NATATORES I ANATID^E. 267 



Rio Grande, is twenty-four inches long, and the wing 

 ten inches. 



The Brown Tree-duck, D. fulva, Burm., of California 

 and southward, is twenty inches long, and the wing over 

 nine inches. 



Anatinae, or River Ducks, have the legs shorter than 

 geese, the lobe of the hind toe narrow, and much re- 

 stricted. Eight genera are found in North America. 



The Genus Anas has the bill broad, depressed, longer 

 than the head, and the tail pointed. 



The Mallard, or Green-Head, A. boschas, Linn., of North 

 America and most of the Old World, is twenty-three inches 

 long, and the wing eleven inches ; the head and neck 

 bright grass-green, with a violet gloss ; a white ring 

 around the middle of the neck, below which and on the 

 fore part and sides of the breast the color is dark brown- 

 ish-chestnut ; speculum purplish violet, terminated with 

 black. This is the original of the common domestic duck. 



The Black Duck, A. obscura, Gm., of the Atlantic region 

 of North America, is twenty-two inches long, and the 

 wing twelve inches ; general color bluish brown. 



The Genus Dafila has the bill long and narrow, tail 

 pointed. It is represented by the Pintail, or Sprigtail, 

 D. acuta, Jenyns, of North America and Europe, which 

 is thirty inches long, and the wing eleven inches. 



The Genus Ncttion has the bill unusually narrow. 



The Green-winged Teal, N. carolinensis, Baird, of North 

 America, accidental in Europe, is fourteen inches long, 

 and the wing seven and two fifths inches ; and distin- 

 guished by the broad rich green speculum. 



The English Teal, N. crccca, Kaup., of Europe, acci- 

 dental in North America, is similar to the preceding. 



The Genus Qucrquedula has the bill narrow, and a 

 little longer than the foot. 



The Blue-winged Teal, Q. discors, Steph., of North 



