64 
Birds of Celebes: Falconidae. 
of the under surface of the primaries is, of course, greater than is seen when 
the specimens are compared with E. coeruleus. Count Salvadori identifies his 
Sumatran specimens with E. hypoleucus ( 15, 27); it is impossible to do this 
with these birds (Nr. 6740, Dresd. Mus.) which we propose to call provisionally 
E. coeruleus — axillaris, an intermediate form. 
As specimens of E. axillaris have been reported from Java (Gould II and 
Gurney 18), these perhaps belong to the same intermediate form, which may 
in fact link together E. coeruleus of Europe — - India and E. axillaris of Australia. 
Among the 17 examjDles in the Leyden Museum there is one from Java 
which has the wings nearly as black below as the Sumatran birds (q^; Voy. 
Diard, Cat. Nr. 6); two others from Java and one from Manado (Faber) have 
the primaries below blackish with the basal part white; another from Banjer- 
massing, Borneo, is a true hypoleucus. These form, in fact, transitions between 
the Sumatran birds and six others from Java and Celebes, which have the under 
wing- coverts and under surface of quills nearly all white and are the true 
hypoleucus. 
It thus appears probable enough that we have not to do with several 
species, but with a set of subspecies of one form, and that E. hypoleucus is very 
closely related to, and probably only subspecifically distinct from, E. coeruleus 
(Desf.) known from S. E. Europe, Africa, India to the Malay Peninsula (Hume, 
Str. F. VIII, 45). 
The form hypoleucus is a rare, or very local, bird in Celebes, as also, 
apparently in Borneo: no specimens have been included in the large collections 
made of late years in North Celebes, from which locality the single specimen 
of Forsten in the Leyden Museum and that more recently obtained by Faber 
appear to be the only ones on record; nor was it represented in the collection 
formed by Dr. Platen near Macassar in 1878. 
Its food consists largely of lizards, though doubtless, like E. coeruleus in 
Ceylon, it devours coleoptera and rats and mice as well (Legge, B. Ceylon, 87). 
In India the latter species, like E. axillaris Lath, of Australia, lays three or 
four eggs; but, considering its rarity in Celebes, it is probable that E. hypoleu- 
cus breeds more slowly than these, if it is stationary there. 
Gould {II) remarks that there is not a more distinct and better defined 
group of Hawks than those forming the genus Elanus, which occurs both in 
the Old and New Worlds. Its occurrence in two species in Australia, and its 
absence, so far as is known, in Papuasia and the Moluccas is worthy of note. 
GENUS PERNIS Ouv. 
The Honey-buzzards are of medium size and easily recognised by their 
feathered lores; the bill is weak, tapering, not strongly hooked, the culmen 
rounded, tomia not festooned, the cere very large, occupying two-fifths of the 
exposed culmen, the nostrils oblique, covered posteriorly by an operculum of 
