DIVERS. 



405 



mergansers, having the characteristics with which such habits are 

 connected carried out to a still greater degree of completeness. 

 Their plumage is deep, close, silky, and extremely glossy. The 

 bill is long and sharp ; the wings, small, concave, and composed 

 of stiff feathers, are used for the purpose of giving additional im- 

 petus to the body when diving. The legs are placed as far back 

 as possible, the tarsus is flattened so as to cut the water, and the 

 toes, either lobated or webbed, are so arranged as to fold up into 

 a small compass when drawn towards the body, in order to give 

 the back-stroke. The tail is short or wanting, and the body 

 flat ; hence it appears to float deeply on the surface of the water. 

 Necessarily embarrassed and awkward upon land, the Colymbidae 

 are alert and vigorous in their congenial element, from which they 

 can seldom be forced to take wing, trusting rather to diving than 

 to flight for safety ; they rise, indeed, with difficulty, but having 

 attained a due elevation, sweep along very rapidly, and are capable 

 of a long-sustained flight. Their nest is always placed on the 

 immediate margin of the water, amid the floating herbage that 

 abounds in the localities they generally inhabit. These birds 

 swim and dive with equal ease, and can remain submerged for a 

 long period. This family includes the True Divers, the Grebes, 

 and the Sun-Grebes. 



Sub-Family I. 



THE TRUE DIVERS. COLYMBINiE.* 



General Characteristics.— Bill long, straight, with the tip curved and the sides 

 compressed ; the nostrils basal, lateral, and placed in a groove, with the opening 

 linear and pervious ; the wings long and pointed ; the tail very short ; the tarsi short 

 and much compressed ; the toes long, the fore toes united together by an entire web, 

 the hind toe short, and slightly margined by a membrane. 



These birds are founo in the Arctic circle, but migrate to the 

 more temperate climates during severe winters. They are observed 

 on th; sea-coast, as also on lakes and ponds. They are usually 

 met with in pairs, or in small parties, swimming about in search 

 of fish and other aquatic animals, which constitute their food. 

 Owing to the flatness of their bodies, they lie deep in the water, 

 so that when resting on the surface little more than their neck is 



* Ko\viJ.^r]Tris, colymbetes, a diver ; whence "colyrabus," a pond to szuini in. 



