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 
