1 84 



THE EDENTATES. 



in form the second neck vertebra of many 

 marsupials. The dorsal vertebrae have high 

 vertical processes, and the lumbar vertebrae 

 have in addition to these very high oblique 

 processes. On the expanded ends of these 

 vertebral processes rests the dorsal shield. 

 The hinder portion of the pelvis is remark- 

 ably large, and often comprises nine sacral 

 vertebrae; it also has strong processes serving 



as supports for the dorsal shield. The tail is 

 long and thick; the vertebra? of the tail like- 

 wise carry strong vertical, oblique, or trans- 

 verse processes as supports for the separate 

 parts of the tail-sheath. The limbs of the 

 armadillos are short, and their bones are pro- 

 vided with well-marked ridges for the attach- 

 ment of the muscles. The humerus is twisted, 

 the ulna has a prolongation reaching far 



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Fig. 241. The Giant Armadillo (Prioiiodoii giga 



beyond the elbow, and the thigh has a third 

 trochanter. While the bones of the fore-legs 

 enjoy a great degree of mobility, the tibia 

 and fibula are fused at the ends and separate 

 only in the middle. The toes are armed 

 with stout burrowing claws. The ribs are 

 often so broad that their edges touch or even 

 overlap one another. 



The most remarkable character of the 

 armadillos arises from the development of a 

 dermal skeleton composed of small plates, 

 mostly hexagonal, laid edge to edge, and 

 adorned with peculiar markings on the sur- 

 face. These thin plates, which in the living 

 animal are flexible, are composed of true 

 bone tissue overlaid with a horny covering. 

 In most cases they form a series of three 

 shields, one for the head, a second for the 

 shoulders, and the third for the hinder part 

 of the back. The two latter are separated 



by transverse bands varying in number. 

 These transverse bands are connected to- 

 gether by a flexible integument, so that the 

 animal can easily enough bend the head and 

 back, and can even roll itself up into a ball. 

 The tail is usually complete and surrounded 

 by plates arranged in rings. The sides of 

 the head, the neck, and the limbs are covered 

 with isolated plates or horny scales belonging 

 to the epidermis. On the belly there is only 

 a firm, tough skin, almost naked. Between 

 the plates and on the edges of the dorsal 

 shields are to be seen strong bristles fre- 

 quently grooved in rings. 



All armadillos live in holes in the ground, 

 which they excavate with remarkable rapidity, 

 and which they never leave voluntarily except 

 at night. They then go out in search of 

 their food, which consists of all kinds of 

 things. They devour everything that they 



