21 



Order I. CHELONIA. Brogniart. 



CHARACTERS. 



1. The body is protected by a bony covering formed of the vertebrae of the 

 thorax, back and loins, and by the ribs, of which there are eight pair, 

 greatly developed, and joined to each other by suture; under this shell or 

 carapace are placed the bones of the shoulder and pelvis, and beneath it 

 can often be retracted the head and anterior extremities in front, and the 

 posterior extremities and tail behind. 



2. This bony box is completed below by a broad sternum or plastron formed of 



several pieces joined solidly to each other, and most commonly also to the 

 carapace or shell. 



3. The head, neck, and tail, are the only movable parts of the spinal column. 



4. The jaws are covered with a horny substance; and are always destitute of 



teeth, properly speaking, though their cutting margins are often serrated. 



5. The nostrils are anterior, approximated, and are simple or tubular. 



6. The eyes are always furnished with three lids. 



7. The external meatus of the ear is covered with the skin. 



8. The tongue is fleshy, short, thick, depressed, and covered with fleshy 

 filaments. 



