CHAPTER IV; 
DIVERS, GREBES, AND CORMORANTS. 
Divers—A finities and charac- 
teristics—Great Northern Diver 
—Black-throated Diver— Rea- 
throated Diver—Grebes—Char- 
acteristics—Changes of Plumage 
—Great Crested Grebe— Red- 
necked Grebe — Black - necked 
Grebe — Sclavonian Grebe — 
Little Grebe — Cormorants — 
Characteristics — Changes of 
Plumage — Cormorant — Shag— 
Gannet. 
HE birds included in the present chapter 
belong to three well-defined families. None 
of them are so completely pelagic as the Auks, 
and yet, according to season, many of them are 
interesting features in the bird-life of the coast. 
Uufortunately for the summer visitor to the sea- 
side, the Divers will be absent. They are birds 
that resort chiefly to inland districts to rear their 
young, or are only known as winter visitors to 
the British Coasts. The Divers form a small but 
well-marked family known as CoLYMBIDA&, consisting 
of a single genus Colymbus, into which are grouped 
the four species that are now known to science. The 
Divers are allied to the Auks on the one hand, to 
the Grebes on the other, although systematists are 
