NATATORES: COLYMBID^E. 28 1 



inches long. The Caspian Tern, 5. caspia, Pallas, of New 

 Jersey and northward, is twenty-one and a half inches 

 long. The Royal Tern, 5. rcgia, Gamb., of the Middle 

 and Southern States, is twenty-one inches long. Tru- 

 deau's Tern, *S. Trudeauii, Aud., of New Jersey, is fifteen 

 inches long. Wilson's Tern, S. Wilsoni, Bonap., from 

 Texas to Labrador, is nearly fifteen inches long. The 

 Arctic Tern, 5". macroura, Naum., of the coast of New 

 England and northward, is fourteen and a half inches 

 long. The Roseate Tern, 5. paradisca, Brtinn, from New 

 York to Florida, is sixteen inches long. The Least Tern, 

 S.frenata, Gamb., of North America, is eight and three 

 quarters inches long. The Short-tailed Tern, S.plumbca, 

 Wils., of North America, is nine and a half inches long. 



The Genus Rhynchops has the lower mandible longer 

 than the upper. The Black Skimmer, R. nigra, Linn., of 

 the Atlantic, is nineteen inches long, wing fourteen and a 

 half inches. It skims its food from the surface of the water. 



COLYMBID^:, OR DIVER FAMILY. - - This Family com- 

 prises birds which are remarkable for their power of 

 swimming and diving, and which move with difficulty 

 upon the ground. 



Great Northern Diver, or Loon, C. torquattes, Briinn. 



The Genus Colymbus Divers proper has the bill 



