THE BIRDS OF AUSTRALIA. 
allied to any other genus, while its coloration is remarkable, the vernacular 
name, Freckled Duck, well describing it. 
The subfamily FuligulincB^ or Diving Ducks, is represented by one 
member only in Australia, a species of the northern genus Nyroca^ and 
which is so closely allied that at one time I only considered it subspecific- 
ally distinct from the European type of the genus. 
The ErismaturincB, a group of specialised Diving Ducks, with a 
peculiar geographical distribution, are characterised by their narrow and 
stiff tail feathers. Two peculiar Australian Ducks were included by 
Salvador! in this subfamily, one of which is closely allied to the typical 
genus Oxyura (=ETis7tiatura), but the other, Biziura, is an extraordinary 
form which I suggest anatomical investigation will separate into a distinct 
subfamily, as its superficial features indicate no clear alliance save in 
the structure of the tail feathers with the other members of the 
EfisindtufincB. The peculiar lobe under the bill, the diverse sizes of the 
sexes and the coloration make this form unmistakable, and Ey ton’s 
anatomical notes only need confirmation to sanction its absolute divorce 
from the Eris7naturin€e while real taxonomic position may be demonstrated. 
With our present knowledge the evolution of these peculiar Australian 
AnatidcB cannot be traced, though a summary of the family may be 
acceptable. Twenty-one species and subspecies are here treated of, but 
two are quite doubtful constituents of the Australian avifauna. In the 
remaining twenty forms, seventeen genera are recognised, eight of which 
are endemic and monotypic. Of the other nine genera, four are confined 
to the near north of Australia, five having representatives in the far 
north, e.g., Europe. 
A complication as to geography may be here noted. Salvador! 
admitted the subdivision of the Family into eleven subfamilies, eight of 
which are represented in Australia. Of the three not occurring, members 
of the New Zealand avifauna are relegated to two, while only one 
member of the Fuligulince occurs there as in Australia, but that is 
referred to a different genus. Yet in New Zealand fossil deposits 
bones have been commonly found which have been even referred to these 
endemic Australian genera, in some cases specific distinction being not 
admitted. There would therefore be good grounds for supposing that 
these peculiar Australian genera — viz., Ghenopis, Anseranas, Cereopsis, 
Chenonetta, Stictonetta, and Bizium were of Antarctic origin. In the 
Introduction of my List of the Birds of Australia, p. xxi., 1913, I com- 
mented upon this apparent Antarctic element in the Australian avifauna, 
citing as probable examples the genera Tribonyx and Cereopsis. The 
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