THE BIRDS OF AUSTRALIA. 
Consequently this may be the oldest form. The wing-formula is of the 
true island form, very round and showing lack of flight power. Tlius, 
the first primary is shorter than the ninth primary and secondaries, the 
others not much longer, the second equal to the fifth, the third and fourth 
longest and subequal, but the whole four very nearly the same length. 
The tail is long, but little graduated. T. youngi seems a weak form of 
T. tutus. 
T. recurvirostris is quite in agreement as to bill characters, save 
that the upward tendency is a little more exaggerated. The wing is round, 
but the wing-formula disagrees notably with the above, the first primary 
being longer than the sixth and also the secondaries, the second longer 
than the fifth, and the third and fourth longest. In coloration this 
species agrees with the Sauropatis {s. str.) group, and I have little doubt 
it is a recent island derivative of the sanctus-vagans series. Specimens 
of the latter from the northern islands show the same upturning of 
the bill, and in some cases a noticeable broadening and depression, so that 
its nearest allies would seem to be this group and not true Todiramphus. 
I propose to distinguish this species as a new genus Todalcyon. 
It is remarkable that we should have such a complex series of 
Kingfishers on these islands where true Sauropatis also occurs. Thus Sauro- 
patis sacer agrees closely with recurvirostris, save in the form of the bill, 
and I should conclude that probably this divergence is due to the different 
times at which the birds arrived at the islands, and would be a strong 
argument in favour of the greater antiquity of coloration as against structure. 
The last four species of “ Halcyon ” are extraordinarily interesting from 
the view-point of a student of colour*e volution. They are large birds, with 
peculiar style of coloration, the wing-coverts being spotted is a striking 
feature. One species has developed a short tail, as a recent feature, having 
apparently evolved from a long-tailed stock. 
The species Actenoides homhroni Bonaparte seems to show the oldest 
coloration. The immature and female appear to be much alike, and have 
the head greenish, a nuchal collar, buff bases with black tips, the wing- 
coverts green with pale fawn spots at the tips, the back turquoise, the 
long tail greenish : the under-surface, white throat, rest buffy, the breast 
feathers with black tips. The adult male has the head blue, a blue 
moustachial streak below the eyes from the bill, otherwise as in preceding, 
but with the colours clearer, the tail blue, the nuchal collar defined as black, 
buff, and black tipped, a triple colour series ; a very old male has the edges 
on the under-surface obsolete and the spotting on the upper- surface 
weaker. Structurally the bill is large, somewhat Sauropatis-Bha,ped, the 
