THE BIRDS OF AUSTRALIA. 
I have re-examined these in connection with the various forms of grisola, 
and am inclined to suggest that the relationship to grisola may not be so close 
as has been considered, and that it is a case of convergence in coloration and 
external form, but at the present time series showing plumage changes are 
not at hand to determine this exactly. In the meantime the two Australian 
subspecies can be maintained. 
The two names will be : 
Muscitrea simplex simplex (Gould). 
Northern Territory. 
Muscitrea simplex riordani (Mathews). 
Melville Island. 
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