LINN^US. 285 



The class of Birds comprehends 930 species^ which 

 are characterized by the colours of the plumage, the 

 forms of the feathers, the existence of wattles, spurs, 

 and various other circumstances. 



The third class. Amphibia, is composed of anic 

 mals not, strictly speaking, capable of living both in 

 air and in water, but having the power of suspend- 

 ing their respiration in a more arbitrary manner 

 than others. They are arranged under four orders ; — 



I. Reptiles. Amphibious animals respiring through 

 the mouth by means of lungs ; and furnished with four 

 feet. 



To this order belong the tortoises, dragons, croco- 

 diles, lizards, toads, and frogs, which are disposed 

 into four genera, containing 83 species. 



II. Serpentes, Serpents. Respiring through the 

 mouth by means of lungs; destitute of feet, fins, and 

 ears. 



There are six genera, and 132 species. 



III. Meantes, Gliders. Respiring by means of gills 

 and lungs ; furnished with feet and claws. 



There is only one species, the lizard-syren of Ca- 

 rolina. 



IV. Nastes, Swimming Amphibia. Respiring at will 

 by means of gills and lungs : the rays of the fins cartila- 

 ginous. 



These animals, of which 76 species are enume- 

 rated, are referred to fourteen genera, — the lamprey, 

 ray or skate, shark, chimaera, frog-fish, sturgeon, 

 lump-fish, oldwife-fish, bonyskin-fish, sun-fish, por- 

 cupine-fish, trumpet-fish, pipe-fish, and dragon-fish. 



