THE TRUE SWANS. 247 



black bill. It has long been naturalised in this country, and 

 has repeatedly hatched its young in captivity, so that there is 

 always a strong probability of the cygnets escaping before they 

 can be pinioned. Another North American species which 

 has been stated but on far weaker evidence to have been 

 found at long intervals in the shops of Edinburgh poulterers, 

 is C. americamis, a bird which is smaller than the Whooper, 

 though larger than Bewick's Swan, which it resembles in 

 having patches of small size at the base of the bill, but of a 

 deep orange-colour. In the adults of our Whooper and the 

 American Trumpeter Swan, the loop of the trachea between 

 the walls of the keel of the sternum takes a vertical direction, 

 whereas in Bewick's Swan and in C. americanus the bend is 

 horizontal; but in immature birds these distinctions are less 

 marked, and are not absolutely invariable." 



I. THE WHOOPER SWAN. CYGNUS MUSICUS. 



Anas cy 'gnus, Linn. S. N. i. p. 194 (1766 ; pt.). 

 Cygnus musicuS) Macg. Br. B. iv. p. 659 (1852); Dresser, B. 

 Eur. vi. p. 433, P 1 - 4 *9, fig- 4 (1880) ; B. O. U. List Br. 

 B. p. 120 (1883); Saunders, ed. Yarr. Br. B. iv. p. 308 

 (1885); Seebohm, Br. B. iii. p. 480 (1885); Saunders, 

 Man. p. 401 (1889); Lilford, Col. Fig. Br. B. part xxv. 

 (1893); Sharpe, Cat. B. Brit. Mus. xxvii. p. 26 (1895). 



(Plate LV. Fig. i.) 



Adult Male. White all over, with occasionally some ferrugin- 

 ous-yellow on the head ; " anterior part of the bill depressed and 

 black, the basal part, with the lores, yellow, this colour extend- 

 ing forward along each lateral margin of the upper mandible, 

 beyond the openings of the nostrils, which are black; the black 

 colour only reaches half-way to the gape; legs, toes, and their 

 membranes black. Total length, about 5 feet ; oilmen, 4-2 ; 

 wing, 25-5 ; tail, 8-5 ; tarsus, 4-2 " (Salvador*}. 



Adult Female. Similar to the male, but a little smaller. 

 Young Birds. Greyish-brown ; " beak first of a dull flesh- 

 colour, the tip and the lateral margins black, posteriorly black, 

 with a reddish-orange band across the nostrils, and with the 

 base and lores pale greenish-white " (Salvador!) ; "feet flesh- 

 colour" (Saunders}. 



