THE BIRDS OF AUSTRALIA. 
Licmetis tenuirostris derby i, diagnosing “ Differs from L. t. pastinator (Gould) 
in having a much smaller bill. Type Derby, North-west Australia.” 
While accepting these there subspecies I am now doubtful of the validity 
of the genus Licmetis, as recently the consideration of the subspecies of Cacatua 
sanguinea Gould has caused a further revision of my opinions in connection 
with these birds. As already noted, osteological examination has granted 
Licmetis generic rank while denying such to Ducorpsius , Lophochroa, and 
Eolophus . I am compelled to conclude that the osteological worker is 
prejudiced by the generic values of the systematist and only rarely can he 
clearly differentiate bird genera from the osteology of specimens. To elaborate, 
if specimens of Licmetis, Ducorpsius, Cacatoes and Lophochroa are examined 
by a student of osteology he could not differentiate the genera without recourse 
to literature prepared from birdskins. Thus D’Arcy Thompson admits the 
first as a valid genus, lumping the last three, because such association was 
given in the Catalogue of the Birds in the British Museum. Certainly there 
is more difference between Lophochroa and Ducorpsius than between Ducorpsius 
and Licmetis. I have long recognised this, but my latest study tends to prove 
that the latter will be lumped later. 
Among the subspecies of Ducorpsius sanguineus is one I differentiated 
with the name distinctus. 1 proposed this name on account of its superior 
size, and it has long puzzled me, as its habitat is very close to that of the 
typical D. sanguineus, than which it is much larger. Again examining it, 
its projecting bill was noticed ; this induced a close examination of this form 
with the members of the genus Licmetis. It might be almost as well classed 
as a subspecies of Licmetis tenuirostris. The bill is shorter and less projecting, 
but otherwise it agrees in size with L. t. pastinator, and has the huge eye-space 
associated with that form. Its range is quite discontinuous so that I have 
left it as a subspecies of D. sanguineus, especially as it lacks the deep reddish 
coloration of the lores, etc. However, I am not satisfied that all these bare- 
eyed white Cockatoos are congeneric, and that in the future field work will 
enable the recognition of one species only. I have already indicated that 
Licmetis might be considered as an evolution product of Ducorpsius, and it 
would be interesting to find that the intermediate links still exist in the 
neighbouring regions. At the present time Ducorpsius sanguineus distinctus 
is almost the furthest geographical form from the two Licmetis, early so named. 
Against this we have the fact that D. s. distinctus is least allied to D. s. 
sanguineus, to which it is the nearest geographical form. 
If these two forms, Licmetis tenuirostris and Ducorpsius sanguineus , are 
valid species, not to say valid genera, they might be found occurring together 
in Australia. 
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