V. 
THE COMMON GUILLEMOT. 
This bird was shot in Summer in Loch-na-Nuagh, and sketched at once. It 
corresponded in all respects with Yarrell’s description. The Guillemot in the previous 
plate, and others in winter plumage in Glasgow Market in January, had the legs 
and toes orange-yellow, membranes olive and claws black, instead of all black, as 
in Yarrell’s description of the summer plumage of the adult bird. Yarrell does 
not mention this difference as characteristic of any state of the plumage. It is 
hard to believe that the legs should change colour twice a-year, and we conjecture 
from analogy that the yellow colour of the legs belongs to the adult bird : but 
for this we have no authority. Yarrell also states that the young bird (the 
plumage of which resembles the winter plumage of the adult) retains the white 
throat only “till the first spring moult produces the ordinary plumage of summer;” 
but in Loch-na-Nuagh we have seen at the end of June flocks of Guillemots, some 
with white and others with black throats and all with black legs. As there is 
no known breeding place at all near, we suppose that these were all birds of the 
previous year, driven from the breeding stations, and that many do not assume the 
black throat till the second year. 
