104 



STORY OP 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 modem lizards (as well as the 



old fossils) are plentifully protected with spines. 



These may run along 

 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 homed 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. 



Teeeifting Methods 



Besides actually hurting their foes, many reptiles 

 terrify or threaten when they are disturbed, and some 



Fig. 54. — Head of leguan {Iguana 

 rhinolophus). 



