CHELONIA OR TURTLES. 



217 



SUB-SECTION II. 

 THE ORDER OF CHELONIA OR TESTUDINATA OR TURTLES. 



THE Chelonia are reptiles which have a shield or shell 

 upon the back, called the carapace, which is connected by 

 bridges to another shield 

 below, called the plastron, FIG. 219. 



the whole forming a hard 

 covering for the soft organs 

 of the body. This hard 

 formed of the 



covering 



is 



greatly expanded ribs and 

 sternum, together with os- 

 sified skin, and is covered 

 with horny scales. The 

 head, neck, and tail are the 

 only movable parts of the 

 spinal column. The jaws 

 are covered with a horny 

 substance, and are destitute 

 of true teeth ; the tongue is 

 short, thick, and covered 



Skeleton of a Turtle, plastron removed. 



with fleshv filaments- thp <, cervical vertebiw ; pA, phalangea ; 



5l V c, carpus ; ru, radius and ulna ; h, hume- 



and 



rus ; 



sc, scapula ; cl, clavicle ; co, coracoid 



cmrl fli n6; ^' d r8al vertebrffi ; ^ P elvis ! / 



< femur; tf, tibia and fibula; ts, tarsus; 



mt > metatarsus; ps, phalanges. 



nostrils are anterior, 

 near together; 

 have three lids. 



The Turtles may be divided in two Sub-orders the 

 AMYRE, including all such as have feet instead of paddles, 

 as the Land and Fresh-water Turtles, as the Gophers, 

 Wood Tortoises (Fig. 251), Terrapins, Box Turtles (Fig. 



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