CAL YPTORHYNCHUS . 
deteriorated in size. Until the osteology of these species is exhaustively 
examined and careful comparisons made, I cannot suggest the phylogenetic 
development of the forms, but it is certain that three groups are here 
determinable. Their ultimate value I cannot pretend to gauge, but at 
present I maintain each as of equal value and utilise them generically. 
The distribution of the super-group is interesting and worthy of remark, 
being confined to Australia. No species occur in New Guinea, though it 
reaches as far north as Cairns in North Queensland and also occurs on 
Melville Island, Northern Territory. When we consider the groups, for which 
I will here utilise the generic names, it is found that Calyptorhynchus has 
the most extensive range, being found all over Australia, as far north as 
Cairns in Queensland and on Melville Island, and throughout North and 
West Australia, also occurring in Central Australia and all down the East 
Coast into Victoria, but it does not penetrate into Tasmania . This last item 
is very striking. 
Zanda is the name I proposed for the narrow-billed forms. Two 
species are recognised, an Eastern and a Western one. No intermediates 
are yet known, but it is possible such may yet be found. The Eastern species 
ranges from Cairns, Queensland, down the east coast into Tasmania , and 
also westward into South Australia and on to Kangaroo Island. It is not 
known from Central Australia, Northern Territory, or North-west Australia, 
but the other species is confined to South-west Australia. The Tasmanian 
habitat of this group is noteworthy. 
The small species, which I generically named Harrisornis, has the most 
restricted range, being confined to the very south of South Queensland, 
New South Wales, Victoria, South Australia and Kangaroo Island. Though 
surviving on the last-named island, it has become rare on the mainland of 
South Australia and is not common in Victoria. It does not occur in 
Tasmania nor reach West or North Australia, nor is it known from Central 
Australia. 
Consideration of osteological features in conjunction with the above 
geographical data might lead to a reconsideration of the relationships of 
these species to the White Cockatoos; and it may be that these are not so 
closely allied as has been usually considered. I have differentiated the 
Black Cockatoos with sub-family rank, still retaining them in the Kakatoeidse; 
but am of the opinion they may prove to be more distantly related. 
I cannot see any external resemblance to Strigops , though a relationship 
of the White Cockatoos to this genus has been suggested. As already 
remarked, I consider Pezoporus, Geopsittacus and Melopsittacus the Australian 
representatives of the Neozelanic Strigops , and I do not class the Cockatoos 
VOL. VL 
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