4 R. W. SHUFELDT, 
in life, and the wide differences of opinion existing at the present 
time relative to their position in the system and their affnities, — 
it would seem that a more extended knowledge of them, in the 
more important of these several respects, would be a welcome con- 
tribution to anserine ornithology. It was this task that I set my- 
self when I undertook the present paper. 
Upon inquiry, I found there were. no skeletons of the United 
States forms of Dendrocygna in any of our public museums, beyond 
the imperfect one in the collections of the U. S. National Museum, 
which is the one I figured and cited in a previous paragraph. My 
desiderata in this respect have been finally met by Mr. F.B. Aru- 
STRONG of Brownsville, Texas, who collected 5 specimens of these 
birds in that state, and with great courtesy and generosity placed 
them all at my disposal to be used in the present connection. From 
these I prepared, with his consent, disarticulated skeletons of both 
species and both sexes of D. autumnalis and D. bicolor; and when 
I refer to skeletons of these species in what follows, it is understood 
that the references are to the ARMSTRONG specimens, unless the one 
in the U. S. National Museum is designated. 
In the collections of the Department of Birds of the U. S. 
National Museum are many skins of every known species of Dendro- 
cygna, — there being more or fewer of the different forms with 
respect to the representation in any particular case. There is also 
a very considerable collection of the skulls and skeletons of a great 
many different species of swans, geese, ducks and their allies in the 
same Department. To all this material I have been given the freest 
possible access and use by the Museum authorities, and for this 
assistancee my grateful acknowledgments are here tendered. For 
more than this, however; for all such material, both skins and 
skeletons, as I desired to use at my home for the purpose of making 
illustrations and special comparisons, were selected by me and sent 
to me by the Museum. 
For these latter kindnesses I am especially indebted to 
Dr. Cuartes W. RıcHumonD of the Department of Birds of that in- 
stitution, and to his assistant, Mr. J. H. Rırey, and I take this 
opportunity to thank them for their prompt attention to my needs. 
All the figures illustrating the present contribution were made 
by myself from the material just referred to, — that is, the ArMm- 
STRONG skeletons and what was loaned me by the U. S. National 
Museum. Specimens will be referred to by their museum numbers 
