THE ARMADILLOS 1387 



THE ARMADILLOS 

 Family 



The armadillos, together with their near ally the pichiciago, constitute a well- 

 defined South-American family distinguished from other living Mammals by the 

 development of a number of bony plates in the skin, so as to form a more or less 

 complete shield enveloping the body, and it is from the presence of this bony curiass 

 that the members of the family derive their distinctive Spanish title of armadillos. 

 In general the bony shield of the back is formed by the union of quadrangular or 

 many-sided plates, and is divided into an anterior and posterior solid portion, sepa- 

 rated by a series of movable transverse bands, varying in number from three to thir- 

 teen. The anterior shield, into which the head and fore-limbs may be more or less 

 completely withdrawn, is termed the scapular shield; while the posterior portion, 

 which is notched for the tail, is known as the lumbar, or pelvic shield. The mov- 

 able bands are composed of parallel rows of similar plates connected by flexible 

 skin, and in some cases the degree of flexibility in this region is so great as to allow 

 of the animal rolling itself into a complete ball. One peculiar genus of extinct 

 armadillo differs from all living forms in that the whole body shield was com- 

 posed of these movable plates. Usually a certain number of hairs protrude between 

 the bony plates of the armor, and in some cases these are so numerous as almost to 

 conceal the armor, and give the appearance of a furry animal. Each bony plate is 

 sculptured, varying in pattern in the different genera, and it is overlain by a horny 

 shield, developed in the cuticle or epidermis; the bones themselves belonging to the 

 true skin. The upper surface of the head is also protected by an armor of similar 

 structure, and the tail is usually encircled by a series of bony rings. The limbs are 

 likewise protected externally by a number of bony plates embedded in the skin, 

 which do not, however, articulate together by their edges. The fore-feet are pro- 

 vided with very powerful 

 curved claws adapted for 

 digging, and varying in 

 number from five to 

 three; while in the hind- 

 feet the claws are of 

 smaller size, and invari- 

 ably five in number. The SKELETON OF ARMADILLO. 



numerous teeth are small 



and simple, looking like small pegs fixed in the jaws, and in one genus the anterior 

 teeth are preceded by a deciduous milk series. The tongue is considerably elon- 

 gated, although to a less extent than in the ant-eaters. 



The elongated skull is characterized by the full development of the zygomatic 

 or cheek arch, and the collar bones are complete. In the hind-limbs the bones of 

 the second segment (tibia and fibula) differ from those of the other existing mem- 

 bers of the order by being united at their lower extremities. Another peculiarity is 

 that a variable number of the vertebrae in the middle of the neck are likewise 



