CHAP. XVIII.] BIRDS. 367 



The Grebes are uuiversally distributed. The genera are 

 Podiceps (26 sp.), cosmopolitan ; and Podilymhus (2 sp.), confined 

 to North and South America. Some ornithologists group these 

 birds with the Colymbidse. 



Family 125.— ALCID^. (7 Genera, 28 Species.) 



General Distribution. 



Neotropical 

 Sub-regions. 



Nearctic 

 Sub-regions. 



Pal-earctic 

 Sub-regions. 



Ethiopian 

 Sub-regions. 



Oriental 

 Sub-regions. 



Australian 

 Sub-regions. 



1 4- 1-3.4. 



The Alcidce, comprising the Auks, Guillemots, and Puffins, 

 are confined to the North Temperate and Arctic regions, where 

 they represent the Penguins of the Antarctic lands. One of 

 the most remarkable of these birds, the Great Auk, formerly 

 abundant in the North Atlantic, is now extinct. The genera are 

 as follows : — 



Alca (2 sp.), North Atlantic and Arctic seas ; Fratercula (4 

 sp.), Arctic and North Temperate zones ; Ceratorliina ( 2 sp.), 

 North Pacific ; Simorhynchits (8 sp.), North Pacific ; Brachy- 

 rhamphus (3 sp.), North Pacific to Japan and Lower California ; 

 Uria (8 sp.), Arctic and North Temperate zones ; Mergulus (1 

 sp.). North Atlantic and Arctic Seas. The last three genera 

 constitute the family XJriidse, of some ornithologists. 



General Bemarhs on the Distribution of the Anseres. 



The Anseres, or Swimmers, being truly aquatic birds, possess, 

 as might be expected, a large number of cosmopolitan families 

 and genera. No less than 5 out of the 8 families have a world- 

 wide distribution, and the others are characteristic either of the 

 North or the South Temperate zones. Hence arises a pecu- 

 liarity of distribution to be found in no other order of birds ; 

 the Temperate being richer than the Tropical regions. The Ne- 

 arctic and Pala^arctic regions each have seven families of Anseres, 

 two of which, the Colymbidce and Alcidae, are peculiar to them. 

 The Ethiopian, Australian, and Neotropical regions, which all 



