20 



they are awkward and ungainly, but in the water they are ex- 

 tremely agile, swimming with their wings when beneath the surface 

 and using their feet as a rudder. Of the dozen species commonly 

 recognized, several are represented in Cases J and K. 



Order VI, Pygopodes, includes four well-marked families of 

 diving birds — the Grebes (family Podicipidcc), the Loons (family 

 UrinatoridcE), and the Auks (family Alcidte). The Grebes are 

 tailless, small-winged divers, with the toes lobated instead of 

 webbed, and with many peculiarities of internal structure. They 

 are among the most expert of diving birds, number about thirty 

 species, and are represented in nearly all parts of the world. The 

 North American species will be found in Case F, the South 

 American in Case J, and those of other countries in Case L. 



The T.oons are mostly birds of the high North, forming only 

 one genus, and numbering about five species, all of which are 

 found in North America (Case F), as well as in Northern Europe 

 and Asia (Case L). They are large birds, excellent divers, and 

 rather solitary in their habits. 



The Auks, rather near allies of the Loons, are also boreal in 

 distribution, being most numerously distributed along the shores 

 of the North Pacific Ocean, to which several of the species 

 are wholly restricted. They are variable in size and appearance, 

 as may be seen by comparing the Auklets (Cases F and L) with 

 the Great Auk and the Puffins. They are rather poor fliers, but 

 expert divers and swimmers, using their wings under water in 

 swimming, so that they may be said to fly in the water as well as 

 in the air. The Great Auk (Fig. 7) is believed to be extinct, no 

 living example having been seen for nearly half a century, and 

 but few specimens exist in museums. A fine skeleton and a 

 mounted skin, however, may be seen in Case F, where the accom- 

 panying labels give a brief account of the bird's history. 



Order VII, Lottgipennes, includes the Gulls, Terns, and Skim- 

 mers. The Jaeger Gulls (family Stercorariidce) are predatory 

 and somewhat Hawk-like in appearance, especially when flying. 

 They pursue their relatives, the Gulls, and rob them of their fish. 

 Of the six known species two are antarctic and four arctic or sub- 

 arctic in their distribution. (See Cases F and L.) 



