Order PYGOPODES. 



Family COLYMBID^E. 



THE GREAT NORTHERN DIVER. 



Colymbus glacialis, Linnaeus. 

 Plate 77. 



This large Diver is a winter visitor to the waters of the British coast, and has 

 never been known to nest in our islands, though mated pairs in full breeding 

 plumage are sometimes observed in summer. 



It breeds in Iceland, Greenland, and in the colder parts of North America, 

 whence it migrates southwards in winter. 



The nest, composed of aquatic plants, is always placed either on the shores or 

 on some small island on fresh-water lakes, so that on the least suspicion of danger 

 the bird can slide stealthily into the water. 



The two eggs, varying in ground-colour from greenish to reddish-brown, are 

 spotted with black. 



The food consists of fish and crustaceans, often obtained at a great depth, as the 

 bird, like all the members of this family, is a splendid diver, and can remain under 

 water for a considerable time. It has, in common with the other Divers, a habit of 

 sinking its body when swimming, so much so that sometimes little more than its 

 head and neck are visible. 



During the breeding season it utters a strange melancholy cry, while at other 

 times it has been heard to emit a low croaking sound, according to Macgillivray. 



THE WHITE-BILLED NORTHERN DIVER. 



Colymbus adamsi, G. R. Gray. 

 Plate 77. 



This species differs from the Great Northern Diver in having a heavier and 

 more angular bill of a yellowish ivory colour, while another means of distinguishing 



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