AUKS. 



held out behind, like those of the Waders in 

 flight ; on the other hand, the short wings are used 

 efficiently in these circumstances, like fins; so 

 that the bird may be said literally to fly beneath 

 the surface. " Their movements under water pre- 

 cisely resemble those of the Dyticidcs or common 

 Water-beetles; the principal motion being more 

 or less vertical, instead of horizontal as in the 

 Grebes and Loons ; they are therefore, together 

 with the distinct group of Penguins, the most 

 characteristic divers of the Class." * 



The characters of the Family are, that the beak 

 is varying in length, more or less compressed ; 

 the upper mandible curving to the tip, which is 

 sometimes hooked : the wings are generally short, 

 and in some little more than rudimentary; the 

 tail short and graduated ; the tarsi short and com- 

 pressed ; the toes entirely webbed, the hind toe 

 either wanting or very small. 



These birds frequently associate in immense 

 numbers on rocky islets and precipitous cliffs that 

 overhang the sea, on the shelves and narrow 

 ledges of which they lay their eggs, one only de- 

 posited by each bird; the female keeping it 

 between her feet for the purpose of incubation, 

 as she sits in an erect position. The procuring 

 of the eggs and young of these and similar birds, 

 forms an important means of subsistence to many 

 families. 



The storm-lashed and iron-bound coasts of 

 Northern Europe and America, and of the ex- 

 treme southern portion of the latter continent, 

 with the frozen islands of both the Arctic and 

 Antarctic Oceans, are the dreary homes of the 



* Mr. Blyth, in Cuvier's Anim. Kingd. Lond. 1840. 



