T 
THE BIRDS OF AUSTRALIA. 
primary is long, much longer than the secondaries and equal to the fifth 
primary ; the second, third and fourth are subequal and longest. Obviously 
Chelicutia is a valid genus distinct from Halcyon^ and the succeeding series 
show its peculiarities more clearly. 
Alcedo alhiventris Scopoh shows colour-evolution in a strange manner : 
though a larger bird, the immature show their under-surface to be very 
similar to that of Chelicutia^ the breast-streaks being prominent. The head 
is brown showing indistinctly striping, there is a brownish-white collar, the 
upper-surface otherwise brownish, even the tail ; but the back is greenish- 
turquoise, while the secondary patch is dull greenish. The legs are longer 
than in the preceding. The female differs Mttle from the immature, the head 
showing the striping still indistinctly, and the chest-streaks are becoming 
obsolete. The male has developed a bright colour : the head is distinctly 
striped : a black shoulder-patch encroaches on the secondary-coverts and 
scapulars : back and tail and secondary patch greenish-blue. Structurally 
this shows similarity to the type of Halcyon, the bill being quite hke that of 
that species, but the legs are weaker : the wing is rounded, quite unlike that 
of Chelicutia, the first primary being shorter than the secondaries and the 
ninth primary, the other primaries being not very much longer, the second, 
third, fourth and fifth being subequal and longest. This could not be placed 
in Chelicutia from structural features, though the coloration suggests its close 
relationship. Neither can it be classed in Halcyon, as its colour denies its 
close alliance and suggests the similar structure to be due to convergence 
in evolution. I therefore propose the new genus name Chelictjtona for this 
species alone. 
A stiU more puzzling species is the Halcyon semicceruleus of the 
Catalogue of Birds. The correct specific name is leucocephala Muller. The 
immature shows it to be a derivative from the ancestral stock of the 
preceding. The breast markings are dissimilar only because the shaft 
stripes have nearly entirely disappeared and the brown tips predominate : 
the abdomen is deep buffy : the throat white : the head lacks stripes, and 
the black shoulder-patch tends to extend over the scapulars as in the 
preceding : the back, secondary patch and tail bright blue, developing at 
times and places a mauve tone. The adult male has the colours clearer, 
deeper and better defined, the breast markings having disappeared. 
Structurally the bill is longer, narrower and more compressed, the feet 
are very delicate, while the wing-formula is as in the preceding. 
In view of the similarity in structure and coloration, this species 
may be classed vdth the preceding in preference to Halcyon, but it is 
possible that later anatomical characters may demand its separation. 
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