CHAP, xviii.] BIRDS. 367 



The Grebes are universally distributed. The genera are 

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

 to North and South America. Some ornithologists group these 

 birds with the Colymbidse. 



FAMILY 125. ALCIRZE. (7 Genera, 28 Species.) 

 GENERAL DISTRIBUTION. 



The Alcidse, 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; Ceratorhina (2 sp.), 

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

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

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

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

 constitute the family Uriidae, of some ornithologists. 



General Remarks on the Distribution of the Anser'es. 



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 Palsearctic regions each have seven families of Anseres, 

 two of which, the Colymbidse and Alcidse, are peculiar to them. 

 The Ethiopian, Australian, and Neotropical regions, which all 



