The Swans. 35 



I now give a brief, but sufficient, de- 

 scription of the Whooper and Bewick's 

 Swan. Both these Swans have the bare 

 skin in front of the eye yellow, and they 

 ought not to be confounded with the Mute 

 Swan, in which this part is black. 



THE WHOOPER (Cygnus musicus), when 

 adult, is entirely white. The bill is partly 

 yellow and partly black. If a point be 

 taken on the bill about an inch from 

 the forehead, and another on the margin 

 of the upper mandible about half-way 

 between the gape and the tip, and these 

 two points be joined by a line which will 

 be found to pass through the posterior 

 angle of the nostril, then this line will 

 represent the junction of the yellow of 

 the base of the bill and the black of 

 the front half. The length of the upper 

 mandible from the forehead to the tip 

 is about 4*i ; from the eye to the tip, 

 about 5*2 ; and from the gape to the 

 tip, about 4*1. There is no knob or 

 swelling at the base of the upper man- 

 dible. The wing measures from 23 to 

 25! ; the tarsus about 4*3 ; and the middle 

 toe and claw about 67. The tail is 

 rounded, the distance between the tip 

 of the outermost feather and the tip of 



