THE BIRDS OF AUSTRALIA. 
As will be seen by the above synonymy, many genera have at times been 
proposed for members of this genus ; but the characters have always been, to 
a great extent, the ornaments which the majority of the members of this group 
assume during the breeding season. In addition to these ornaments, the chief 
feature has been size ; but all intermediate sizes can be met with, from the 
Dabchick to the Great Crested Grebe. I cannot recognise as generic, characters 
which are only possessed by the birds at certain times of the year ; and 
therefore must class all the birds together, whatever the nature of their 
breeding-plumage alone may be.* 
Distribution. Cosmopolitan. 
Note. — The above diagnosis includes the genera Podicipes, Bytes, Procto'pus, and 
Loph(Bthyia of the Handlist Birds B.M., I., pp. 113-114, and agrees with Podicipes of the 
Gat. Birds Brit. Mus., Vol. XXVI., with the exception of the species Centropelma 
micropterum, which I think can be recognised as genericaUy distinct by means of its 
curiously swollen bill, and the other characters pointed out by Sclater and Salvin 
{Exotic Ornith., II., p. 189 (1869)). 
*cf. Mathews, Nov. Zool., XVII., p. 494 (1910). 
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