34 



THE WORLD'S BIRDS. 



forms, of even wider distribution. Among the 

 ordinary diving Ducks, the Canvas-back of North 

 America {Nyroca vallisneria) is celebrated for the 

 table ; it much resembles our pochard (A^. ferina), 

 but is much larger. 



FiNFooTS (HeliornithidcB). 



Diagnosis. — Rail-like water -birds with well-developed 

 tails, short legs, and lobed feet. 



Size. — From that of a crow to that of a thrush. 



Form. — Bill like that of many rails, compressed, 

 moderate in length, with central nostrils, and corner 

 of mouth half-way to eye ; feet with short shanks, 

 front toes lobed as in a coot, hind-toe fairly 

 developed ; wings short, like those of a rail ; tail 

 well developed. General appearance much like 

 that of a cormorant, except for wings, bill, and 

 lobed toes. 



Plumage and Colouration. — Feathering close, not 

 loose-textured as in rails ; tail stiff in some. 

 Sometimes a sex-difference, but no seasonal change. 

 Feet bright coloured. 



Young. — Those of the American Heliornis surinamensis 

 said to be naked and carried under wings of 

 parent. 



Food. — Fish and other aquatic animals. 



Gait. — In spite of the short legs they move actively 

 on land, standing semi-erect. They swim and 

 dive well, floating low in the water like a cor- 

 morant. 



Flight. — Direct, by continuous beats of the wing ; they 

 rise off the water awkwardly. 



