DIVERS, 



99 



words, they are web-footed. Their feet are made for natation, 

 that is, they are placed far back on the body, and sustained 

 by strong, compressed tarsi. A close, lustrous plumage imbued 

 with an oily fluid, and a thick down next to the skin, protect 

 them against the water upon which they dwell. They are the 

 only animals of this class, in which the neck exceeds — and some- 

 times very much— the length of the feet, for the reason that when 

 swimming on the surface of the water, they often have to seek 

 animals upon which they feed in its depths. The localities which 

 they inhabit, removes most of them from the empire of man, and 

 in many respects even from the investigation of naturalists. Birds 

 of this order generally possess a system of organization which is 

 strong and appropriate for extensive flight ; their sternum is very 

 long, affording ample protection to most of their viscera, and has 

 but one notch or oval hole on each side, which is filled by mem- 

 brane, so that this bone affords a wide surface for the attachment 

 of the depressor muscles of the wings. This order is divided into 

 four families according to the following characters : 



f Having excessively short wings, and the legs ^ 

 placed so far back, that they are obliged, when on ! 

 land, to preserve an almost vertical position. They f 

 fly little, or not at all. J 



Having the 

 wings of ordi- 

 nary length, or 

 even very long, < 

 and the feet so 

 placed as to ena- 

 ble the animal to 

 walk when in a 

 horizontal posi- 

 tion. 



The beak 

 horny 



:'{ 



The thmnb free, 

 or wanting. Wings 

 excessively long. 



f The thumb united ^ 

 j to the other toes by 

 j a common mem- 

 tbrane. Wings long. 



ree, "] 

 ngs j- 



(Families.) 



BilACHYPTER.^. 



or 

 Divers. 



LONGIPENNES. 



TOTIPALMAT-^ 



The beak covered by a soft 1 

 skin, and the edges furnished ^Lamellirostres. 

 with transverse lamellEe, or very { 

 , fine teeth. J 



FAMILY OF BRACHYPTER^, OR DIVERS. 

 2. They have the legs placed farther back than all other birds, 

 which renders it laborious for them to walk, and generally obliges 

 them to keep in an erect position when on land. (Plate 6, fig, 

 I, and 2.) As most of them fly badly, and as many of them 

 cannot even fly at all, in consequence of the extreme "« shortness 

 of their wings, they may be regarded as belonging, almost exclu- 



2. What are the characters of the Brachypterse ? What are their habits ? 

 How is this family divided ? 



