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THE TORTOISE TRIBE*. 



JL HIS is one of the dullest and most sluggish of 

 all the animated tribes. Those species that live 

 on land subsist on worms and snails ; the others, 

 that inhabit the ocean, feed principally on sea- 

 weeds. 



Their body is defended by a bony covering, 

 coated with a horny, scaly, or a cartilaginous integu- 

 ment. This consists of two plates; the one above, 

 and the other below, joined together at the edges. 

 The upper one is convex, and, in general, is made 

 up of thirteen plates in the middle, surrounded by 

 a margin containing twenty-four. The ribs and 

 back-bone are ossified into this, and the other, the 

 breast-plate, contains the breast-bones or sternum. 

 At each end of the two united shells is a hole ; 

 the one for the head, neck, and fore-feet to pass 

 through, and the other, at the opposite end, for 

 the hind-feet and tail. From these shells the ani- 

 mal is never disengaged, and they defend it suffi- 

 ciently from every enemy but man. 



The head is small, and, in the place of teeth, 

 has hard and bony ridges. The upper jaw closes 



* This tribe commences the Linnean order of ReptjLes. 

 B a 



