THE BIEDS OF AUSTKALIA. 
I conclude, therefore, that the Australian birds are larger than Celebes 
birds, in which I am in agreement with Meyer and Wiglesworth, and 
I use for them my subspecific name rogersi. 
Buller named a straggler to New Zealand Anas gracilis, but it is 
possible that this specimen came from or through New Caledonia, and it 
is not yet determined what the New Caledonian bird is ; for this reason 
I prefer to use the name given to an Australian bird which is more 
applicable. 
Having decided that N. gihherifrons and N. castaneMm are separable, 
how do they differ ? I suggest that the latter s'pecies has the male and feinale 
alike in coloration when adult. Mr. Tom Carter has recorded how he 
sexed a perfectly plumaged green-headed bird and found it to be a feinale. 
Campbell records that the bird fiushed from the nest, whence he first 
described the eggs, was in fuU nuptial plumage. It might have been a 
female. 
I have in my collection a specimen collected and sexed in Tasmania 
by H. C. Thompson, and it is a female in the green-headed stage. 
Probably the majority of collectors have fahed to sex their birds but 
simply placed ^ against aU green-headed birds without dissection. 
I have discussed this matter with Mr. Tom Carter and he acknow- 
ledges that all the birds in the mangroves in the Mid-west were green- 
headed, and also huge fiocks of birds, all green-headed, were constantly 
observed on Lake Muir. 
In the green-headed stage this bird is much larger than the Grey 
Teal and is then quite easily differentiated. How can immatures be 
separated ? is now the question. This is the problem and it cannot be 
settled by weighiug birds : some more practical mode must be suggested. 
The distribution of the two species would seem to show that the 
green-headed bird is strictly southern, the North-west Cape and north 
New South Wales being its northern limits, while the other species goes 
all over Australia and Tasmania and is the only species found north of 
the Tropics. 
The explanation of the evolution of the green-headed species cannot 
be given until the plumage stages of both species are clearly understood. 
To this end careful collections must be made where these birds are 
numerous, and especially where the two species are considered to live in 
distinct habitats. Thus Mr. Tom Carter is confident that no Grey Teal 
occur with the Green-headed Teal among the mangroves near the North- 
west Cape, and Capt. S. A. White only recognises the Grey Teal on the 
swampy lowland places as above noted. I assert that no discrimination 
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