VISCOUNT WALDEN ON THE BIRDS OF CELEBES., o7 
before characters founded on the colouring can be relied on. Another source of diffi- 
culty is the extreme variability of the plumage in the first and second years, the 
young wearing a livery greatly resembling in general characters the adult garb of Aus- 
tralian C. phasianus and its allies. It is likely that this variability is more apparent 
than real, and that each species, as in Ludynamis for instance, has special phases of 
immature plumage peculiar to itself. Happily certain characters are always present 
whereby typical specific groups can be separated from one another. The most important 
are the dimensions and the form of the bill. Three distinct groups of Asiatic Coucals 
can thus be separated ; and as Java is the only known locality where all three are repre- 
sented, we may use the Javan species as standards :— 
First, C. bubutus, Horsf., as the type of the large species, such as :—C. sinensis, Stephens, 
ex China; C. rufipennis, Illiger, India and Ceylon; C. ewrycercus, A. Hay, Malacca; 
C. borneensis, Bp., Borneo; and the very distinct C. chlororhynchus, Blyth, ex Ceylon. 
This group appears to be unrepresented in Celebes; nor has it been discovered in the 
Philippines or in Formosa. 
The second group comprises species smaller in size, with short, but proportionally 
very high bills, the diminished length of the bill making it appear disproportionately 
broad at the base. The Javan representative is C. affinis, Horsf. An identical form 
inhabits Flores; and a somewhat larger species is found in Ceram, which, if the same 
as the Amboyna Centrococcyx, must stand as C. medius, Bp., ex Miiller. A Macassar 
individual, collected by Mr. Wallace, although in young plumage, bill pale flesh-colour, 
and plumage streaked and mottled, so closely resembles Javan C. affinis in dimensions 
and form of the bill, that I cannot separate it. 
The third group consists of the smallest species, represented in Java by C. javanensis, 
Dumont, =C. lepidus, Horsf. In these the bill is a miniature resemblance of that of 
the second group. The upper tail-coverts are highly developed, or, in other words, they 
are the tail-coverts of the C. affinis group. C. bengalensis, Gm., of India; C. viridis, 
Scop., of the Philippines; C. moluccensis, Cab., ex Bernst., of Ternate, very near to 
C. javanensis, but with a proportionately longer tail; and C. dimidiatus, Blyth, =C. lig- 
nator, Swinh., of Formosa and China, come within these limits. Malaccan and Banjar- 
massing individuals scarcely differ from the Javan species; and judging from the mea- 
surements given by Professor Schlegel, representatives occur in Ceram, Sambawa, 
Bangka, Sumatra, and Amboyna. 
A Celebean example of a young bird, with a pale bill and buff-streaked plumage, 
offers no distinctive characters, either in its proportional dimensions or in the form of 
the bill, whereby it can be separated from C. javanensis. Yet it must be recollected 
that the adult bird may present characters more than enough to stamp it as distinct. 
C. rectunguis, Strickland, a perfectly distinct species, as yet only known from Malacca, 
is a miniature C. rufipennis. By its external structure it belongs to the first group. 
The bill is long and much compressed. The wings are short and much rounded, the 
VOL. VIII.—PART Ul. May, 1872. L 
