PREFACE. IX 



This volume is arranged on the same plan as those of 

 the " Shore Birds ' and " Gallinaceous Game Birds," 

 now pretty familiar to my readers. The species, how- 

 ever, which are contained in this book are fairly well 

 known to most people, at all events the males are; but as 

 the females of different kinds often resemble each other 

 closely, I have endeavored in the Keys, when necessary, 

 to draw comparisons between them and call attention to 

 their most marked characteristics. In the arrangement 

 of the Family, occasionally in the selection of genera 

 necessary to designate the different groups, and in cer- 

 tain cases also, in the choice of specific names, as well as 

 in the general disposition of the species, I have found 

 myself obliged to depart widely from the method adopted 

 in the A. O. U. Check List, which seems in a great degree 

 to have been constructed without sufficient consideration 

 of the affinities the North American Anatidae might pos- 

 sess to the exotic members of the Family. Of course no 

 natural arrangement is possible, for none exists, but I 

 have endeavored to bring together those groups which 

 were most in accord and produce a proper order of suc- 

 cession, although fully aware that gaps occur. 



No birds vary more, even if as much, in their relative 

 dimensions, as do the members of this family. Not only is 

 there great divergence among the species of a genus, but 

 also even among those which are members of the same 

 species. In fact it is not easy to find any two Ducks or 

 Geese which are exactly alike in ajl their measurements. 

 To ascertain how great these differences are, it is only 

 necessary to consult Mr. Ridgway's " Manual," when it 

 will be seen that for a large proportion of these birds an 

 average measurement is given, instead of an exact one, 

 and I have found so much variation existing that in 

 many cases, when the dimension of a species is recorded, 



