THE BIRDS OF AUSTRALIA. 
two genera have since been admitted by genus-lumpers, though greater 
differences are observed in the species they have lumped in other cases in 
the one genus. 
In this work I admit two genera which were not accepted in the 
Catalogue of Birds in the British Museum, Vol. XXVII., the latest mono- 
graphic account of this Order. It is noteworthy that Sundevall practically 
recognised these, a fact quite unknown to me when I reinstated the genera 
from a practical examination of the birds themselves : thus Sundevall 
stated : “ Casarca ! Eyton {rutila Pall.) scarcely differs (from Ghenalopex 
mgyptiaca). Eadjah ! Rbch. {A. radjak Garn. Coqu. t. 49) differs a little in 
the bill being broader in front, and the nostrOs situated near the base.” 
“ Leptotarsis Gould (eytoni) differs in its sharp tail-feathers, which are a 
little longer (than those of Dendrocycna)^ 
When separating Aristonetta and Nyroca from Fuligula, Sundevall 
apologised : “ We do not consider the divisions propounded to be truly 
generic.” 
Such statements clearly show the peculiar modifications existing in the 
group which prohibit the usage of any well-defined groups unless such be 
of the most restricted character. 
In Baird, Brewer and Ridgway’s “ Water Birds of North America ” 
{Mem. Mils. Comp. Zool. (Harv.), Vol. XII., 1884), this group receives 
severely scientific handling, and as the result practically monotypic genera 
are utilised. Careful detailed diagnoses of the genera occurring in the 
Northern Hemisphere are given, and in every case though the basis is 
structure, full value is given to coloration. Probably part of this was due 
to the influence of Stejneger, as this brilliant worker’s “ Outlines of a 
Monograph of the Cygninm ” was practically utilised without alteration. 
They write (p. 419) : “ The species, being very numerous, naturally fall into 
several more or less well-defined groups, which have been accorded the 
rank of subfamilies. These, however, grade so insensibly into one another, 
that it is extremely doubtful whether this rank can be maintained for 
them,” and quote Stejneger’s conclusion : “ The whole family Anatidm forms, 
as to structural features, a very homogeneous group, and intermediate links 
are ever3rwhere to be found.” 
The minute subdivision prepared by Band, Brewer and Ridgway has 
acted as a guide to most workers on this group ever since. Otherwise if 
it be conceded that aU the work has been done independently, then the 
group could be cited as a champion for the genus splitters. It maj^ be 
that its difficulty, through the variation in colour and form, has entailed 
more careful study than some other groups, and the consequent diligent 
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