104 



STORY OF THE REPTILES 



formerly turned balls of the old muzzle-loading 



musket. 



Of course the scales of lizards and snakes are 



shields, but, as noticed, some lizards have bones in or 



beneath the skin over the back and rear part of the 



head. A few lizards, the chameleons, and one snake 



are merely warty or tough-skinned. 



Besides this, many modern lizards (as well as the 



old fossils) are plentifully protected with spines. 



These may run along 

 ^v the back and upper 



edge of the tail only, 

 as in the common igu- 

 ana, Tuatera^ croco- 

 diles, the leguan (Fig. 

 54), the Galapagos 

 sea-lizard, and others ; 

 or they may be all 

 over the body, as in 

 our horned toad of 

 the Western plains 

 and the Moloch lizard 

 of Australia (Fig. 55). 

 These spines all grow 

 from scutes that are 



buried in the flesh or skin, but the tips of every scale 



are slightly spinous in some lizards. 



Terrifying Methods 



Besides actually hurting their foes, many reptiles 

 terrify or threaten when they are disturbed, and some 



Fig 



54.— Head of leguan {Iguana 

 rhiyiolophus). 



