Mr. Yarrell on a new Species of Wild Stuan. 453 



ing his imperishable name to so valuable and interesting an 

 example among his own most admired and favourite subjects. 



Ordo. Natatoues. Illiger. 



Fam. ANATiDai. Leach. 



Genus. Cygnus. Meyer. 



Bewickii. C. rostro semicylindrico atro, basi aurantiaca, cor- 

 pore albo, caud^ rectricibus 18, pedibus nigris. 



And the better to distinguish the Anas Cygnus (ferus) of 

 Linnaeus, I venture to propose the following specific character : 



ferns. C. rostro semicylindrico atro, basi lateribusque (his 



ultra nares) flavis, corpore albo, caudd rectri- 

 cibus 20, pedibus nigris. 



EXPLANATION OF THE PLATES. 



Tab. XXIV. 



Fig. 1. Side view of the sternum and trachea of Bewick's Swan. 

 a. The keel; b. sternum; c,c. trachea; d,d. muscles 

 of voice; e. bone of divarication ; f. bronchiae. 

 2. Front view of the same part, the anterior portion of the 

 trachea turned aside to show the inner ascending part 

 of it, the muscles of voice, and the tendinous fascia by 

 which both are supported. 



Tab. XXV. 



Fig. 1. Upper surface of the sternum of a young bird. 



Fig. 2. 



