110 ANATID.E. 



to much more advantage on the land, where, by choice, they 

 spend the greater portion of their time. The stomach of a 

 specimen examined by Mr. Thompson contained only minute 

 seeds and gravel. 



Young birds as they appear here in the plumage of their 

 first winter are greyish-brown. At their second winter, when 

 they liave acquired the white plumage, the irides are orange ; 

 the head and breast strongly marked with rusty red ; base of 

 the beak lemon yellow ; Avhen older some continue to exhibit 

 a tinge of rust colour on the head, after that on the breast 

 has passed off. The adult bird is of a pure unsullied Avhite ; 

 the base of the beak orange yellow ; the irides dark ; the 

 legs, toes, and membranes black ; the figure at the com- 

 mencement of this subject shows the distribution of black 

 and yellow on the beak, which is liable to a little variation. 



The whole length three feet ten inches, to four feet two 

 inches. From the carpal joint to the end of the longest 

 primary twenty-one inches ; the second and third quill-fea- 

 thers longer than the first and fourth ; tail-feathers twenty ; 

 in young birds I have found but eighteen, and in one in- 

 stance nineteen. 



M. Temminck says this species breeds in Iceland in May, 

 and has been taken in the winter in Picardy. 



In anatomical structure this new species differs much more 

 decidedly from the Hooper than in its external characters. 

 The principal and most obvious difference is in the trachea, 

 which forms one of the best distinctions in the separation of 

 nearly allied species throughout this numerous family. The 

 tube of the windpipe is of equal diameter throughout, and 

 descendinir in front of the neck enters the keel of the sternum 

 which is hollow, as in the Hooper, traversing its whole length. 

 Having arrived at the end of the keel, the tube then gra- 

 dually inclining upwards and outwards passes into a cavity 

 in the sternum destined to receive it, caused by a separation 



