toes. A more or less well developed 
facial ruff extending from behind the ear-coverts across the throat: 
’) Of. also Spilornis panayensis Steere (List B. Philip. Is. 1890 p. 7'. 
