OF ORNITHOLOGY 117 



FAMILY LI ANATIDAE THE SWANS 

 GEESE AND DUCKS 



Latin anatinus, " pertaining to a duck," duck-like. 



It may seem strange, to one not well acquainted with the 

 species, that all of our North American Swans, Geese, and 

 Ducks should be classed together in a single family. A little 

 careful study, however, will show how constant certain char- 

 acters are throughout all these birds, and that the deviation 

 from the typical structure could not well command a higher 

 recognition than that of sub-family. Accordingly we separate 

 the family into several groups or sub-families, and find that 

 they fit in with a nicety that shows how well they merit such 

 relative positions. Wherever one goes upon our continent, 

 north, south, east, or west, — along the seacoast or in the in- 

 terior — they find members of this family common and even 

 abundant. Again, the number of species are so comparatively 

 few that one would scarcely look for very extensive special 

 faunas for special localities ; this would render the great ma- 

 jority of these species of almost universal distribution — at 

 least throughout North America. The few of specially local- 

 ized occurrence are, usually, the rarer forms only. 



This family, as a family, is somewhat difficult of definition. 

 Its main features are : Bill with series of plates (lamellae) ex- 

 tending around the edges of both mandibles and fitting into 

 each other, when the bill is closed, like teeth — general shape 

 of bill, high and feathered (more or less) laterally at the base, 

 tapering to a flattened and wide thin tip — tough, strong, and 

 yet of somewhat elastic material, the end terminating with a 

 horny shield or nail of various sizes and shapes in the dif- 

 ferent species ; nostrils variously shaped and placed in the 

 different sub-families and genera ; the short legs are feathered 

 usually quite to the tarsus, which is variously scute! late or re- 

 ticulated, toes fully webbed, sometimes somewhat incised, and 

 hind toe simple or barely membranous ; wings moderate or 

 long, pointed, narrow, strong, and elastic ; tail short, usually 

 rounded ; body compressed, neck long, head large — compar- 

 atively. Their anatomical characters are of special interest, 



