THE BIRDS OF AUSTRALIA. 
once more that colour is older than structural features. I will deal particularly 
with this item later. As many of the smaller species are American, these may 
be classed in Chcetura, proposed for an American form, and with which they 
generally agree in coloration. 
Pelasgia, Acanthylis and Acanthura are also based on American birds and 
the types of all these are superficially alike. They have not yet been genericaUy 
separated by American ornithologists, but certainly wiU be later, as anatomical 
differences are already on record in this connection. 
The extra- American species are varied in coloration and of peculiar distribu- 
tion, a peculiar series being developed in West Africa. At least three different 
Spine-tailed groups can be discriminated by means of coloration and the 
colour differences are confirmed by tail characters. These may be noted as 
typified by Chcetura ussheri Sharpe, Chcetura cassini Sclater and Chcetura 
sahini Gray. 
The first-named, C. ussheri, has a smoky -brown coloration with a white rump 
and under tail-coverts and striped throat. The first primary of the wing is 
longest, the feet are comparatively strong, while the tail is also comparatively 
long, being more than one-fourth the length of the wing, with the spines long and 
stiff. For this group I propose the name 
Tblaoanthuea 
which may be used subgenerically or genericaUy, but I cannot understand how 
it can be used in the former manner, as there does not seem to be any close 
relation known. Type Telacanthura ussheri (Sharpe). 
The second, C. cassini, differs entirely in coloration, being black above 
with a smoky throat, white upper tail-coverts and abdomen white, the shafts 
of the feathers dark. Structurally, it has very long wings with a very short 
tail with stiff short spines. The tail is less than one-fifth the length of the wings. 
No close relationship between this and the preceding group is apparent, and I 
here introduce for it the new name 
Neafrapus 
which may, as above, be considered of generic value. Type Neafrapus cassini 
(Sclater). 
The third, C. sabini, is blue-black above, the upper tail-coverts white and 
long, the tail long and square with short projecting spines : the under-surface 
has the throat dark, the abdomen light : the feet are stout for the size |of the 
bird in this group. It does not correlate with the preceding, as the tail is more 
than one-third the length of the wing. I therefore propose the new name 
Alterapus 
with type Alterapus sabini (Gray). 
Two species of small Chcetura are known from India, and these are 
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