660 CYGNUS MUSICUS. 



inches and two-twelfths; tarsus four inches and two-ticelfths ; 

 middle toe four inches and ten-twelfths, its claw an inch; tail 

 of twenty feathers, rounded; bare space on the forehead, and 

 between the eyes and bill, bright yellow, as is the base of both 

 mandibles, that colour extending in an angular form on the 

 sides of the upper mandibles to beyond , the nostrils; feet 

 black; plumage pure white, the head tinged with orange-red. 

 Female similar to the male, but considerably smaller. Young 

 with the bill dusky at the end, reddish toward the base, the 

 partially bare skin at its base flesh- colour ; the feet reddish- 

 grey ; the plumage pale bluish-grey. 



Male. — The body of this, the largest wild bird, except 

 the Polish Swan, that occurs in Britain, is of an elliptical, 

 rather elongated, and somewhat depressed form ; the neck 

 extremely long and slender ; the head of moderate size, 

 oblong, compressed. The bill is rather longer than the 

 head, straight, higher than broad at the base, gradually de- 

 pressed, of nearly equal breadth throughout, being very 

 slightly narrower toward the end ; upper mandible with the 

 dorsal line, not including the space behind the joint, de- 

 scending, and almost sraight to the unguis, then decurved, 

 the ridge broad and flat at the base, gradually narrowed, 

 beyond the nostrils convex, the sides nearly erect and some- 

 what concave at the base, gradually sloping and becoming 

 more convex, the margins soft, the unguis large, obovato- 

 triangular, convex, thick-edged, and internally grooved. 

 The lower mandible with the intercrural space very long 

 and of moderate width, its membrane bare for more than 

 two-thirds, the crura convex beneath, with their lower out- 

 line very slightly re-arcuate, the laminated margins incli- 

 nate, the unguis very large, obovato-triangular, little convex, 

 with a wide groove on each side ; the gape-line slightly 

 re-arcuate. 



The upper mandible deeply concave, with a medial pro- 

 minent papillate ridge, and on each side an oblique series of 

 transverse flattened tubercles, a submarginal series of incon- 

 spicuous slender lamella 3 , and a marginal series of transverse, 

 more or less oblique, slender, little elevated, obtusely termi- 



