BRUNNICII'S GUILLEMOT. 457 



A specimen of the bird now before me, brought from 

 Iceland by Mr. Proctor, agrees exactly with Colonel Sa- 

 bine's description of this species in its summer-plumage. 

 The beak is black, its shape has been referred to, the 

 posterior half of the marginal portion of the upper man- 

 dible nearly white, extending from the corner of the mouth 

 to the point where the feathers project on the bill ; the 

 irides dark ; head, throat, neck behind, back, wings, and 

 tail sooty black ; secondaries tipped with white ; belly, 

 and all beneath pure white, running up to a point on the 

 front of the neck ; in the Common Guillemot the white 

 colour ends here in the form of a rounded arch ; legs, toes, 

 and their membranes brownish-black. The whole length 

 eighteen inches. From the wrist to the end of the longest 

 quill-feather eight inches and a quarter. The sexes are 

 alike in plumage. 



This species undergoes the same changes of plumage 

 from season as the U. troile. Colonel Sabine remarks that 

 specimens killed early in June had the throat and neck 

 white, unmixed with black ; towards the end of June the 

 change was in progress, and by the second week in July, 

 as many were found in perfect summer-plumage, with 

 black throats and necks, as were still in change. M. Tem- 

 minck says the young assume, in March, their first sum- 

 mer-plumage. Adult birds lose their black throat at the 

 autumn moult. 



