MAIL-CLAD ANIMALS. 15 



surface, is protected by a very strong bony armour, 

 which is often elegantly sculptured. Thus their 

 shoulders are encased in one solid shield, and their 

 loins in another, the two shields being connected by a 

 larger or smaller series of movable transverse bands, 

 which permits the creature to roll itself up into a ball 

 after the manner of a hedgehog, and thus present a 



FIG. 6. A Glyptodont, showing the carapace. A, View of entire animal. 

 B, Front end of carapace, c, Back view of same. D and E, Upper and under 

 side of skull. F, Section of tail showing vertebrae inside the bony sheath. 



sphere of plate-armour to an enemy. Still more won- 

 derful, however, is the armour of the extinct Glypto- 

 donts (Fig. 6), whose shield formed a single massive 

 carapace, which may be as much as five feet in length, 

 with a thickness of more than an inch of solid bone. 

 These creatures could not, of course, roll themselves 



