208 



VERTEBRATA: AVES OR BIRDS. 



FIG. 244. 



Diver is thirty-one inches long, and its colors are black 

 and white. 



The Grebes are very peculiar-looking birds, which 

 have the bill rather long, slender, and pointed, the nos- 

 trils not lobed, the wings very short, 

 the tail only a tuft of downy feathers, 

 and the plumage of the under parts 

 white and very silky in appearance, 

 and the feet only .partially webbed, 

 and the toes and claws- flat. In the 

 breeding season the head in most spe- 

 cies is ornamented with tufts of feath- 

 ers. When alarmed they quietly 

 sink in the water, and there remain, 

 exposing only the bill. They vary 

 from twelve to thirty inches in length. 

 The Auks or Alcidas are pygopo- 

 dous birds which have the bill gener- 

 ally pointed, compressed, and in many 

 cases modified by ridges, furrows, and processes, which 

 give it a very odd appearance. They are rather stout- 

 bodied birds; and their wings, tail, and toes are very short. 



All the species of the Alcidre 

 belong to the northern regions ; 

 some species come far south- 

 ward in winter. They are 

 known as Auks, Puffins, Guille- 

 mots or Mui-res, according to the 

 kind. They vary from seven to 

 thirty inches in length. 



The Great Auk (Alca impen- 

 nis) is thirty inches long, and the 



Puffin, Mormon arctica, Illigiger. w j n g on ]y fi ve au( J a l ia ]f j nc l les . 



Crested Grebe, 



us, Latham. 



FIG. 245. 



