SOME EXTINCT ARGENTINE MAMMALS 93 



backed form, while its margins lack the prominent knobs 

 characterising those of the preceding group. On closer 

 examination it will be found that each of the com- 

 ponent plates of the carapace, instead of being polygonal 

 and marked by a rosette of lines, is rhomboidal and pierced 

 by from two to five large circular holes. From the analogy 

 of the living hairy armadillo — known in Argentina by the 

 name of peludo, or hairy animal — it is quite evident that 

 during life the holes in the plates of the carapace of this 

 extinct monster — which, by the way, may be known as 

 the "club-tailed glyptodon," or technically as Daedicurus — 

 must have formed the exits of large bristles, which were 

 equal in diameter to a cock's quill, and were doubtless many 

 inches in length. The whole body of the animal must, 

 therefore, have resembled a gigantic porcupine. Still more 

 extraordinary is the conformation of the huge tail, which 

 had a length of about five feet. At its base this appendage 

 was encircled by about half a dozen double bony rings, 

 nearly as large at the base as the iron hoops in the middle 

 of an ordinary beer-barrel, their component plates being 

 pierced by the aforesaid holes for bristles. The whole of 

 the terminal half of the tail is formed by one continuous 

 piece of hollow bone, which, if we exclude whales, is one 

 of the most massive bony structures in the animal kingdom, 

 and is almost as much as a man can lift. Starting at its 

 base in the form of a nearly cylindrical tube, this sheath 

 rapidly expands at the sides, and becomes flattened on the 

 upper and lower surfaces, until at the tip it finally assumes 

 the form of a depressed, flattened club, which would have 

 formed a most effective weapon for a giant. Along the 

 sides of its extremity this club is marked by a number of 

 oval depressed discs, showing a sculptured pattern of 

 ridges and grooves radiating from the centre, and some 



