KAKATOE. 
structure, and firm, not downy, terminally. Between these several groups of 
species there is, however, complete intergradation in the size and form of 
this covert. 
“It is obvious that the Cockatoos and the Owl Parrot branched off 
from the early Psittacine stem before the reduction in the first primary covert 
began, and it is unlikely that this reduction took place independently in two 
or more groups. On this view the Cacatuidce and Stringopidce form a group, 
or two groups, equal in value to all the other Parrots combined. * This is 
contrary to Gadow’s scheme in which the suborder is divided into Tricho- 
glossidce with Nestorince, Loriince, and Cyclopsittacince, and Psittacidoe with 
Stringopince , Cacatuince and Psittacince . The Cockatoos are a strongly 
marked group. The entire absence of green or blue in any species is very 
striking, and among other characters are the presence of a crest, and, in the 
skull, a peculiar orbital ring. The arrangement suggested does not appear 
to be contradicted by any other character, and though it is here impracticable 
fco pursue the subject further, it is evident that the first primary covert should 
be considered in any future attempts to elucidate the classification of the 
Parrots.” 
Further on, in an extract I. quote in connection with Eolophus, Miller 
recognises that genus as very distinct from Cacatoes, but concludes : 
“ Mathews recognizes five segregates of the old genus Cacatoes, a degree of 
subdivision that to many will seem quite unnecessary.” It will be noted 
that Miller does not give it. as his personal opinion that the five segregates 
are unnecessary, and I am quite certain, from his very careful work ? that when 
he does criticise my subdivisions (four, not five) he will find good reasons 
for the retention of some, if not all, of these segregates. In any case I do not 
think that Cacatoes , Lophochroa and Ducorpsius can be lumped while Licmetis 
is recognised, as suggested in the second sentence of the quotation given. 
While agreeing with Miller that every item should be considered in the classifi- 
cation of birds, I cannot see any close relationship between the Owl Parrot 
and the Cockatoos, as I have already stated. 
A few notes on the distribution of the Cockatoos may prove interesting, 
and I shall here use the restricted genus names adv ocated. As regards extra 
limit al range KaJcatoe and Ducorpsius only occur, the other three genera having 
no representatives. A feature in connection with colour at once engages 
attention, as these are the pure white species with sulphur colouring on crest, 
under wings and under tail. In some extra limital species, however, orange- 
red has displaced the sulphur. KaJcatoe and Ducorpisus agree in coloration 
but differ widely in the crest formation ; the former extends into Tasmania 
167 
