100 DIVERS.— GREBES. 



sively, to the surface of the water : then* plumage is very close 

 in structure, and even frequently presents a smooth surface and 

 a silvery brightness. They swim perfectly, with the body entirely 

 under water, and use their wings almost as if they were fins. 

 This family is divided into three tribes, namely: 



1st. The Divers, in which the beak is moderate, strong, 

 straight, very pointed, and compressed, and the nostrils are 

 lateral, linear, and half closed by a membrane. 



•2nd. The Auks, in which the beak is very compressed, 

 trenchant, and ordinarily furrowed transversely. 



3d. The Penguins, in which the beak is pointed or hooked, 

 and the vrings are furnished only with feathers, w^hich are so 

 short that they resemble scales. 



3. The Divers, are sub-divided into Divers properly so called, 

 Grebes, Guillemots, &c. 



4. The Divers properly so called, — Colymbus, — are recog- 

 nised by their long toes, which are entirely palmate, and aniied 

 with pointed nails ; the thumb is short and provided with a small 

 membrane. Their tail is very short and round. These birds 

 never quit the water except during the season of laying, and 

 then they walk by the assistance of their wings ; if these supports 

 fail them, they fall upon the belly, and have great difficulty in 

 rising. They keep habitually under water, and scarcely show 

 any thing but the head to breathe from time to time. They fly 

 well, but rarely, and dive at the flash of a gun, without attempt- 

 ing to fly. They feed on fishes, spawn, and aquatic insects. The 

 most common of its tribe, in the United States, is the Loon, or 

 Great Northeni Diver, — Colymbus glacialis. 



5. The Grebes, — Podiceps, — {Plate 6, fig. 2.) in place of true 

 palmate membranes, have the toes widened like the Grallatoriae 

 of the genus Fulica, and the anterior ones being united only at 

 the base by membranes. They live on lakes and ponds, and 

 build among the rushes. They swim with ease, and dive fre- 

 quently ; the semi-metallic lustre of their plumage has caused 

 their skins to be applied to the same use as fur. There are 

 several species in Europe which are not well distinguished ; the 

 largest is of the size of a duck, and the smallest is not larger 

 than a quail. 



6. The name of Gl-illemots, — Cria, — is given to Divers that 

 want the thumb, and that have shorter wings than the preceding. 



3. How are the Divers divided ? 



4. How are Divers properly so called, characterised ? What are their 

 habits ? What is the Loon ? 



o. What are the characters of the Grebes ? 

 6. What are Guillemots ? 



