The Divers. 
The Red-throated Diver. The White-billed Diver. The Great Northern Diver. 
downwards towards the tip, and there is scarcely any indication of an angle on the 
lower mandible, whereas in C. adamsi the angle of the genys is strongly marked. 
In the latter bird the colour of the throat and upper fore-neck is purplish instead of 
greenish-blue, and the white edgings to the feathers on the band which crosses the 
throat are broader and longer. In winter plumage the two species are alike, 
but the colour of the bill distinguishes them at this season of the year. 
The White-billed Diver has occurred several times on our coasts, and is perhaps 
more common in winter than has been supposed. Its home is in the Arctic Regions 
of Europe and Siberia as well as North-west America. In habits it does not differ 
from C. glacialis, and the nest and eggs are similar. 
This is a smaller bird than either of the foregoing, and has 
the head and neck of a dove-grey colour; the fore-neck is purplish- 
black, with rows of white-striped feathers on either side of the 
neck. In winter it may be told by its smaller size, the wing 
being from eleven-and-a-half to thirteen inches in length ; 
the upper surface of the body is dark ashy-brown and the wing-coverts are more or 
less spotted with white. The Black-throated Diver is found nesting in the North 
of Scotland, and occurs in winter on our coasts. It nests in Northern Europe and 
Asia as well as in North America, migrating southwards in winter, when it is found 
THE BLACK- 
THROATED 
DIVER. 
{Colymbus arcticus.) 
