480 OENITHOLOGY AND OOLOGY. 



SUB-ORDER ANSERES. 



Family ANATID^. 



The two jaws with transverse lamelliE, alternating and fitting in each other; 

 upper mandible ending in an obtuse rounded nail ; a groove running along both 

 jaws to the nail ; the feathers of the forehead extend forward on the culmen in a 

 rounded or acute outline; those on the side of lower jaw and on the chin extend 

 forward in a similar manner ; commissure straight ; legs short. 



Sub-Family Cygnin^. — The Swans. 

 CYGNUS, LiNN.EUs. 



Cygnus, Linn-«us, Syst. Nat. (1835). (Tj'pe Anns olor, Gm.) Gray. 



Neck very long; bill longer than the head (commissure longer than the tarsus), 

 the basal portion covered by a soft skin extending to the anterior half of the 

 eye; the plane of the upper outline from eye to eye horizontal; the lateral outline 

 extending nearl}' straight to the commissure, or even sometimes widening slightly; 

 not half the width of the bill at tip; nostrils situated in the middle portion of 

 the bill ; lower portion of tibia bare ; the tarsus much shorter than the foot, much 

 compressed, covered with hexagonal scales, which become smaller on the sides and 

 behind; hind toe small, much elevated; the lobe ntirrow; tail of twenty or more 

 feathers, rounded or wedge-shaped; sexes similarly colored. 



CYGNUS AMERICANUS. —Skarpless. 



The American Swan. 



Cygnus Americanus, Sharpless. Doughty's Cab. N. H., I. (1830) 185. Aud. Cm. 

 Biog., V. (1839) 133. lb., Birds Am., VI. (1843) 226. 

 Cygnus ferm, Nuttall. Man., II. (1834) 368. 



Description. 



Bill as long as the head, broad, high at the base; the feathers ending on the fore- 

 head in a semicircular outline; nostrils far forward, the anterior extremity consider- 

 ably more forward than half the commissure; tail of twenty feathers. 



Adult pure-white; bill and legs black; the former with an orange or yellowish 

 spot in front of the eye; less mature specimens with the head above tinged with 

 reddish-brown ; iris brown. 



Length, fifty-five inches; wing, twenty-two; tarsus, four and twenty-five one- 

 hundredths; bill, above, four and twenty one-hundredths inches. 



Hob. — Continent of North America. 



